WO2014087161A1 - Improvements in and relating to fabrics - Google Patents

Abstract

A multi-layered fabric including a first layer (29) comprising a woven or knitted fabric having an optical porosity of between 0.06% and 35%, or a porosity of between 50% and 95%; and, a second layer (28) comprising a nonwoven fabric or web having an optical porosity of between 0.1% and 15%, or a porosity of between 75% and 98%.

Description

Improvements in and Relating to Fabrics

The present invention relates to multi-layered fabrics for example, though not exclusively, for use in articles containing natural and/or synthetic fillings, such as down and/or feathers or the like, for thermal insulation or acoustic insulation.

High quality filled products (e.g. duvets, pillows and similar textile articles such as quilts, mattress toppers, sleeping bags, outdoor jackets/clothing, gloves) currently typically consist of an inner insulation (filling) material consisting of feathers and/or down that is retained by an outer covering fabric. In many instances, e.g. to effectively retain the insulation material during use, the outer fabric must be of a tightly woven fabric construction with a minimum inter-yarn pore size (i.e. the size of the spaces between yarns) that prevents components of the filling (e.g. parts of the feather or down) from being able to penetrate the outer fabric during repeated mechanical agitation or washing of the entire assembly. This is particularly challenging in respect of the shaft, distal barbules or proximal barbules of feathers and down fillings because of their small diameter relative to the inter-yarn pore sizes of the covering fabric.

Any article in prolonged contact with human skin, or creating a microclimate around a person, must allow the passage of excess heat and moisture vapour to the external environment to meet comfort requirements. This is particularly so when the ambient conditions are warm (ca. 14-30°C). The materials of the covering fabric, and filling materials, each introduce airflow resistance between a user and their immediate environment. Thermal and osmotic gradients can be adversely affected as a result. A suitable air permeability and rate of moisture vapour transfer from the user to the immediate environment are particularly important requirements of the covering fabric and are largely affected by its thickness and porosity.

The requirement for a tightly woven construction of the covering fabric necessary to prevent penetration of filling (e.g. feather) components, is a major barrier to increasing the air permeability of the outer cover fabric so desirable in articles of clothing and bedding. This severely limits any desirable improvements in air permeability or moisture vapour transport in such articles. It also severely limits options for the use of alternative fabric constructions, such as those with a more open construction that could otherwise provide improved handle and aesthetics, technical function and cost-effectiveness. There is also an economic and technical limitation to the minimum basis weight (gm ²) of the outer fabric that can be used because of the high packing density of yarns and low air permeability associated with its tightly woven construction. Furthermore, the process of assembling high quality duvets and pillows is a lengthy, labour- intensive process that involves extensive sewing operations and the provision of an alternative, more rapid and cost-effective means of constructing duvet and pillow assemblies containing feather and down insulation materials is desirable.

The current invention seeks to address these matters.

At its most general, the invention is to employ a fabric or web of nonwoven construction (e.g. thermoplastic polymer fibres) as a barrier to feather or down penetration through an adjacent woven fabric layer, which may serve as an outer cover layer for e.g. an article of clothing or bedding. Since the woven fabric layer is no longer required to provide feather penetration resistance alone, and may work in synergy with the adjacent nonwoven fabric. The packing of the constituent yarns and construction of its weave need not be as dense/close and can possess a larger pore size, greater porosity, air permeability and breathability which would not otherwise be possible were it serving as the sole barrier to penetration by elements of the filling material (e.g. feather quills, or similar filling fibres).

Down and Feather mixes are particularly, but not exclusively, referenced due to their widespread use in industry as thermal insulators and renowned difficulty to contain, sometimes even in closely woven, low permeability materials. It is suggested, but not asserted, that this is due to the fractal morphology of down, which includes fibrils (e.g. between 2-6μηι diameter, 100-500μηι length) extending from sub branches (e.g. between 8-20μηι diameter, 0.5-3.5cm length) that in turn project from a central core. Figure 1 B shows an example Scanning Electron Microscope (SEM) Image showing the sub branches and fibrils extending from the short central stem. Fibrils typically show triangle nodes and crotches located at regular intervals of approximately 20 to 30 microns, as seen in Figure 1 C. These nodes and crotches may have a maximum transverse dimension of 3 to 5 times that of the fibrils themselves. The crotches and triangle nodes (Figure 1 C) maybe so large that they hold in place the crossing fibrils that happen to make contact with each other under compression force providing a valuable feature of recoverable loftiness.

Furthermore, triangle nodes and crotches located on the fibrils at regular intervals of approximately 20 to 30 microns, have been associated with down's unique recovery of loft after compression, which is an important factor in the high warmth to weight ratio that makes it so suited to thermal insulation. Other fibres commonly used for insulation have considerably larger fibre diameters and therefore present less of a challenge to contain within a textile medium (table below; source: Bhuvenesh C. Goswami, Rajesh D. Anandjiwala, David Hall, 2004. Textile Sizing. CRC Press [ISBN 9780824750534]). Typical Diameter

Fiber (μπι)

Cotton 17

Wool 25

Cashmere 18

Mohair 28

Flax 20

Jute 15

Hemp 25

Ramie 50

The inventors have been very surprised to find that a synergy exists between the woven and nonwoven fabric layers when in contact, which results in a multi-layered fabric having a degree of resistance to feather/down penetration which is not displayed by any one of the component fabric layers individually, due to the relatively large pore sizes. Unexpectedly, the multi-layered fabric has been found to be effectual in containing down/feather according to the standard method in BS EN ISO 12131 -1 :1999 and/or EN 12131 -2:1999. It is suggested, but not asserted, that this synergy may be the result of relatively randomly arranged fibres (or filaments) of the nonwoven fabric layer obstructing, and partially occluding, open pores of the woven fabric layer and engaging, entangling or forming a frictional contact with the relatively regular structure/scaffold of the adjacent (e.g. woven) fabric such that either one helps support the other to better resist the displacement of fibres/yarns by an element of a filling material (e.g. feather shaft, barbules) attempting to pass through. It is, of course, to be understood that this principle of the invention is applicable to other types of fine natural or synthetic filling materials other than feathers/down, such as fibrous filling materials (synthetic or natural), and blends thereof. This is aided by the interaction of the nonwoven fabric layer with fibres (hairs) protruding from the yarns of the woven fabric layer. Experimental evidence is presented which supports for this suggestion.

The present invention is relevant to, but not limited to, highly porous covering material for filled articles such as (but not limited to) bedding, garments and related articles that simultaneously retains fibrous elements of filling material (e.g. down and/or feather or synthetic materials) and is characterised by air and moisture vapour permeability. Furthermore, the fabric assembly of the invention has been found to be washable in an aqueous medium using conventional domestic processes known in the art, most preferably at temperatures <100°C.

It has also been found that the high air-permeability in filled articles (e.g. clothing, bedding etc.) made from the fabric of the invention, possess a greater "springiness" or "bounce" in the sense that the filled article is better able to recover from a state of compression in which the filling is compressed, to a quiescent state of loftiness. This is because by the act of compressing a filled article, air contained within the volume of the article containing the filler material, is forced out of that volume to accommodate the compressed state of reduced volume there. Upon removal of the compressive force, a recovery of the former volume (driven by the springiness of the filler material) can only take place as and when air re-occupies the volume. This air must be drawn through the cover fabric of the article. A more breathable cover fabric allows a greater rate of throughput of such air and , therefore, a quicker recovery of the original volume. The sooner the original volume is recovered, the better the thermal insulating properties of the article will be. This has the effect of making the article feel more insulating in normal use as parts of the article (e.g . a jacket, sleeping bag or duvet) are intermittently compressed and released from compression due to normal movement of the user. In a first of its aspects, the invention may provide a multi-layered fabric including a first layer comprising a woven or knitted fabric having an optical porosity of between 0.06% and 35% , or a porosity of between 50% and 95% ; and , a second layer comprising a nonwoven fabric or web having an optical porosity of between 0.1 % and 15% , or a porosity of between 75% and 98% . The porosity of the first layer may be between 80% and 95% , or more preferably between 83% and 90% . The porosity of the second layer may be between 80% and 97% , or more preferably between 82% and 96% , or more preferably between 85% and 90%. In this way a breathable multi-layered fabric is provided in which the first, woven or knitted layer has a high porosity permitting a light-weight construction, lower cost, and higher air permeability. A second layer of nonwoven fabric provides a barrier to penetration of the first layer by parts of feathers or down . The multi-layered fabric may serve as an outer layer of e.g . an article of clothing or bedding containing feathers and/or down or even man-made filamentary insulating materials. The application of the multi-layered fabric is not only in garments or the like, but in any application (domestic or industrial) where it is necessary to contain a filamentary filling (natural or synthetic) without incurring (or at least reducing the occurrence of) condensation or overheating . An industrial example would be for retaining filamentary filtering materials in the presence of significant temperature and/or humidity gradients such as in industrial cooling processes/apparatus or the like.

Herein, references to "woven" and "knitted" fabric may include a reference to a fabric comprising a structure including interlaced or intermeshed yarns, threads or fibres. It is noted that the industry reference book: "Textile Terms and Definitions" (10^th Edition, 1995), by J E Mclntyre & P N Daniels [ISBN 1 870812 77 8] defines knitting as the process of forming a fabric by intermeshing of loops of yarn, and defines weaving as the action of producing a fabric by the interlacing of warp and weft threads.

The porosity of a fabric may be calculated by measuring the total volume of a fabric and the total volume of fibres in the fabric. The total volume of a fabric sample may be determined by multiplying the area (A) of the fabric sample by the measured thickness (7) of the fabric sample. The total volume of the constituent fibres of a fabric sample may be determined by dividing the density (D) of the constituent fibres of the fabric by the measured mass (1/1/) of the fabric sample. Porosity may be calculated based on the following formula:

Where P = porosity (%); A = area of the sample (m²); 1/1/= mass of the sample (kg);

7 = thickness of the sample (m); D = density of constituent fibre (kg/m³). Optical porosity characterises the extent to which pores in the fabric are visually obstructed by yarns, filaments or fibres when viewed in light reflected or transmitted from one side of the fabric. This may be determined using a digital imaging system using e.g. a CCD camera or other digital camera. The resulting image data comprises "void pixels" that correspond to the open pores (the void fraction) and "solid pixels" that correspond to the yarns, fibres or filaments (the solid fraction) in the same two-dimensional image. Optical porosity P (%) can then be defined as:

^ voidpixels

= 100 x

^ (voidpixels + solidpixels) Commonly available digital image processing software such as Image Pro-Plus (Media Cybernetics), or other software packages, can be used to perform optical porosity measurements. The terms "void pixels" and "solid pixels" preferably refer, respectively, to those pixels within an image of a fabric that are deemed to wholly or predominantly contain a part of a pore/void ("void pixel") or wholly or predominantly contain a part of a yarn, fibre, filament or solid fraction ("solid pixel").

In preferred embodiments a pixel value "X" (typically between the two extremes of 0 and 255) of a given image pixel within an image of a fabric is referred to a threshold pixel value " i_hres_hoi_d" to differentiate between "void pixels" and "solid pixels" such that:

For images captured using reflected light (e.g. front illumination of the sample, or "dark-field" illumination):

If X < X_Thres_hoi_d then the pixel is deemed a "void pixel", and;

If X > X_Thres_hoi_d then the pixel is deemed a "solid pixel". For images captured using transmitted light (e.g. back illumination through the sample):

If X > X_Threshoid then the pixel is deemed a "void pixel", and;

If X < X_Threshoid then the pixel is deemed a "solid pixel".

