WO2006010482A1

WO2006010482A1 - A particulate detergent composition, and packaging therefore

Info

Publication number: WO2006010482A1
Application number: PCT/EP2005/007622
Authority: WO
Inventors: Jane Elizabeth Ormond
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 2004-07-27
Filing date: 2005-07-12
Publication date: 2006-02-02
Also published as: AR049741A1; GB0416711D0; CN101027384A; BRPI0513874A; EP1781769A1

Abstract

A particulate fabric treatment composition having a dynamic flow rate of a least 90ml/s, characterised in that the particulate detergent composition is contained in a water insoluble elongate tubular sachet, having one or more longitudinal seals and one or more end seals.

Description

A particulate detergent composition, and packaging therefore.

The present invention relates to a particulate fabric treatment composition having a dynamic flow rate of at least 90 ml/s.

In recent times, fabric treatment compositions in powder form have been increasingly superseded in the market by ^λunit dose' products in the form of compacted tablets and more recently water soluble capsules containing liquid. Normally, one or two unit dose products are simply placed in the washing machine with the fabrics.

The present invention provides a particulate fabric treatment composition having a dynamic flow rate of at least 90 ml/s, characterised in that the particulate detergent composition is contained in a water insoluble elongate tubular sachet.

The provision of a unit dose of a fabric treatment composition in particulate form is advantageous because it offers high washing efficiency as compared with, for example, other unit dose formats such as compacted tablets.

The term "particulate" as used herein is intended to include powder, agglomerated or descrete particles, granules, or any other solid particles.

The use of an elongate tubular body containing a particulate fabric treatment composition having a dynamic flow rate of at least 90 ml/s is advantageous in that it reduces the likelihood that the flow of the particulate composition from tubular container becomes blocked.

The longer the length in comparison with the width, i.e. the more narrow the tube, the greater the likelihood of an interruption in flow from the tube during dispensing. Therefore, the dynamic flow rate should be at least 90 ml/s and the may be at least 100 ml/s. More preferably the dynamic flow rate is at least 110 ml/s.

Preferably the particulate fabric treatment composition has a compressibility of less than 25%; further preferably less than 20% and even further preferably less than 17%.

In a particularly preferred embodiment the particulate composition has a compressibility of less than 15%. Reducing the compressibility of the composition is advantageous as this further improves flow properties of the composition within the tubular sachet during dispensing thereby reducing the likelihood of blockages.

Compressibility as used herein, is measured by compressing a known volume of particulate composition by the application of a standard weight, at defined conditions of temperature and humidity after which the volume reduction is noted. The method used is described below.

The length of the sachet should be greater than the width to provide the elongate tubular shape. Such a shape is advantageous in terms of e.g. ease of handling. The ratio of the (longitudinal) length of the sachet (before filling with the particulate composition) to the width of the sachet (again, before filling) is preferably from 3:1 to 6:1. Most preferably, the ratio is 4:1 to 5.1.

The length of the sachet (measured before filling and along the longitudinal axis) may be 100mm -300mm, preferably 150 -

250mm and further preferably 170 -200mm.

The width of the sachet (measured before filling and perpendicular to the longitudinal axis) may be 20mm - 50mm, preferably 30-45mm.

In one example, the length is 185mm and the width is 45mm, so that the ratio is approximately 4:1 and the dynamic flow ratio of the composition is at least 100 ml/s.

The sachet is preferably a three-seemed sachet with a lengthwise seam (5) formed as a sealed flat seam. The sachet is preferably closed at each end by sealed transverse seam and may have a lateral incision (4) for opening.

Alternatively, or additionally the ends may have incisions e.g. by means of ^λzig-zagged' edges to allow opening.