The threshold value X_Threshoid may be a pixel value of 75, for example, in a digital imaging device arranged to provide pixel values between the two extreme values of 0 (zero) and 255, inclusive. More generally, the threshold pixel value may be about 1/3 of the upper extreme pixel value at which the imaging device operates (e.g. 255). This has been found to be effective and reliable.

Settings on a digital imaging device (e.g. camera) are preferably selected such that the sensor chip (e.g. CCD, CMOS) of the digital imaging device is able to operate within its "linear" region in which pixels values of pixels within the sensor chip are proportional to the amount of image- bearing light they receive, thereby avoiding underexposure or overexposure in the image. This may be achieved by the appropriate settings for digital imaging device (e.g. using camera control software) such as "gain", "gamma" and "exposure time" for a given illumination situation, as would be readily apparent to the skilled person. Preferably, substantially no saturation of pixel values occurs within the pixel values of the image recorded by the digital image device. Of course, it is most preferable that the image being recorded is substantially in- focus upon the sensor chip such that the image recorded by the digital imaging device is a substantially focussed image. The image may be an image generated by an electron microscope (e.g. Scanning Electron Microscope) or may be an image generated by an optical microscope using forward illumination ("dark field"). In either case, the result is that the solid fraction of the illuminated fabric, whether illuminated by electrons or by photons, is generally brighter than the void fraction/pores of the illuminated fabric, within the captured image of the illuminated fabric. Illuminating the sample in this way with light/electrons that will not be directly collected by the imaging system, and thus will not form part of the image, produces the appearance of a dark, almost black, background with bright objects on it.

A magnification setting of x500 has been found to be suitable for image capture e.g. when using an electron microscope, particularly when imaging the fabric of the second layer. A magnification setting of between x5 and x200 (e.g. x8) has been found to be suitable for image capture particularly when imaging the fabric of the first layer.

Optical porosity differs from volume or mass based porosity measurements in that it only characterises inter-fibre pores that extend from one side of the fabric to the other. The reduction of these through-pores, particularly those with pore diameters greater than 5 μηι is a key requirement in the retention of down and feather filling materials. Thus, the invention may provide a multi-layered fabric including a first layer comprising a woven or knitted fabric having an optical porosity exceeding 0.06% and less than 35%, preferably between 0.5% and 30% and a second layer comprising a nonwoven fabric or web preferably with an optical porosity that exceeds 0.1 % and is less than 15%, preferably from 0.2% to 1 1 %, or even more preferably from 0.2% to 8%, or yet more preferably from 0.2% to 6%.

The terms "nonwoven fabric" or "nonwoven web" may be defined as in ISO standard 9092 and CEN EN 29092 and/or may be taken to include a reference to a web having a structure of individual fibres, filaments or threads which are interlaid in for example, a randomly distributed, irregular or otherwise non-periodic manner. Nonwoven fabrics or webs may be formed from any one of a number of different processes such as will be readily apparent to the skilled person. For example, a meltblowing processes, a spunbonding processes, or a bonded carded web process are all examples known in the art.

The second layer preferably includes fibres of plastics and/or polymer material, which comprise one or more of: spunbond, meltblown, electrospun or centrifugally spun fibres. The latter may also be referred to as forcespun fibres. The plastics and/or polymer material is preferably a thermoplastic material, such as a thermoplastic polymer material.

The term "meltblown fibres" includes a reference to fibres or filaments formed by extruding molten plastic (e.g. thermoplastic) materials through a number of fine, usually circular, die capillaries as molten filaments into a high velocity, usually heated, gas (e.g. air) stream which attenuates the filaments of molten plastic material to reduce their diameter. Thereafter, the meltblown fibres may be transported by the high velocity gas stream and deposited on a collecting surface to form a web of randomly distributed meltblown fibres. Such a process is disclosed, for example, in patent no. US3849241 . The term "spunbond fibres" includes a reference to fibres formed by extruding molten plastics (e.g. thermoplastic) material as filaments from a number of fine, usually circular capillaries of a spinnerette with a diameter similar to the extruded filaments then being rapidly reduced in a manner such as is described, for example, in patent no. US4340563 or patent no. US3692618. The term "electrospun fibres" includes a reference to fibres formed by a process of electrspinning. Examples are described in: "A review on polymer nanofibres by electrospinning and their applications in nanocomposites"; by Z.-M. Huang et a/. , Composites Science and Technology 63 (2003) 2223-2253. The term "polymer" may include, but is not limited to, homopolymers, copolymers, terpolymers, etc. and blends and modifications thereof, and includes a reference to all possible geometrical configurations and symmetries of the material. The second layer may itself be a multi-layer of nonwoven fabric sub-layers. The second layer may comprise a first sub-layer and a second sub-layer arranged adjacent to the first sub-layer. The second sub-layer may comprise fibres/filaments, which have an average diameter that is less than the average diameter of the fibres/filaments of the first sub-layer. For example, the second layer may include a layer (e.g. a first sub-layer) comprising spunbond fibres and a layer (e.g. a second sub-layer) comprising one of: meltblown fibres or electrospun fibres of forcespun fibres. In this way, the second layer may itself comprise a multi-layer, or laminate, of different nonwoven fabrics. The first sub-layer of the second layer (e.g. of spunbond fibres) may be arranged immediately adjacent to the first layer (woven/knitted fabric) such that the two make frictional contact, or are free to do so. It has been found that meltblown or electrospun fibres or forcespun fibres may generally be finer in diameter than are spunbond fibres and produce a greater number of fibres per unit volume (or solid surface volume) for a given porosity. This may be particularly effective in forming a barrier to penetration of the finer elements of filamentary filling materials such as feathers and down, and the barbules thereof, in particular. The spunbond fibres may tend to be thicker in diameter than the meltblown or electrospun fibres and have been found to provide a robust barrier against penetration by larger objects such as the quills of feathers and down. Thus, the second layer may be provided as a multi-layer of different nonwoven fabrics, which respectively serve as a barrier to different components of heterogeneous filling material (e.g. feathers and down).

The second layer may comprise a third sub-layer, as well as the second sub-layer and the first sub-layer, in which the second sub-layer is arranged intermediate the first sub-layer and the third sub-layer (e.g. arranged in a laminate structure). The intermediate second sub-layer may be arranged between the first and third sub-layers (e.g. sandwiched) and is preferably in contact with each. The intermediate sub-layer may comprise fibres/filaments, which have an average diameter which is less than the average diameter of the fibres/filaments of each of the first sub-layer or the third sub-layer. The second layer (nonwoven layer, as a whole) may include a sub-layer comprising meltblown fibres or electrospun fibres between two sub-layers which each comprise spunbond fibres. Thus, in some embodiments, the second, nonwoven layer, may comprise three sub-layers of which the intermediate sub-layer is meltblown or electrospun. This three-layer laminate has been found to be particularly effective in providing a barrier to feather/down penetration preferably when the weight of the intermediate second sub-layer as a proportion of the entire second layer is above a desired value of about 10%. It is suggested, but not asserted, that, in use, the first and third outer sub-layers serve to anchor or restrain a feather quill and thereby restrict its ability to move (e.g. "wiggle") relative to the intermediate sub-layer which is effective as a barrier to finer elements of the feather (e.g. barbules) extending from the quill. This more effectively traps, entangles or "catches" feathers and down. The second layer preferably includes meltblown fibres or electrospun or forcespun fibres which comprise between 10% and 50% of the second layer by weight, or more preferably between 13% and 50%, or yet more preferably between 15% and 50% of the second layer by weight. These values provide for sufficient meltblown or electrospun or forcespun fibres/filaments per unit volume for providing a barrier to elements of feather or down.

The second layer preferably has an air permeability of between 25cm³/cm²/s and 120cm³/cm²/s. Air permeability may be determined according to the test method of BS EN ISO 9237:1995; 5cm²test area (deviations from this standard are noted in appendix A).

The fibres of the second layer, preferably such as a said first or third sub-layer thereof, have an average fibre diameter, which is from Ι Ομηι to 25μηι, and more preferably from 18μηι to 19μηι, preferably with a standard deviation from Ο.δμηι to 2.5μηι, most preferably about 1.δμηι to 1 .8 μηι. The fibres of the second layer, preferably such as a said second sub-layer thereof, have an average fibre diameter which is less than 9μηι, and more preferably less than 5μηι, and yet more preferably no greater than about 3.6μηι, preferably with standard deviation from 0.3μηι to Ο.δμηι, most preferably about Ο.δμηι. The average inter-fibre pore diameter of the second layer is preferably between 9μηι and 12μηι. The minimum pore size may be in the range 3.5μηι to 4.5μηι, and the maximum pore size may be in the range 30μηι to 55μηι.

The second layer preferably has a fabric area density of between 10gm^"2 and 10Ogm^"2, or more preferably, between 15gm^"2 and 55gm^"2.

Where the second layer comprises sub-layers, as described above, the sub-layers are preferably thermally bonded to connect them together as one laminate layer. To ensure the fibrous network is substantially retained, the layers are preferably point-bonded, i.e. the thermal bonds may be spatially separated and distributed. Alternatively, the sub-layers may be attached together by means of mechanical bonding, preferably hydroentangling using methods known in the art. The first and second layers may either be connected together continuously as in the form of laminated structure or discontinuously, such that the distance between each layer is variable and the two layers are connected only at certain locations arranged randomly or periodically.

The polymer composition is preferably composed of a hydrophobic, thermoplastic polymer such as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), coPET, polyamide (PA), CoPA, polylactic acid (PLA), polybutylene terephthalate (PBT), polytrimefhyiene terephthalate (PTT) or combinations thereof. The first layer preferably comprises staple fibre yarns, which are woven (e.g. interlaced) or knitted (e.g. intermeshed) together. Preferably, one, some or substantially all the yarns of the first layer are hairy. Yarn hairiness characterises the frequency of hairs (fibres) protruding above the surface of a textile yarn. Hairs consist of protruding fibres, looped fibres and loosely wrapped fibres. Especially, in case of staple spun yarns, since multiple fibres are bound in a single yarn, fibres tend to protrude beyond the main body of the yarn even though the yarn is twisted or otherwise frictionally bound. A well known measure of yarn hairiness is the so-called USTER Hairiness Index (H) formulated by Uster Technologies (www.uster.com) and widely accepted within the art. This defines hairiness as the total (cumulative) length, measured in centimetres, of protruding fibres/hairs originating from one centimetre of the observed yarn, divided by 1 cm. The hairiness index (H) is therefore dimensionless (i.e. cm/cm). The measured hair length are the lengths of the hairs projected onto a 2-dimensional (2D) plane within which the 1 cm yarn length resides (i.e. parallel to the plane), The 2D plane may be the plane of a 2D image of the hairy yarn in question if hair lengths are measured via image inspection/processing, or may be the 2D plane of an array of photoelectric sensors arranged to detect the quantity of light scattered to them by hairs of the yarn. Indeed, there are several ways in which the measurement of cumulative hair length may be performed in order to arrive at the Hairiness Index (H), as will be readily appreciated by the skilled person, though all employ the same definition of H.

It has been found that an effective methodology for evaluating the Hairiness Index (H) of a yarn is to make the evaluation over a 0.5cm evaluation length by visual inspection and manual image processing of a 0.5cm evaluation length within an image of a sample yarn taken at a magnification of about x40 (optically or via an SEM). The total (cumulative) length, measured in centimetres, of protruding fibres/hairs originating from the 0.5cm evaluation length of the observed yarn is then simply doubled to represent the estimated total (cumulative) length over a 1 cm evaluation length of the same yarn, in accordance with the USTER Hairiness Index (H) definition. This smaller initial evaluation length allows for higher magnifications and easier evaluation of the cumulative hair length over that 0.5cm, and has been found to be produce hairiness indices (when doubled as described above) consistent with those obtained when using a full 1 cm evaluation length within the image. Images are preferably taken of a free yarn length not under tension. In this context, the hairiness index represents double the cumulative length of hairs (in cm) measured over an initial evaluation length of the fabric or yarn of 0.5 cm herein, divided by 1 cm.

In preferred methodologies of calculating the USTER Hairiness Index (H) , images of the yarns may be taken and calibrated with image analysis software using the procedure stated in the Image Calibration section of Appendix B. Following calibration, the length of a hair protruding from the central yarn body can be measured from the point (referred to herein as the "stem") at which it is seen within the image to detach (e.g. protrude, loop out from or otherwise become visibly salient or stand proud) from the central yarn body. The length of the hair may be measured from its "stem" to its terminal end. The terminal end may be the physical end of the hair visible within the image, or the point at which it re-enters the central yarn body (i.e. another "stem"). For example, using the software referred to in Appendix B, one may use the "line lengths" function available under the tabs 'Measure'→ 'Measurements'. When using light microscopy and manual measurements of yarn hairiness through image analysis software the magnification may preferably be set at the largest possible while still capturing an evaluation length (e.g. 5mm length) of yarn to give the best resolution of visible hairs. Most preferably, dark field microscopy may be used, with light sources (e.g. twin single spot LEDs at 10cm) illuminating the yarn specimen, to reduce the translucency of fibres and the chance of missing them. If using alternative software that has been similarly calibrated a 'trace' function, such as would be readily apparent and available to the skilled person, should record the same information. Indeed, manual measurement of cumulative hair lengths taken by inspection of a printed paper copy of the image may be done if necessary. The hairiness measurements herein are the doubled cumulative total length of all hairs protruding from the central yarn body within a 0.5cm length of yarn, divided by 1 cm. Only the cumulative length of the hairs originating within this 0.5cm frame are considered. The full lengths of such hairs are included (i.e. to their ends) even if the end in question falls outside of the chosen evaluation length provided that their "stem" is within the evaluation length.

The hairiness index (H) of the fabric of the first layer is preferably between 2 (e.g. 10 mm cumulative hair length over a 0.5cm evaluation length, doubled) and 20 (e.g. 100 mm cumulative hair length over a 0.5cm evaluation length, doubled), when measured over a 1 cm evaluation length, or over a 0.5cm evaluation length doubled as described above. More preferably, the hairiness index (H) is between 4 and 12 (e.g. 20 mm and 60 mm cumulative hair length over a 0.5cm evaluation length, doubled), when measured over a 1 cm evaluation length, or over a 0.5cm evaluation length doubled as described above. The hairiness index (H) may be an average value of a plurality of hairiness indices for the first layer, e.g. measurements are taken at a plurality (e.g. many) different locations and evaluation lengths, across the fabric.

The cover factor of the first layer is preferably less than 40, preferably between 15 and 40, and more preferably between 25 and 35. The cover factor of the factor was calculated as follows separately for both the warp and the weft directions in the fabric:

Threads _ per _ Inch

CoverFactor

The overall cover factor of the fabric is the sum of the warp and weft cover factors. The cover factor is a measure of the tightness of the woven fabric structure. A lower cover factor indicates a more open fabric. It is also possible for the hairiness of the woven fabric of the first layer to increase as its cover factor value falls due to reduced yarn twist, reduced axial fibre alignment or mechanical surface finishing treatments, such as raising, that produce a pile on the fabric surface. An increase in yarn hairiness enables a stronger synergistic interaction as described above, whereby protruding fibres of the first layer engage with the filaments or fibres of the second layer to enhance the frictional interference between the two layers. The average inter-yarn pore diameter of the first layer is preferably between 5μηι and δθθμηι. These values may be determined according to any suitable method known in the art. An example is given below.

The first layer preferably has a fabric area density of between 20gm^"2 and 120gm^"2. The first layer preferably has an air permeability of between 3cm³/cm²/s and 250cm³/cm²/s. Air permeability may be determined according to the well-known test method of or BS EN ISO 9237:1995; 5cm² test area).

The structure of the first (outer) layer alone is preferably a woven fabric or a warp knitted fabric characterised with a relatively high mean inter-yarn pore diameter (e.g. such as determined by the image analysis procedure given below) such that, alone, it is insufficient to prevent penetration of tendrils or barbules of feather, down or admixtures of both. The first layer may comprise interlaced or intermeshed yarns composed of naturally occurring fibre materials such as cotton, flax (linen), ramie, hemp, bamboo, wool and silk (or blends thereof as well as blends with staple man-made fibres). It may be constructed from regenerated cellulose man-made fibre or filaments such as Tencel (lyocell), viscose, cellulose acetate and triacetate, polynosic rayon and cuprammonium rayon.

The invention may provide an article comprising down and/or feathers contained within a container formed from a multi-layered fabric as described above. For example, the article may be an article of clothing or bedding. Examples include duvets, quilts, comforters, bed sheets, pillows, sleeping bags, hats, gloves, jackets, coats, trousers (e.g. skiing trousers) and tops. The invention may also be applied to articles that are not bedding or clothing, but are used for insulation purposes where breathability, light-weight and/or rapidity of drying are important. Examples include light-weight lagging for pipes, aircraft/vehicular insulation and light-weight temporary shelters (e.g. bivouacs ("bivvy") or ients).

The invention may provide an article comprising multi-layered fabric as described above, and including a first portion of a said fabric ultrasonically welded to a second portion of a said fabric wherein the second layer of the first portion is in direct contact with the second layer of the second portion where welded. This has been found to provide a strong bond.

In a second aspect, the invention may provide a method of manufacturing a multi-layered fabric comprising, providing a first layer comprising a woven or knitted fabric having an optical porosity of between 0.06% and 35%, or a porosity of between 50% and 95%; and, a second layer comprising a nonwoven fabric or web having an optical porosity of between 0.1 % and 15%, or a porosity of between 75% and 98%; and, arranging the second layer and the first layer together to provide a multi-layer fabric. The porosity of the first layer may be between 80% and 95%, or more preferably between 83% and 90%. The porosity of the second layer may be between 80% and 97%, or more preferably between 82% and 96%, or more preferably between 85% and 90%.

The second layer preferably includes fibres of plastics and/or polymer material, which comprise one or more of: spunbond, meltblown or electrospun or forcespun fibres. The plastics and/or polymer material is preferably a thermoplastic material, such as a thermoplastic polymer material.

The method may include arranging the first layer directly in contact with the second layer.

The method may include attaching the second layer to the first layer. The method may include forming the second layer to include a sub-layer comprising spunbond fibres and a sub-layer comprising one of: meltblown fibres or electrospun fibres.

The method may include forming the second layer to include a sub-layer comprising meltblown fibres or electrospun fibres arranged between two further sub-layers which each comprise spunbond fibres. Where the second layer comprises sub-layers, as described above, the sub-layers method may include thermally bonding fibres of the sub-layers to connect them together as one laminate layer. Alternatively, or additionally, the method may include connecting the sublayers together by means of hydro-entangling using methods known in the art.

The invention is not limited to the use of a two-layered construction (e.g. a woven/knitted outer layer plus a non-woven inner layer). Embodiments of the invention may comprise multiple separate, but adjacent inner layers of non-woven material. Embodiments of the invention may also comprise multiple adjacent inner layers of nonwoven material that have been assembled to form one unified layer. For example, it is possible for a meltblown fibre layer to be made up of one or more individual layers of meltblown (M) fibres sandwiched between two or more spunbond layers (S). Examples include, but are not limited to, the following configuration/layering structure: SMS, SMMS, SMMMS, SSMMSS, SSMMS.

Versions of our invention comprising a second layer with a fabric area density between 40 and 50g/m² demonstrated substantially complete resistance to fine fibre percolation when tested with five 40°C wash and 65°C dry cycles (in accordance with British Standard BS EN ISO 6330). It is suggested, but not asserted, that densities upwards of 40g/m² are desirable to withstand the mechanical irritation of repeated washing procedures.

These weights also support the use of lower quality fillings, specifically down and feather which has higher ratios of feather to down. A 90:10 down and feather mix from Hungarian geese was selected for the above fine fibre percolation tests (unless otherwise stated). At lower ratios of down to feather - such as commercially available 80:20 there is an increased challenge in retaining the filling without using one densely woven cambric material due to the increased amount of quills in the mix that have the ability to damage lightweight (e.g. < 35gsm) aforesaid second layers. Additionally the lack of aforementioned triangular nodes or crotches on feathers and quills reduces the opportunity to mechanically interlock with the filaments in the second layer, so mixes comprising high quantities of feather in relation to down are preferably enclosed within assemblies featuring aforesaid second layers with fabric area densities of between 35g/m² and 55g/m². In the absence of down/feather ratio information lower quality fillings can also be assumed as those with a low fill power for their weight compared with other commercially available fillings. While there is no internationally recognised test procedure for measuring "fill power", the so called "Lorch test" is an accepted methodology in the United Kingdom for measuring this quantity. All tests must use the same conditioning procedure, sample weights and measuring equipment and materials are only comparable to samples tested in the same batch. Typically fill powers of down mixes used in bedding is upwards of 400 cubic centimetres per gram, below this fill quality (in terms of loftiness and ability to trap still air) degrades progressively. In some embodiments of the invention, a combination comprising a lightweight cotton said first layer (e.g. 133x72, 40ne) with a e.g. a 35g/m² said second layer also demonstrated substantially 100% allergen barrier efficacy when tested in accordance with the SP304 "Allergen barrier with Airflow test at Airmid Healthgroup laboratories. In doing so, the embodiment of the invention substantially prevented the through-movement of allergen particles such as "fel d 1 " particles which are less than Ι Ομηι in diameter and dust mite faecal pellets, "derp 1 " which ranges between Ι Ομηι and 40μηι. The term "Fel d 1 " refers to the primary allergenic protein from cats, and "Derp 1 " is the primary allergenic protein from European dust mites. The dust mite itself has a size of 250μηι to 300μηι. By contrast, current cambric fabrics used in down and feather bedding demonstrated 99% allergen barrier efficacy in the same test, failing to prevent 1 % of small respirable particles that can cause asthma and allergies. It is suggested, but not asserted, that because of the fine fibre matrix of the aforesaid second layer, and the mechanical support provided by the aforesaid first layer, a highly tortuous path is presented to allergen particles to prevent their transference in much the same way as preventing down permeations.

The invention may provide a method of manufacturing an article comprising providing multi- layered fabric as described above, and ultrasonically welding a first portion of a said fabric to a second portion of a said fabric wherein the second layer of the first portion is in direct contact with the second layer of the second portion where welded. This is a simple and quicker way to form a strong bond, as compared to sewing.