The lengthwise seam may be a fin or ^λlap' seal. A lap seam is formed where two layers of film overlap, with the outermost face of the inner layer in contact with the innermost face of the outer layer. The two layers are then bonded together either by use of an adhesive or by the formation of a weld. A weld requires the surface layers of the film to be made of a thermoplastic material (i.e. one which will melt when a high temperature is applied) . A welded bond is formed by melting the surface layers, allowing the molten layers to merge together, then allowing resolidification to take place.

The fin seam is formed by contacting the inner faces of two layers of film together and then bonding the two layers together. For a fin seam, a weld is frequently used to bond the inner faces of the film together. This requires the inner layers of the film to be made from a thermoplastic material.

Compared to the lap seal, the fin seal requires a greater area of flexible film for the same volume of package.

However, the topological constrains on the formation of a lap seal mean that it can only be conveniently formed at an early stage in the manufacture of a package, before product is in the partially formed package, as it requires the application of a sealing bar to the inner and outer surfaces of the package. By contrast, the fin seal can be used when there is product in the package, and to form the final seam closing the package, as sealing bars have only to be applied to the outer surfaces of the package.

Alternatively, it may be formed by sealing a lengthwise seam sealing strip onto the reciprocally abutting lengthwise edges (taping seam) .

' The sachet is preferably formed of a water-insoluble thermoformable plastics material such as polystyrene, high or low-density polyethylene, polypropylene. An insoluble sachet is advantageous if the user has wet hands (eg.which may happen as a result of pre-treatment or in the case of hand washing) . Water soluble sachets and tablets may, in such circumstances begin to prematurely dissolve whereas a non-soluble sachet would not.

However, in principle, other materials such as paper, metal (e.g. aluminium) foil could be used to create the container.

All of the above polymers include the aforementioned polymer classes whether as single polymers or as copolymers formed of monomer units or as copolymers formed of monomer units derived from the specified class or as copolymers wherein those monomer units are copolymerised with one or more comonomer units.

Blends (i.e. not copolymers) of two or more polymers recited herein, may also be used.

A plurality of sachets according to the present invention may be formed together end to end, e.g. on a vertical form fill and seal machine. Batches of sachets may be provided held together in ^strings' a line of weakness in the material separating each sachet from an adjacent sachet. Then, in use, the consumer may tear-off an individual container leaving the remainder in the ^string' .

Fill volumes of contents of the sachet are from 3Og to 10Og, for example 4Og to 7Og. In one example the fill volume is 5Og. Exemplary powder formulations are below. Parts and percentages are by weight unless otherwise stated.

EXAMPLES 1 and 2 are particularly suitable for handwashing formulations.

Example 1

The following formulation was prepared by drum drying alpha- olefin sulphonate paste (70 wt%), alkyl ether sulphate paste (70 wt%) and sodium alkaline silicate solution to form granules. Sodium carboxymethyl cellulose, fluorescer and enzymes were subseguently admixed.

EXAMPLE 2

Alpha-olefin sulphonate (38 wt% solution), alkyl ether sulphate (28.5 wt% solution), fluorescer and sodium alkaline silicate (42 wt% solution) were mixed to form a slurry which was drum-dried. The resulting product was granulated in a Lδdige Ploughshare mixer with additional AOS (38 wt% active) , silica, sodium carboxymethyl cellulose, enzymes (Enzyme Ace protease/lipase granules and cellulase) and perfume. Raw materials and their suppliers were as in Example 1. The resulting formulation and some physical properties are shown below.

Physical properties

Bulk density 530 g/litre Dynamic flow rate 100 ml/sec Compressibility 19.3% v/v Dissolution (t9o) 30 sec

The tgo dissolution time is the time required for 90 wt^! dissolution (as measured by a conductivity method) .

EXAMPLES 3-6 Medium-Low bulk density particulate for formulations.

Preparation of granular components

The following powder components were prepared by spray- drying. F1-F4. were typical detergent base powders containing substantial levels of builder, anionic surfactant and nonionic surfactant. B1-B3 were builder granules.