It has been found that despite common perceptions, the keratin from feathers and down is not the primary source of allergies in the bedroom. Very few people are actually allergic to feather and down, but the majority have their symptoms aggravated by dust mite allergens. The most effective strategy to prevent these allergens accumulating in bedding is to make the bedding (e.g. duvet/pillow) an undesirable or uninhabitable environment for dust mites. It has been found that bedding, or other articles, made according to the fabric in preferred embodiments of the invention is very effective at achieving this result. This is achieved for the following reasons.

Mites are prevented from passing through the fabric and entering the inner filling of the bedding/article contained by the fabric. Dust mites are around 400μηι long, 250μηι wide, and their larvae can be somewhat smaller. The second layer of the fabric (e.g. an SMS layer) may have a mean pore size (e.g. around 10μηι), which much too small for the mites and their lavae to get through. Also, asthma/allergy triggering "Der p1 ", "Der p2", "Fel d1 " particles (see above) can range anywhere between 0.2- 40μηι in diameter. Despite a mean pore size within the second layer of fabric which may typically be greater than 0.2μηι, an allergy barrier with airflow test demonstrated that the second layer materials (e.g. a mean pore size around 10μηι), blocked 100% of these particles from passing through. Furthermore, mites like temperatures between 17-32°C, relatively humid conditions (>55% RH) and dark. Environments outside these ranges are unfavourable, and mite numbers will be small or not present. By providing a far more breathable fabric, articles made using a fabric of preferred embodiments of the invention create far less humid conditions within the filling of bedding and conditions are unfavourable to mites. As a result of the enhanced breathability of the fabric, any increases in humidity after a night's sleep (sweat/breath) will be lost quickly to the environment when the user leaves the bed in the morning. Likewise the duvet will drop back to room temperature quickly, e.g. about 16°C.

Normal cambric weave cover fabric is usually dust mite proof as a result of having a weave structure sufficiently dense to make it down proof. However the construction of an item of bedding, such as a pillow or duvet, or other article, includes seams which are not effective barriers to mites and larvae. This is because the needles used to produce/sew a seam punch large holes through the cover fabric, sufficient to admit mites into the filler material held within the cover. Also any increases in humidity/temperature after a night's sleep are lost only slowly to the environment (cambric's low air permeability) making it more favourable for dust mites to live in the filling once they get in. In order to isolate or seal (preferably hermetically) a filling material (e.g. down and feather) from such seams, the invention may provide an article of bedding or clothing comprising a fabric according to the invention in its first aspect, which defines a container part for containing a filling material and having one or more seams sewn along the fabric which join together two opposing parts of the fabric, and wherein the seam is isolated from the container part by a substantially continuous weld between the respective second layers of the opposing parts of the fabric. The second layer of the fabric may preferably be a synthetic polymer material susceptible to ultrasonic welding, and the aforesaid welds may be ultrasonic welds. Ultrasonic welding uses high frequency vibrations to generate frictional heat between molecules, which are then pressed together and bonded with a pressurised welding foot. There are no needle holes through which the dust mite can travel. However, ultrasonic welding will usually not join cotton to cotton, but is very effective at joining a polymer material to another polymer material, such as preferably employed in the aforesaid second layer of the fabric. An example is "SMS to SMS". As cotton is a luxurious cover material, and more breathable than polyester, it is preferable to use cotton as the first layer in the fabric, and to incorporate some sewing/seams in order to help hold the article (e.g. duvet) together. However, by isolating the sewing from the container part using welds, one may isolate any sewn holes from areas of filling material such as down and feather ultimately placed in the container part.

Preferably, one, some or all of the boundaries/edges of the container part are defined by one or a plurality of said welds thereby to define the shape of the container part. One, some or each of the sewn seams may each be contained collectively or individually/separately between two respective said welds extending along substantially the whole length of the sewn seam. The two said welds may be parallel to each other and may also be parallel to the sewn seam they isolate. Preferably one some or each sewn seam is wholly surrounded by a said weld or welds. The weld or welds may be substantially linear. A plurality of welds may cross over each other in such a way as to collectively enclose a region of the fabric which is isolated from the container part and which contains a sewn seam.

There now follows a non-limiting embodiment of the invention for the purposes of illustration, with reference to the accompanying drawings of which: Figure 1A, 1 B and 1 C show an electron microscope images of a main shaft and tendrils of a feather (Fig.l A), and down (Fig.l B) possessing triangle nodes and crotches (Fig.l C) upon a fibril, used as insulation filling in an item or bedding or clothing;

Figure 2 shows a scanning electron microscope image of a quill tip of the feather of Figure 1 ;

Figure 3 shows a scanning electron microscope image of down micro-structure including barbules;

Figure 4 shows a scanning electron microscope image of a woven cotton fabric with a tightly- woven, low-porosity, satin weave pattern that is down-proof;

Figure 5 shows an electron microscope image of a porous cotton fabric with a loosely woven plain weave pattern, which is not down-proof; Figure 6 shows an electron microscope image of a nonwoven fabric comprising a layer of melt- blown thermoplastic polymer filaments (thinner) sandwiched between two layers of spunbond thermoplastic polymer filaments (thicker), with a porous structure, which is not down-proof; Figure 7 shows a scanning electron microscope image of a nonwoven fabric of Figure 6 at lower magnification comprising an array of separate thermal bonding (melted) points, which bond together the three layers of thermoplastic polymer filaments; Figure 8 schematically shows an article covered by a fabric according to an embodiment of the invention including a cut-away part showing component layers of as multi-layer fabric structure;

Figure 9 schematically shows a duvet comprising a fabric according to Figure 8; Figure 10 shows a cross-sectional view of the duvet of Figure 9;

Figure 1 1 schematically shows a perspective, cut-away view of the duvet of figures 9 and 10;

Figure 12 shows a pillow comprising a fabric according to Figure 8;

Figure 13 schematically shows a cross-sectional view of the pillow of Figure 12;

Figure 14 shows a sleeping bag comprising a fabric according to Figure 8;

Figure 15 shows a cross-sectional view of the sleeping bag of Figure 14;

Figure 16 shows a down jacket comprising a fabric according to Figure 8;

Figure 17 shows a cross-sectional view of the down jacket of Figure 16; Figure 18 schematically shows an apparatus for manufacturing a nonwoven fabric such as shown in Figure 6;

Figure 19 schematically shows a cross-sectional view of a multi-layer fabric comprising the nonwoven fabric of Figure 18;

Figure 20 shows a perspective view of the nonwoven fabric of Figure 18;

Figures 21 A and 21 B show graphs of peak penetration forces (Graph 1), and breaking strength (Graph 2) in tests conducted upon fabrics such as shown in Figure 19;

Figures 22 to 25 show an ultrasonic weld described in Appendix F; Figures 26 to 38 schematically illustrate successive stages in the manufacture of an anti- allergen, hermetically sealed article according to an exemplary application of the fabric of an embodiment of the invention; Figure 39 shows an optical image of the hollowfibre filling together with e reference scale bar (250 microns);

Figure 40 (left) shows 35gsm SMS fabric SEM image taken at 500x magnification, and Figure 40 (right) shows the result of applying a mask to an area of interest (AOI) showing areas occluded by fibres (black) against optical pores (white);

Figure 41 shows a diagram of an apparatus for determining Coefficients of Friction.

In the drawings, like items are assigned like reference symbols.

Referring to Figures 1 , 2 and 3 there are shown scanning electron microscope images of elements of feathers used as insulation filling in items of clothing or bedding. Figure 1 shows the main stem and filaments of a feather, while Figure 2 shows its quill/shaft tip. Figure 3 shows the barbules present in filaments of feathers and down. These filaments and quills are prone to penetrate the covering fabric of the item (e.g. clothing, duvet or pillow) encasing them unless steps are taken to render the covering fabric resistant to such penetration ("down- proof). Figure 4 shows a scanning electron microscope image of a woven cotton fabric with a tightly-woven, low-porosity, satin weave construction, which is designed to be down-proof (i.e. resistant to the penetration of quills or other parts of the feather or down). It has low air permeability and vapour breathability and is relatively heavy, stiff and expensive to use in bedding or clothing items as a result of the fabric density.

Figure 5 shows a scanning electron microscope image of a porous cotton fabric with a loosely woven plain weave construction that is not down-proof, but which is more air permeable and vapour breathable than is the fabric of Figure 4. It is lighter and cheaper to use in bedding or clothing items as a result. Note that the yarns of the fabric of Figure 5 are substantially hairier than those of the fabric of Figure 4.

Figure 6 shows a scanning electron microscope image of a nonwoven fabric comprising a layer of melt-blown (M) thermoplastic polymer filaments (thinner) sandwiched between two layers of spunbond (S) thermoplastic polymer filaments (thicker), with a porous structure, which is not down-proof. The SMS nonwoven fabric is light and has a high air permeability and moisture vapour breathability. The filaments of the spunbond (S) components are located in the foreground and at the rear of the fabric, with the meltblown (M) component/s visible between them.

Figure 18 schematically shows a method and apparatus for manufacturing the SMS nonwoven fabric of Figure 6. Spunbond fibres of a lower sub-layer of the nonwoven fabric are extruded as filaments of molten thermoplastic material from a number of fine, circular capillaries of a spinnerette (18). The filaments are deposited on a collecting conveyor surface (24) to form a lower web (21) of approximately randomly distributed spunbond fibres. In practice, it is not unusual for the filaments to be arranged with slight preferential orientation in the machine direction. The meltblown fibres (M) of the intermediate sub-layer of the SMS fabric are extruded as molten filaments of thermoplastic materiall, through a number of fine, circular, die capillaries (19) into a high velocity, heated, gas stream (not shown) which attenuates the filaments reduce their diameter. The meltblown filaments (22) are attenuated by the high velocity gas stream and deposited on the collecting conveyor surface (24) to form a web of approximately randomly disbursed meltblown fibres on top of the web of spunbond fibres (21 ). A second and upper layer of spunbond fibres (23) is then deposited on top of the intermediate web of meltblown fibres by a second spinnerette (20). A three-layer nonwoven fabric is thereby manufactured and is thermally bonded between a pair of heated calender rollers (25). The upper roller is embossed (26) wherein projections on the surface of the roller and are brought into very close proximity to the opposing surface of the lower bonding roller (osculate) which acts in the manner of an anvil against which the three sub-layers (SMS) of the nonwoven fabric are pressed by the bonding nodes, which are heated to cause melting of the thermoplastic filaments of the pressed SMS layers to cause them to bond together there when the thermoplastic filaments re-solidify. A pattern of separate and discrete bond points (27) are thereby formed in a regular configuration across the final nonwoven fabric (28) which fix together its three component sub-layers (SMS). Figure 20 schematically shows such a final nonwoven fabric. It is noted that an electrospun (E) intermediate sub-layer (22) comprising thermoplastic polymer may be formed in place of the meltbown sub-layer. Figure 7 shows a scanning electron microscope image of the nonwoven fabric of Figure 6 at lower magnification. This shows an array of separate heat-bonding (melting) points, which bond together the three layers of thermoplastic polymer filaments.

Figure 19 schematically shows a cross-sectional view of a multi-layer fabric (29) comprising the nonwoven fabric of Figure 6, 7 or 18 or 20, combined with a woven fabric such as is shown in Figure 5. Figure 8 schematically shows a fabric of the type shown in Figure 19 including a cut-away part showing component outer woven layer (1) of a multi-layer fabric structure, overlying an inner feather-retaining layer (2) of nonwoven fabric for retaining the feathers of an insulating feather filling material (3). Example 1

A multi-layer fabric was constructed as follows. The first layer was composed of 100% cotton of area density (basis weight) 80 gm ². The fabric was woven and comprised twisted staple yarns. Pore diameters in the fabric ranged from 6.41 μηι to 167.06μηι (as determined using a PMI tester: see Appendix C). The air permeability of the fabric was 250cn 7cm²/sec. The second layer consisted of a layered structure comprising an intermediate sub-layer of meltblown thermoplastic polypropylene fibres (M) sandwiched between two outer sub-layers of spunbond thermoplastic polypropylene fibres (S). The three sub-layers (SMS) of this structure were connected together at discrete locations by thermal point bonding of the SMS fabric. The SMS fabric contained a melt-blown layer that represented 20% by weight of the entire weight of the SMS layer construction. A duvet assembly (5) schematically shown in Figure 9, was made by bringing the first and second layers into contact, folded to make a 210mm by 140mm rectangle then sewn by sewing machine around three edges. The final article was manufactured by injecting a 30g mixture of loose filling material (3) composed of 90% goose down and 10% feathers into the assembly and then sealing the article, again by sewing. This construction resulted in the outer cover schematically illustrated in figure 10 and 1 1 , composed of the first layer (1) and the second (SMS) layer (2) 'free-floating' above the feather/down filling material (3) apart from at the sewn seams (4).

The down/feather penetration resistance of an article constructed according to BS EN ISO 12131 -1 : 1999 was then evaluated in line with the procedure provided. At 2700 revolutions and no penetration of the combined layers by the enclosed down/feather mixture was observed. An additional benefit of using this construction is a reduction in outer material basis weight; 100 gm^"2 (80% of which is the first layer of woven fabric) as opposed to 1 16 g m^"2 of a typical current woven fabric (e.g. Cambric). The reduction in weight also reduces overall material consumption costs.

Example 2

Using the same test procedure and British Standard methods outlined in Example 1 , a full factorial experiment was conducted on three different types of first layer when combined in conjunction with one of three different second layers. Abbreviated specifications for each material are provided below. First Layer 01 : area density 80g/m²; 600μηι layer thickness; 27.96% optical porosity;

91 .4% porosity.

First Layer 02: area density 92g/m²; 400μηι layer thickness; 16.89% optical porosity;

85.81 % porosity.

First Layer 03: area density 1 16g/m²; 400μηι layer thickness; 0.06% optical porosity;

81 .29% porosity.

Second Layer R1 : 13.5% meltblown (MB) component, by weight; area density 15g/m²;

400μηι layer thickness; 10.63% optical porosity; 95% porosity.

Second Layer R2: 20% MB component, by weight; area density 20g/m²; 400μηι layer thickness; 4.91 % optical porosity; 88% porosity.

Second Layer R3: 22.5% MB component, by weight; area density 35 g/m², 400μηι layer thickness; 0.20% optical porosity; 83% porosity.

Properties of these six layers are given in Table 1A. The column heading "MVT" refers to moisture vapour transmission rate. The pore porometry values refer to pore diameter statistics. The down/feather retention results with different combinations of outer and retainer layers are given in Table 1 B. These data were obtained following testing according to BS EN ISO 12131 - 1 :1999, and the pass/fail criteria obtained from BS EN 13186:2004 "Feather and down - Specification for feather and down filled bedding articles". According to this standard, below five feather/down penetrations is "excellent", while six to fifteen penetrations is rated as "acceptable", and over fifteen is otherwise.

Table 1 B

Table 1 B indicates the number of penetrations of down/feather (over 2mm in length, according to BS EN IS012132-1 : 1999) when the specified first layers ("Outer" layers: 01 ,02,03) were used in conjunction with one of three second layers (feather "Retainer" layers: R1 ,R2,R3). Note in Table 1 B, that only one combination R1/01 resulted in a rating other than acceptable or excellent. In this case, the second layer had an area density of 15gm^"2 (gsm), comprising thermal point-bonded SMS fabric with a 13.5% by weight melt-blown component, an optical porosity of 10.63%, a minimum pore diameter of 4.25μηι and a maximum pore diameter of 51 .29μηι. This SMS fabric had an air permeability of 1 15.2cm³/cm²/sec. The woven fabric first layer was composed of 100% cotton with an area density of 80gm^"2.

The fabric comprised staple yarns. Pore diameters in the fabric ranged from 6.41 μηι to 167.06μηι (as determined using a PMI tester: see Appendix C). The air permeability of the fabric was 250cn 7cm²/sec. The test sample was constructed according to BS EN ISO 12131 -1 :1999 and filled with 30g mixture of 90% goose down and 10% feathers before the assembly is sealed by means of machine sewing. There were 21 penetrations of the combined layers of primarily small feathers. The next experiment combined layers R1 with 02, which was composed of 100% cotton of area density, 92gm^"2 and comprised staple yarns. Pore diameters in the first fabric layer ranged from 2.17μηι to 77.3μηι (as determined using the PMI tester). The air permeability of the outer layer was 33.4cm³/cm²/sec. The test sample was again constructed according to BS EN IS012131 -1 :1999, and was filled with 30g mixture of 90% goose down and 10% feathers before the assembly is sealed by means of machine sewing.

There were 13 penetrations of the combined layers of primarily small feathers. This indicates, rather unpredictably, that a minimum outer layer weight, in this instance 92gm^"2 is desirable to protect lighter (less than 20gm^"2) layers of the SMS second layer from damage during the penetration test. Also noteworthy was that samples with less than a 13.5% meltblown component (by weight) in the SMS second fabric layer, but of similar construction as compared to R1 , R2 and R3, were found not to be down-proof when used in combination with a first layer according to the specifications for layers 01 or 02, given above, where the air permeability was greater than 3.50cm³/cm²/sec.

Example 3

In order to substantiate the suggestion that the first and second fabric layers work in synergy to form a barrier to feather/down penetration, the following experiment was performed. Since no standard method exists for testing the force required for a fine object, similar to a quill (diameter less than 5mm), to pass through single or dual layered fabric material, the experimental method performed is described in detail in Appendix D herein.

The structures of the first and second layers employed in this experiment were the same as specified in Example 2 given above (01 , 02, 03; R1 , R2, R3). However, penetration testing of combinations of first layers (01 , 02) and second layers (R2, R3) were selected which comprised individual fabric layers that are not considered down-proof on their own (whereas first layer type 03 is down-proof on its own - a cambric weave with low porosity and permeability). After combining a respective one of the first (outer) layers (01 or 02) with a selected one of the second (retaining) layers (R2 or R3), large increases in penetration resistance force were observed. The penetration resistance force was found to be significantly greater than the penetration resistance force possible in any one of the two component layers of the multi-layer fabric. In some instances, the penetration resistance exceeded the sum of each individual resistance. This is shown graphically in Graph 1 of Figure 21 A.

When either of the two selected second (retention) layers, R2 or R3, was combined with outer layer 2(02), the penetration force was greater than that of existing down-proof fabrics. The combination of R2 or R3 with outer layer 1 (01) came very close to that of existing, tightly woven down-proof fabrics. Down proof assemblies according to embodiments of the invention had a resistance to penetration greater than 1 1 N, often greater than 15N and some greater than 20N. Surprisingly, similar levels of elongation, (the corresponding displacement recorded to the point of break-through or rupture) in millimetres, are recorded for individual 01 , R2, R3 and combinations thereof. Combinations of 02, R2 and R3 show higher elongation before rupture than each layer individually, but less than the sum of both parts. The large increase in penetration force in the multi-layer fabric as compared to each component fabric of the multi-layer, supports the suggestion that there is frictional interaction between the component fabrics. If no synergy existed, one would expect to observe that the penetration resistance of the multi-layer fabric matches the penetration resistance of the most resistant component fabric. However, in each case shown in Graph 1 of Figure 21 A, the penetration resistance force of the multi-layer significantly exceeds the penetration resistance force of the most resistant component layer - namely, the first (outer) layer of woven fabric. In the case where the first layer 01 is combined with either of the second layers R2 and R3, the penetration resistance virtually doubles. It is suggested, but not asserted, that this may be because as the penetration element (a needle in this experiment - but, by analogy, a feather quill) pushes against the second layer towards the first layer, the filaments and fibre of the former are pushed against the fibres (to some extent projecting fibres or hairs) of the latter which causes each to grip, entangle or frictionally engage the other to a greater extent than would be the case were the penetration element absent. This gripping action allows the filaments of the second layer to more effectively resist the attempts of the penetration element to separate them to an extent otherwise sufficient to allow the penetration element to pass between the filaments and onwards through an open inter-yarn pore of the first layer. It is believed that this synergy may provide a positive feed-back whereby increased pressure from a penetration element (e.g. quill) simply increases the friction between the fibres of the first and second layers further enhancing their penetration resistance. Example 4

In order to further substantiate the suggestion that the first and second fabric layers work in synergy to form a barrier to feather/down penetration, the following experiment was performed to determine a coefficient of static friction between first and second layers of the multi-layer fabric.

Testing the coefficient of static friction between two fabrics was based on standard INDA 1ST 140.1 (95); Static and Kinetic Coefficient of Friction of Nonwoven Fabrics. Further details of the experimental method are given in Appendix E, and any deviations from this standard are indicated there.

The highest coefficient of static friction was recorded in interactions with the densest first layer (03), which had values exceeding 1 .15. The lowest recorded coefficient of static friction was 0.88. This is a preferable range of coefficient of static friction between the two layers suitable to assist in the prevention of down/feather permeation. A high degree of inter-linkage suggests that the staple fibres of the cotton in the first layer can interlock with the filaments of the nonwoven fabric of the second layer, further preventing quills or tendrils from being able to deform the nonwoven second layer around them as would be required in order to project through the second layer.

Table 2

Table 2 shows the cover factor, USTER yarn hairiness index (H) of yarns of the fabric (here given as an average of the hairiness index of 3 warp yarns and 3 weft yarns) and average coefficient of static friction (μ₅) for each of the three types of first layer ("Outers": 01 , 02, 03) construction, the coefficients of friction being averages of two coefficients of static friction each associated with a respective one of the two second layers ("Retainers": R3, R3). Individual coefficients of static friction are shown in Table 3 for each one of six combinations of first and second fabric layer types: 01 with R2; 01 with R3; 02 with R2; 02 with R3; 03 with R2; 03 with R3. Average Ol/ l 01/R2 01/R3 02/ 1 02/R2 02/R3 i 03/R1 03./R2 03/R3 S O.SI 0.S9 0.9! 0.89 1 0.99 0.95

Table 3

When the first layer is of type 01 or 02, the coefficient of static friction with respect to either second layer R2 or R3 is almost identical. The more open first layer of type 01 has a lower cover factor but a higher hairiness as compared to the more tightly woven first layer of the second type 02 - which has a higher cover factor and lower hairiness. Indeed the product of the cover factor and hairiness in these two cases is comparable (01 : 1 133 and, 01 : 1051). This suggests that even when fabric of the first layer is used having a lower cover factor (more open structure), a concurrent proportional increase in yarn hairiness of yarns of the fabric can be useful in maintaining the coefficient of static friction. It is once more suggested that this is evidence of entanglement, friction or otherwise "gripping" between the first and second layers at their interfaces in a synergistic fashion. Example 5

In Example 1 , described above, (no penetrations of down/feather filling), both the first (outer) and second (retainer) layers were not affixed to each other apart from at the seams of the article made from the multilayer fabric and containing the feather/down filling.