Sodium linear alkyl benzene sulphonate produced by neutralisation of Dobanic Acid 103 ex Shell.

² Nonionic surfactants ex ICI.

Granular components Al, A2 and A3 containing high levels of anionic surfactant were prepared by non-spray-drying processes as follows.

For component A2, sodium primary alcohol sulphate particles (NaPAS) were manufactured from a paste containing 70% neutralised cocoPAS and 30% water, dried in a dryer/granulator supplied by VRV SpA, Italy.

The temperature of the material entering the drying zone was set at 60⁰C and a small negative pressure was applied to the drying zone. A throughput in the flash drier of 120 kg/hr of paste was used. The temperature of the wall of the drying zone was initially 14O⁰C. The heat transfer area of the drying and cooling zones was 10 m² and 5m² respectively. The temperature of the wall of the drying zone was raised in steps to 170⁰C. Correspondingly, the throughput was increased in steps to 430 kg/hr at 170°C. At each step, the process conditions were stabilised for 15 minutes. The particles then passed to a cooling zone operated at a temperature of 3O⁰C.

For component Al, sodium linear alkyl benzene sulphonate particles (NaLAS) were produced by neutralising LAS acid with sodium carbonate. Furthermore, zeolite MAP was dosed as a layering agent and optionally sodium sulphate was dosed as well. A 1.2 m² VRV flash-drier machine was used having three equal jacket sections. Dosing ports for liquids and powders were situated just prior to the first hot section, with mid-jacket_ dosing ports available in the final two sections. Zeolite was added via this port in the final section. An electrically-powered oil heater provided the heating to the first two jacket sections. Ambient process water at 15⁰C was used for cooling the jacket in the final section. Make-up air flow through the reactor was controlled between 10 and 50 mVkg hr by opening a bypass on the exhaust vapour extraction fan. All experiments were carried out with the motor at full-speed giving a tip speed of about 30 m/s. Screw-feeders were calibrated to dose sodium carbonate and zeolite MAP for layering. The sodium carbonate and liquids were added just prior to the first hot section and zeolite layering was added into the third section which was cold. The minimum level of zeolite was added to give free-flowing granules leaving the drier. A jacket temperature of 145⁰C was used in the first two sections, with an estimated throughput of components 60 to 100 kg/hr. A degree of neutralisation of alkyl benzene sulphonate of greater than 95 was achieved. The bulk density, surfactant level and compressibility of the particles was then measured.

Alpha-olefin sulphonate (AOS) granules A3 were produced in a similar manner by drying an AOS paste containing 70% neutralised AOS and 30% water in a dryer/granulator supplied by VRV SpA, Italy. The temperature of the material fed into the drying zone was set at 60⁰C and a small negative pressure was applied to the drying zone. The temperature of the wall of the drying zone was initially 140⁰C. The heat transfer areas of the drying and cooling zones were 0.8 m² and 0.4 m² respectively. The temperature of the wall of the drying zone was raised in steps to 155°C. The particles then passed to a cooling zone operated at a temperature of 3O⁰C and were collected as free flowing granules.

The anionic surfactant granules had the following compositions:

A granular component Nl containing nonionic surfactant was manufactured by the following process.

A mixture of sodium sulphate, sodium carbonate and Sokalan (Trade Mark) CP5 (acrylic/maleic copolymer ex BASF, Na salt) was spray-dried to form a porous carrier powder of the formulation given below. The slurry was made by successively dosing Sokalan CP5, sodium sulphate and sodium carbonate in water. The moisture content of the slurry was 55% at a temperature 9O⁰C. The slurry was sprayed in a counter-current spray-drying tower using an inlet temperature of 350-400°C.

Nonionic surfactant was sprayed into this spray-dried carrier in a rotating pan-granulator, resulting in the following final composition Nl.

A second nonionic surfactant granule N2 was manufactured by the following procedure.