Using the same free floating arrangement of first and second layers, within zones between filled compartments of a sample duvet, ultrasonic welding was applied as an alternative to machine-sewn seam construction in a duvet shown in figures 9 to 1 1 . Figure 10 and 1 1 exemplify how ultrasonic seams were only integrated at selected areas ('X'), where baffle walls (33) are required to prevent the migration of filling throughout the duvet. Figure 1 1 demonstrates how the wall of each compartment (the baffle) (33) is welded into place, but can hang freely from the second (SMS) layer (2) and cotton first (outer) layer (1) in order to be bonded to the opposite side. A cross section of the ultrasonic weld (4) is shown in Figure 1 1 , which for this example, was made using an Ardmel Ultrasew H192 unit operating at 35kHz, 1200 watts, 3 mm bonding foot, speed up to 1 1 15 rpm and 12 'stitches' per 3 cm). In these areas, the fibres in the thermoplastic baffle wall tape and the second layer (SMS) were softened and pressured into the cotton outer, creating the bond.

Graph 2 of Figure 21 B shows the measured breaking strengths of the ultrasonic welds, measured according to our adaptation of BS EN IS013935-2:1999; Seam tensile properties of fabrics and made-up articles. Details are provided in Appendix F. A second layer comprising SMS with an area density of 20g/m² was used (retainer layer) in combination with a cotton, woven first (outer) layer having an area density of 92g/m². It was found that seams with little thermoplastic content had the lowest breaking strengths and simply using another additional second layer (retainer - the thermoplastic component) provided a 157% increase in bond strength.

It is possible, using thermoplastic polyurethane adhesives in the assemblies, to achieve breaking strengths up to 100N.

Example 6

Figures 12 and 13 illustrate use of the multi-layer fabric is a pillow (10). The outer seams (1 1) of the pillow are bonded either through traditional machine sewing or ultrasonic welding using a thermoplastic outer decorative piping, leaving the outer cotton (1) first layer and the SMS second layer (2) to remain free-floating, yet retaining feather-filling material (3).

Example 7 Referring to Figure 14, the invention may be used in a filled sleeping bag (15). Figure 15 shows the sleeping bag in cross-section indicated in Figure 14. The inner cavity (16), where the user sleeps, is protected from filling (6) ingress by first and second layers (2 and 3) that are of the same construction outlined above. The outermost layer material (17) may be as specified in embodiments herein, or a may be a weather-proof or laminated fabric.

Example 8

Figures 16 and 17 illustrate views of the use of the multi-layered fabric within down garments, such as a down jacket (30). Where weather-proofing is necessary, the outermost layer (31) may be a commonly used polymeric woven fabric with or without a laminate, or similar material. The first layer (1) and the second (SMS) layer (2) prevent the feather/down filling (3) from penetrating into the user cavity (5). Example 9

The methodology for resistance to permeation testing (BS EN ISO 12131 -1 :1999) was adapted for the evaluation of the ability of embodiments of the invention to contain a popular synthetic alternative filling.

The embodiment comprised of a said first layer constructed from 133 warp yarns per inch and 72 weft yarns per inch, all yarns 40ne English cotton count, for an overall fabric thickness of 377 microns. The cover factor of the fabric was calculated to be 32.41 % with an optical porosity of 12.48%. Air Permeability measurements were taken in accordance with the standard procedure BS EN ISO 9237:1995 for apparel (100Pa pressure drop and a 20cm² test area), However, the testing apparatus used was a Textest Instruments FX3300 Labair 4. The said first layer had an air permeability of 277mm/s. The said second layer in the embodiment comprised of a three layer nonwoven polypropylene SMS structure with a fabric area density of 40gm^"2 and a thickness of 401 microns. Optical porosity was measured at 4.7% and air permeability at 203.1 mm/s.

The filling consisted of 100% polyester hollowfibre ranging between 28.06μηι and 32.13μηι in diameter (mean 30.404μηι, Standard Deviation 1 .044μηι, Coefficient of Variation 3.43). Fibre diameters were ascertained using the procedure outlined in Appendix B.

A quantity of 30g of filling material was used per testing sample. Figure 39 shows an optical image of the hollowfibre filling together with e reference scale bar (250 microns). Following the same methodology as used for down and feather penetration testing, the samples were subjected to 2700 rub cycles over approximately 20 minutes. Of the samples measured none presented any penetration of the filling material, demonstrating 100% barrier efficacy of our materials to this synthetic hollowfibre filling. It is suggested, but not asserted, that because hollowfibres are demonstrably above 2μηι in diameter, the minimal diameter fibrils found attached to down clusters, embodiments of the invention may be successful at preventing this filling and other larger diameter synthetic fills or blend thereof, from migrating through the multi-layer case assembly. Example 10 Figures 26 to 34 illustrate steps in a method for manufacturing a cover for article of bedding or clothing (in this example, a duvet) comprising a fabric described above in any embodiment of the invention. The cover is arranged to be filled with a filling material such as described above (e.g. feathers, down or other fillers). Two opposing pieces/sheets of the fabric are joined to define a container part for containing a filling material and having one or more seams sewn along the fabric pieces which join together the two opposing pieces of the fabric. The seam is isolated from the container part by a substantially continuous ultrasonically-formed weld between the respective second layers (e.g. SMS) of the opposing parts of the pieces of fabric. However, by isolating the sewing from the container part using welds, the article of bedding or clothing may isolate any sewn holes from areas of filling material such as down and feather ultimately placed in the container part.

Multiple adjacent and isolated container parts are formed in the cover in this way. The boundaries/edges of each of the container parts are defined by a plurality of linear welds which define the shape of the container part in question. Sewn seams dividing adjacent container parts of the cover are each contained between two linear such welds extending along substantially the whole length of the sewn seam. The two welds are parallel to each other and parallel to the sewn seam they isolate. Once filled with filling material, each container part may be closed-off by a further such ultrasonic seal. Some of the sewn seams (namely, those that extend between adjacent container parts) are wholly surrounded by a plurality of welds that cross over each other in such a way as to collectively enclose a region of each of the opposing fabric pieces which is isolated from any container part and which contains a sewn seam.

In order to manufacture the exemplary article, first provide two pieces of e.g. SMS nonwoven fabric, and an ultrasonic welder apparatus with ~ 1 cm welding foot. A rotary ultrasonic welding apparatus may be used, or a "stamp" type welder may be used.

1) Position the two equally sized rectangular pieces of SMS nonwoven fabric 28 on top of each other, aligned with edges in register. If desired, one may cut to a desired length and width as shown in Figure 26 (e.g. 205cm length and 1450 width);

2) Cut out a series of spaced rectangular areas (30, Figure 27) of equal depth along one rectangular edge of the opposed fabric pieces, to obtain a crenulated shape 31 as shown in Figure 28. This defines a series (three in this case) of what will be formed into filling tubes 32 in communication with container parts of the article;

3) Using e.g. a 1 cm wide ultrasonic welding foot (e.g. rotary), ultrasonically seal the two opposed pieces of fabric together according to the linear seal lines 33 shown in Figure 29, 3cm away from the edges of the opposed pieces of fabric. Then, ultrasonically seal along the edges of the crenulated parts defining the filling tubes 32 according to the linear seal lines 34 shown in Figure 30. These welds may be as close to the sides of the projecting filling tube parts as possible while still making a good seal i.e. 0.5cm from the edges. The distal edge, end of each filler tube is be left unsealed;

4) Next, ultrasonically seal a plurality (e.g. ten) straight weld lines 35 according to the seal lines shown in Figure 31 . The first line (i.e. from the left hand side) runs the full width 31 .5cm in from the parallel peripheral seal line adjacent the edge of the pieces of fabric (or 34.5cm in from the edge of the pieces). The next weld shall be positioned immediately next to the previous weld, such that two seal lines are placed adjacently in parallel and separated by a 2cm wide zone. The next weld shall be positioned 31 .5cm from the previous weld, and the pattern shall be repeated until all ten lines across the width of the pair of opposed pieces have been welded;

5) The final set of linear ultrasonic welds 36 are formed perpendicular to the last, starting 33.75cm up from the lowest peripheral seal line (or 36.75cm from the edge of the piece) as shown in Figures 32 and 33. These seal lines run each along only a part of the length of the piece, but do not cross over the any of the seal lines 35 that extend into the projecting filling tubes 32. In this way, the filling tubes 32 remain in communication with the whole of the two adjacent container parts they are each associated with via an un-sealed zone indicated by shading 37 in Figure 33 for clarity of identification (in this example, about 7cm in width). Six container parts are formed in this way, with each container part being bounded by ultrasonic weld lines 33 and 35 and each being in communication with a filling tube 32 through which filler material may be injected into the container part. This defines the inner bag part of the article, comprised of the material of the second layer of the fabric of the invention, to which is to be connected an outer (first layer) cover layer thereby, together providing a fabric according to the invention, formed into a cover for a duvet, as follows. First provide a cotton outer fabric, a quantity of piping, and a quantity of filling material. A sewing machine may be used also, as may be a down filling machine if neither sewing nor filling are to be performed manually.

6) Cut two pieces of cotton top cloth 38 to the required dimensions required to accommodate the inner bag, such as shown in Figure 34 for example (i.e. 205cm x

145cm). Place one of these cotton pieces together with the preassembled nonwoven inner bag (Figure 35) and sew along the three rectangular edges 39 that do not possess the projecting tubes 32. The sewing is done outside of the peripheral seal/weld lines 33 of the inner bag 28. The sewing may tack the materials together between projecting tubes 32, again taking care to not puncture inside the peripheral seal/weld lines 33;

7) Next, sew the same two layers (cotton outer 38 and nonwoven inner bag 28) together along the channels 40 that have been formed between parallel adjacent weld lines 35 in the inner bag structure. The sewing line (shown as a dotted vertical lines in Figure 36) must remain in between the weld lines 35 and not perforate either side. Almost the full length of the channels should be sewn, apart from where they run into the projecting tubes 32 - at which point the sewing should stop in line with local edge of the cotton top cloth (indicated by dashed horizontal line 41 in Figure 36);

8) Take the other piece 42 of cotton top cloth and attach piping material 43, closely following all of the peripheral edges of the cloth piece, as shown in Figure 37;

9) Next both component parts (as constructed in steps 7 and 8) are joined. Place the two components back to back so that on one side the piping is visible and on the other the inner bag is visible. Sew along the same line used to fasten the piping in place - again ensuring that no needle passes inside of the peripheral weld line 33 of the inner bag, and fasten the edge containing the projecting tubes in this way at the edge sections/spaces between projecting tubes);

10) Turn the duvet inside out so it becomes the correct way around, with the inner SMS bag 28 inside the outer cotton part (42, 38). Pull the filling tubes 32 out of the assembly so they project, as shown in Figure 38. Next, sew along the previous sewn lines, attaching both the inner and outer pieces together, following the existing sewn lines (dashed lines of Figure 38) should help guarantee that the operator does not sew outside any of the welded channels 40;

1 1) The finished case ready for filling and sealing. Fill the several container parts with desired filling material and, when suitably filled, seal the open ends of the filling tubes, preferably ultrasonically (weld line 44) to enclose the filling material wholly within weld seal lines. The sealed filling tubes may be tucked into the outer bag which maybe sewn closed at its edge there, without penetrating the inner bag.

The embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention which encompass variants, equivalents and other modifications to the embodiments such as would be readily apparent to the skilled person, the scope of the invention encompassing the claims herein. Appendix A

Measurement of Air Permeability All measurements were conducted in accordance with the standard procedure BS EN ISO 9237:1995, using a Shirley Institute Air Permeability tester (5 cm² test area). A pressure of 10 mm H₂0 was obtained for each reading. However if this pressure was unobtainable with a single layer (due to high permeability), more layers were added to increase the resistance. This result was multiplied by the number of layers. Although this ignores non-linear increases in resistance it provides a simple method of quantifying and comparing the air permeability of different materials.

Appendix B Image Analysis Image analysis was conducted on each sample using Image-Pro Plus V.7 software. Prior to analysis, images were either captured by light microscopy (Leica MDG41 with DFC295 Camera) for outer layers, or Scanning Electron Microscopy (Carl Zeiss EVO). Images must be available with a scale (ideally in μηι), and taken at the same magnification (Second Layer (e.g. SMS) materials = 500x, First Layer (Outer Fabric) Materials = 8x). All images should be taken at the highest level of acuity for the magnification, where possible utilizing a Z-stacking feature to improve the clarity of features throughout the specimen. When acquiring images through light microscopy the aperture was kept constant at 50% and no adjustment was made to brightness, contrast or gamma away from their default setting (i.e. 0, 0 and 1 .00 in Image Pro Plus respectively). The Leica DFC295 camera was set at auto exposure, which ranged between 230 and 300ms - outside of these ranges there is a danger of underexposing or overexposing the image. The average sample size for investigation was 1 .55mm by 1 .21 mm, with an image resolution of 1955 pixels by 1532 pixels. The image is taken with the sample flat and the optical axis of the camera substantially perpendicular to the plane of the sample so as to be not oblique thereby avoiding foreshortening in the image.

Image Calibration

For all measurements the image must be calibrated with the image scale. Using Image Pro- Plus, a simple procedure to facilitate these steps is as follows:- - 'Measure'→ 'Calibration'→ 'Spatial Calibration'

- 'Select Units'→ 'Microns'

- Click 'Image'; Drag superimposed scale bar over the image scale bar and adjust to fit. Correct the default measurement to reflect the size of the scale bar. Select OK.

- On Spatial Calibration setting click 'Apply'. The image is now calibrated.

Calculating Optical Pore Size/Optical Porosity

A number of filters may be applied to ensure optical pore size and optical porosity measurements are reliable when determined by image analysis. Based on Image Pro Plus software, the following protocol can be implemented:-

- Ensure the scale bar overlays a fibre and will therefore not affect the results for optical porosity.

- Implement the 'Erode' filter ('Process'→ 'Filters'→ 'Morphological'→'Erode'→ 'Apply') with two passes of 2x2 squares to remove artefacts from the image. Images with obvious distortions, such as large free fibre bundles obscuring the natural pore boundaries should be discarded and replaced with new images representative of the sample fabric.

- If within the image size and resolution parameters provided, image segmentation can be applied to the whole image without an area of interest being selected.

- Run the 'Process'→ 'Segmentation' tool.

- Using the Histogram, set the lower cut off point as 0 and upper cut of point as 75' to only highlight the pores (i.e. dark areas), select a colour and the resolution of the mask as '1 x1 ' then 'Apply Mask' to overlay your image with a two colour (default black and white) image indicating areas obscured by fibres and areas of through pores (see Figure 40). Figure 40 (left) shows 35gsm SMS fabric SEM image taken at 500x magnification, and Figure 40 (right) shows the result of applying a mask to an area of interest (AOI) showing areas occluded by fibres (black) against optical pores (white). The Optical Pore Size may be determined using Image Pro Plus software using the following routine:-

- 'Measure'→ 'Count/Size'→ 'Measure'→ 'Select Measurements'

- Select Area and all three measurements of Pore Diameter (min, max and mean), and adjust thresholds to exclude artefacts (default: white) → 'Measure'. Ensure that all pores are selected then progress to 'View'→ 'Statistics'.

- Copy these statistics to a spreadsheet (Excel) for future reference.

To determine the optical porosity:-

- From 'Select Measurements' only select 'Area' and adjust cut-offs accordingly.

- Calculate the areas of both components (Bright and Dark) representing pores and fibres.

- Measure each and export statistics to a spreadsheet. Add the 'SUM' values for each section.

- For the porosity value divide the 'SUM' occupied by pores by the total 'SUM' and multiply by one hundred to express in percentage term. Determination of Fibre Diameter

If the edges of fibres/yarns are ill defined either take a new, clear image or use a 'Sharpen' or enhance edges through either a 'Sober or 'Roberts' filter. As the image is already calibrated, a cross section of the image was obtained and click 'Measure'→ 'Measurements'. Using the line function draw from one side of the fibre selected to the other (side bars assist this function). The value is automatically recorded. Statistics were based on at least 20 replicates.

Repeat for any other yarns (i.e. both warp and weft yarns) or fibres (i.e. both spunbond and meltblown) to achieve fibre diameters for all aspects of the materials. Appendix C

PMI Porometer (APP-1200AEX) to detect smallest, mean and maximum (bubble point) pore sizes.

The PMI porometer is able to detect fluid flow pathways (i.e. all through pores) which are not identifiable using Image Analysis because they are obscured by other features.

Machine set up

Ensure a steady compressed air supply is available and adjust input to 5 bar pressure. Remove the cap and extract the spacing insert. Using calipers remove the top and bottom metal plates which secure the sample. Remove the small O-ring inside the bottom plate and insert a 12.4mm diameter, circular sample underneath. Replace the O- ring, ensuring the sample is free from wrinkles or creases and return first the bottom plate then the top plate, spacing insert and screw cap.

All porometer testing utilized 'Capwin' software. To work effectively a recent calibration file must be loaded at the start of each batch of tests. After doing this select 'Auto Test'.

Input the characteristics of the material (I.e. thickness and diameter), properties of the wetting fluid (in this case 'Galwick' solution with a surface tension of 15.9 dynes/cm), pressure required (higher for denser samples) and save location. For absorbent/hygroscopic materials such as cotton a dry up/wet up test is recommended. After the dry run is complete the software will pause the test for you to saturate the sample with Galwick (accessing the sample using the process outlined above). Leave the sample for 5 minutes for the Galwick to penetrate all pores. Reassemble the porometer and resume testing. For synthetic materials such as SMS/SES/SM etc. a wet up/dry up test is adequate and will take less time. The machine will not pause, but requires a saturated sample from the beginning.

Following the test the data can be interpreted by 'Caprep' software, which will present the mean, minimum and maximum pore sizes detected along with the corresponding air pressure. A pore distribution bar chart and cumulative flow distribution line graph are automatically generated.

Take the mean, minimum and maximum pore size data and input into a separate spreadsheet to compare with other samples. Appendix D

A method for measuring penetration forces in fabric A strip of sample material/s (500mm x 80mm) was clamped in the sample clamping plate. The plate used comprised two annular discs each with a 20cm outside diameter and a 5cm² internal cavity surrounded by a rubber sealing ring to more securely fasten the specimen between them (sandwiched) and held firm across the inner annular cavity. When testing a multilayered fabric, the second (retainer) layer was placed facing upwardly in first contact with the needle, to simulate penetration from the inside of a garment or the like. The clamping plate was mounted to an Instron 4301 tensile testing apparatus, similarly to BS EN ISO 9073-5:2008; Determination of resistance to mechanical penetration (ball burst procedure).

A 1 .5mm diameter darning needle with conical tip was used to undertake mechanical penetration of the samples. The minimum shaft length gripped by the testing apparatus was 20mm. A 100N load cell was used for measurements. This was connected to a computer running Picoscope software.

After mounting the sample (within the claming plate) to the testing apparatus, the needle was lowered until the point of the needle only just makes contact with the specimen. This prevents lateral movement of the needle during its descent. For single samples the needle protruded 35mm from the bottom edge of the upper jaw clamp, for double layers this was 45mm (due to larger elongations). The darning needle was perpendicular to the test specimen during each test. The speed of descent of the needle was controlled to 100mm/min, and the Instron's load balance was set to zero. Data recording software was commenced and the Instron activated to commence the test. The test was stopped manually after penetration of the layer(s) occurred.

Needle Dimensions: Tip angle = 85 degrees, thickness at end of tip = 0.2mm, thickness at end of point taper 1 .2mm, thickness 2mm down from tip point = 1 .38mm. Peak penetration force (N) and elongation (%) for single nonwoven and woven materials

ICON Load Ceil - 3.5cm project! ng darning needle ICON toad Ceil - 3.5crn projecting darning needh

Test No. Materia! Peak Force Elongation Test No. IViaterial Peak Force Elongation

1 Ol 8.867 6.33 31 20gxm S 1.769 6.51

2 Ol 6.287 5.15 32 R2 3.592 7.53

3 Ol 6.969 5.42 33 R2 2.583 6.87

4 Ol 7.79 - 34 R2 2.612 6.67

5 Ol 7.192 5.12 35 R2 2.883 7.94

6! 01 6.526 5.79 36 R2 2.191 6.81

7 Ol 8,005 5,32 37 R2 2.91 7.03

S Ol 8.056 .5.54 38 R2 1,71 6.57

9 Ol 8.539 5.25 39 R2 2.591 7.51

10 Ol 6.958 5.24 40 R2 3.101 7.72

.11 Ol &862 5.12 Average 2.59 7,12

Average 7,64 5.43 St. Oev 0.58 0.52

St. Dev 0.91 0.38 CV 22,48 7.25

CV 11.94 7.01

12 02 17.39 - 4.1 R3 3.162 7. S

13 02 16.19 - 42 R3 4.714 6.21

14 02 15.37 S 43 R3 4.142 6.11

15 02 16.61 6.8 44 R3 5.702 7.09

.16 02 17.35 6.87 45 R3 3,778 6.05

17 02 15.25 6.52 46 R3 3,412 6.1

18 02 17.11 6.42 47 R3 3.93 6.79

19 02 17 7.19 48 R3 4, 749 7.1

20 02 16.86 6.92 49 R3 859 7.86

21 02 15.96 7.5 50 R3 5.493 6.99

Average 16.5.1 7.03 Average 4.39 6.75

St Dev 0.78 0.52 St. Dev 0.35 0.61

CV 4.74 7.43 CV 19.35 9.01

The left hand tables relate to woven fabrics comprising different woven fabric constructions. The right hand tables relate to nonwoven fabrics comprising SMS having either 20g/m² or 35g/m² area density. Peak penetration force (N) and elongation (%) for two layer assemblies

100N Load Cell - 4.5cm projecting darning needle 100N Load Cell - 4.5cm projecting darning needi<

Test No. Material Peak Force Elongation Test No. Material Peak Force Elongation

5l! Ol & R2 \ 16.17 ! 7.01 61 01&R3 15,23 \ 6.25

52S 01&R2 i 14.92 i 6.72 62 01&R3 16.3 i 6.84

53! 01 & R2 j 15.33 j 6.4 63! 01 & R3 19.81 ; 7.12

54S 01&R2 ; 16.04 i 6.42 64101 & R3 17.18 \ 5.53

S5S 01&R2 i 17.56 i 7.41 65 01&R3 16.14

56! 01 & R2 i 15.84 i 6.2 66 01 & R3 11.9 i 5.76 i 5⁷L!?i-*H- \ 16.04 j 6.42 i 67 01&R3 17.16 ] 6 I

5S!oi&R2 Ϊ 16.16 1 5.52 68 01&R3 16.14 \ 5,79

59s Ol & R2 j 16.38 j 5.35 69 01&R3 16.57 I 6.39

60! Ol&R2 i 16.91 i 6.71 70 01&R3 17.04 i 7.17

! Ave rage I 16.135 j 6.416 i \ Average 16.35 i 6,32 \

1st. Dev \ 0.74 \ 0.62 ist. Dev 1.97 \ 0.61

!cv i 4.58 i 9.73 icv 12.06 i 9.64 j

I 7¾ 02&S¾ \ i.;i;.i«g¾id i 82 02&R3 20.38 j 9

72S 02&R2 18.38 ! 9.81 83 02&R3 18.1 i 9,15 j i ?s! ?<%¾ i i 84I 02&R3 20.81 ; 9.82

74! 02&R2 20.46 1 10.72 85 02&R3 22.31 j 9.35

75S 02&R2 22.64 i 9.81 86102 & R3 23.21 : 10.39

76! 02&R2 21.78 i 9.14 87 02&R3 18.24 j 9.14

77! 02&R2 23.07 ; 9.16 88102 & R3 22.74 \ 13.04

78S 02&R2 22.56 i 9.36 i S9 02 & R3 21.95 i 9.5

79! 02&R2 22.79 i 9.47 90 02 & R3 22,55 j 9.13

80! 02&R2 21.52 ! 8.91 9.1 02 & R3 27.01 \ 9.38

8l! 02&R2 23.81 i 10.03 \ Average 21.73 i 979 ;

! Ave rage \ 21.89 i 9.60 i ISt. Dev 2.59 j 1.21

SSt. Dev 1.64 i 0.56 icv 11.90 j 12.40

!cv \ 7.474121822! 5.802927351 i These tables relate to the multi-layered fabric comprising the first and second layers having 80g/m² area density (Ol) in the woven fabric layer (upper tables) or 92g/m² area density (02) in the woven layer (lower tables). Left hand tables relate to nonwoven fabrics comprising SMS having an area density of 20g/m² and right hand tables relate to nonwoven fabrics comprising SMS having 35g/m² area density.

Test sample 3 is highlighted, and excluded from statistical analysis due to metal on metal contact between the upper jaw and clamping plate on the Instron testing equipment. These initial experiments informed to decision to increase needle projection to 45mm for testing two layer assemblies. Appendix E

Measuring the Static Coefficient of Friction between nonwoven and woven fabrics Sled Test method based on INDA standard 1ST 140.1 (95)

Figure 41 shows a diagram of an apparatus or assembly for determining Coefficients of Friction. Where a = sled, b = plane, c = supporting base, d = lower clamp, e = low friction pulley and f = constant speed tensile head. A length of non-elastic string connects the pulley to the tensile head via the pulley.

Following the procedure outlined in INDA 140.1 (95), the following alterations were made to the procedure:

1) Sled - The sled dimensions were 42mm width x 50mm length x 15mm depth. The sled was made from aluminium and weighed 70g;

2) Samples - As the interest lies in the friction coefficient between two different materials, the block was always covered by a nonwoven fabric of layer 2 while the outer cotton fabric of layer 1 was affixed to the plane (one sample tested in the warp direction and the second in the weft direction). The bottom samples are 150 x 150mm squares;

3) Tensile Head Speed - 100mm/min rather than 150mm/min;

4) Travel - The test was concluded when the rear of the sled crossed where the front of the sled started (as indicated by a drawn line).

Calculations of static coefficient of friction (μ₅) were determined according to: μ₅ = A B

where :

A_s = initial motion scale reading (g)

B = Sled Weight (g)

Appendix F

Configuring Zwick Z010TN and textXpert software for testing standard seam strength according to BS EN ISO 13935-2:1999; Seam tensile properties of fabrics and made-up articles.

Method for testing baffle wall and piping strength

The strength of ultrasonically welded seams has been shown to depend upon construction methods (i.e. what materials are being bonded and how). Experiments were conducted using the Ardmel Ultrasew H192 to weld the seam (specific power settings provided where appropriate). All tensile tests are conducted and recorded using a Zwick Z010TN and textXpert software. The mechanical set up used 30mm jaws and 200N load cell at a gauge length specified for each experiment. Peak force in N was recorded along with the corresponding strain as a percentage.

Experiment 1 - Standard seam.

Samples were prepared in accordance with BS EN ISO 13935-2:1999. The second (SMS) layer was layered on the inside of the cotton sample before ultrasonic welding and as such (from the under-side upwards) the layering was as follows: First layer - Second layer - Second layer - First layer (e.g. Cotton - SMS - SMS - Cotton) and this constituted the area of the weld. The Ardmel Ultrasew H192 was set to a power output of 60%, a speed of speed set at '9' and 20mm of pressure. With the gauge length set at 200mm the sample was placed with a second layer (e.g. of SMS) and first layer (e.g. cotton) in both top and bottom jaws, loading the sample according to the standard. An extension of 50mm/min was implemented until a preload of 0.2N was reached. Then, an expansion of 100mm/min continued until the second (e.g. SMS)layer separated from the first (e.g. cotton) layer completely, or one part of the assembly ruptures. Experiment 2 - Baffle Walls

Samples were constructed according to Figure 22 where item 100 is the baffle wall tape, item 2 is the retainer layer, item 3 is the cotton first (outer) layer and the weld-line is shown as a dashed line. Experiment 2 used the same procedures and equipment as Experiment 1 apart from not cutting samples down to standard size. Instead they were left at 100cm wide to be clamped, with the baffle wall gauze in the upper jaw with the rest of the assembly clamped into the lower jaws. This is shown in Figure 22 where; item 1 10 is the upper and lower jaws respectively, item 100 is the baffle wall tape, item 4 is the weld zone, item 2 is the retainer layer and item 1 is the first layer (e.g. cotton outer layer). The gauge length was set to 100mm to accommodate their shorter construction. Experiment 3 - Piping

Samples were constructed in a similar way to Experiment 1 - however a section of piping, a synthetic decorative trim for the edges of duvets and pillows, was incorporated into the weld zone. This is shown in Figure 23, where; item 2 is the second (retainer) layer, item 1 is the first (e.g. cotton outer) layer, item 300 is the piping tape (shown as a cross section) and item 4 is the weld zone. The bonding of the bottom two fabric layers to the piping takes place before the top two fabric layers are bonded to the assembly. Figure 24 shows the assembly before the top two layers are bonded, where; item 1 is the cotton fabric, item 300 is the piping tape and item 2 is the retainer layer.

Claims

CLAIMS:

1 . A multi-layered fabric including: a first layer comprising a woven or knitted fabric having an optical porosity of between 0.06% and 35%, or a porosity of between 50% and 95%; and, a second layer comprising a nonwoven fabric or web having an optical porosity of between 0.1 % and 15%, or a porosity of between 75% and 98%.

2. A multi-layered fabric according to any preceding claim in which the second layer includes fibres of plastics and/or polymer material which comprise one or more of: spunbond, meltblown, electrospun or forcespun fibres.

3. A multi-layered fabric according to any preceding claim in which the second layer includes a layer comprising spunbond fibres and a layer comprising one of: meltblown fibres, electrospun or forcespun fibres.

4. A multi-layered fabric according to any preceding claim in which the second layer includes a layer comprising meltblown fibres or electrospun fibres or forcespun fibres between two layers which each comprise spunbond fibres.

5. A multi-layered fabric according to any preceding claim in which the second layer includes meltblown fibres or electrospun fibres or forcespun fibres which comprise between 10% and 50% of the second layer by weight.

6. A multi-layered fabric according to any preceding claim in which the second layer has an air permeability of between 25cm³/cm²/s and 120cm³/cm²/s.

7. A multi-layered fabric according to any preceding claim in which fibres of the second layer have an average fibre diameter which is less than 9 μηι.

8. A multi-layer fabric according to any preceding claim in which the average inter-fibre pore diameter of the second layer is between 9μηι and 12μηι.

9. A multi-layer fabric according to any preceding claim in which the second layer has a fabric area density of between 10gm^"2 and 10Ogm^"2.

10. A multi-layered fabric according to any preceding claim in which the first layer comprises staple fibre yarns that are woven or knitted together.

1 1 . A multi-layered fabric according to any preceding claim in which the hairiness of yarns of the fabric of the first layer is between 2 and 20 according to the USTER Hairiness Index (H).

12. A multi-layer fabric according to any preceding claim in which the cover factor of the first layer is less than 40.

13. A multi-layer fabric according to any preceding claim in which the average inter-yarn pore diameter of the first layer is between 5μηι and δθθμηι.

14. A multi-layer fabric according to any preceding claim in which the first layer has a fabric area density of between 20gm^"2 and 120gm^"2.

15. A multi-layer fabric according to any preceding claim in which the first layer has an air permeability of between 3cm³/cm²/s and 250cm³/cm²/s.

16. An article comprising down and/or feathers contained within a container formed from a multi-layered fabric according to any preceding claim.

17. An article of clothing or bedding comprising the article of claim 15.

18. An article comprising multi-layered fabric according to any of claims 1 to 15 and including a first portion of a said fabric ultrasonically welded to a second portion of a said fabric wherein the second layer of the first portion is in direct contact with the second layer of the second portion where welded.

19. An article according to claim 20 and any one or more of claims 16 or 17.

20. A method of manufacturing a multi-layered fabric comprising: providing a first layer comprising a woven or knitted fabric having an optical porosity of between 0.06% and 35%, or a porosity of between 50% and 95%; and providing a second layer comprising a nonwoven fabric or web having an optical porosity of between 0.1 % and 15%, or a porosity of between 75% and 98%; arranging the second layer and the first layer together to provide a multi-layer fabric.

21 . A method according to claim 20 in which the second layer includes fibres, which comprise one or more of: spunbond, meltblown, electrospun or forcespun fibres.

22. A method according to any of claims 20 and 21 including attaching the second layer to the first layer.

23. A method according to any of claims 20 to 22 including forming the second layer to include a layer comprising spunbond fibres and a layer comprising one of: meltblown fibres, electrospun or forcespun fibres.

24. A method according to any of claims 20 to 23 including forming the second layer to include a layer comprising meltblown fibres or electrospun fibres or forcespun fibres arranged between two further layers which each comprise spunbond fibres.

25. A method of manufacturing an article comprising providing multi-layered fabric according to any of claims 1 to 15 and ultrasonically welding a first portion of a said fabric to a second portion of a said fabric wherein the second layer of the first portion is in direct contact with the second layer of the second portion where welded.