Silica (Sorbosil TC15 ex Crosfield) was dosed into a Fukae FS30 granulator and a mixture of nonionic surfactant (Synperonic 7 supplied by ICI) and Pristerene 4916 (fatty acid supplied by Unichema) at a temperature of approximately 60⁰C was added on top of the solid. Thereafter, 50% sodium hydroxide solution was sprinkled on top. Directly after addition of the sodium hydroxide, the mixture was granulated using an agitator speed of 200 rpm and a chopper speed of 3000 rpm. Granulation time was in the region 30-60 seconds. The resulting powder was layered with silica and removed from the granulator. The composition was as follows:

The properties of the various granules are as shown in the following Table.

With a selection of the above components, detergent base powders having the following compositions were prepared in a Vblender by addition of the various powders followed by 5 minutes mixing. The powder properties are shown in the following Tables.

Examples 3-5

Sodium tripolyphosphate built compositions having a medium surfactant level were manufactured by blending the following components. All three compositions had the same final composition (ie that of base powder F2) .

Example 6

A Zeolite-built composition as shown in the following table, having a medium surfactant level, was manufactured by dry- mixing the components.

The antifoam granule contained 70 wt% sodium carbonate, 18 wt% silicone oil and 12 wt% filler materials.

The base powder has been reformulated to include components of compressibility less than 17%, provides a low compressibility and high DFR.

Dynamic flow rate is measured by the following method.

The apparatus used consists of a cylindrical glass tube having an internal diameter of 35 mm and a length, of 600 mm. The tube is securely clamped in a position such that its longitudinal axis is vertical. Its lower end is terminated by means of a smooth cone of polyvinyl chloride having an internal angle of 15° and a lower outlet orifice of diameter 22.5 mm. A first beam sensor is positioned 150 mm above the outlet, and a second beam sensor is positioned 250 mm above the first sensor.

To determine the dynamic flow rate of a powder sample, the outlet orifice is temporarily closed, for example, by covering with a piece of card, and powder is poured through a funnel into the top of the cylinder until the powder level is about 10 cm higher than the upper sensor; a spacer between the funnel and the tube ensures that filling is uniform. The outlet is then opened and the time t; (seconds) taken for the powder level to fall from the upper sensor to the lower sensor is measured electronically. The measurement is normally repeated two or three times and an average value taken. If V is the volume (ml) of the tube between the upper and lower sensors, the dynamic flow rate DFR (ml/s) is given by the following equation:

DFR = V ml/s t

The averaging and calculation are carried out electronically and a direct read-out of the DFR value obtained. Compressibility

The method of measuring compressibility used in the present invention is as follows.

The experiment is carried out at 20-25⁰C and a relative humidity of about 40%. These values represent typical ambient conditions in a northern European indoor laboratory environment. The exact relative humidity at which the measurement is carried out is not critical, provided that it is not so high that the samples take up moisture.

The apparatus comprises a perspex cylinder with an internal diameter of 54 mm and a height of 170 mm. The side of the cylinder is graduated in millimetres. A piston is provided which fits the internal diameter of the perspex cylinder.

The top of the piston has means to support a weight, whereby pressure can be applied to detergent powder contained in the perspex cylinder. The combined mass of the piston and the weight is 25 kg.

To measure the compressibility of a sample, the perspex cylinder is filled with particulate detergent composition

(herein after "powder") . The top of the layer of powder is levelled by removing superfluous powder with a straight¬ edge. Thus, a standard volume of powder is tested. The initial volume is measured by means of the scale on the side of the cylinder. The piston and weight are then lowered onto the surface of the powder and are allowed to rest freely on the powder for 60 seconds. The volume of the powder after 60 seconds is measured by means of the scale on the side of the cylinder.

The volume reduction is used to calculate the compressibility using the following equation:

Compressibility = (initial volume - final volume) x 100

(in %) initial volume

The present invention will now be explained in more detail by reference to the following description of various non- limiting embodiments and with reference to the accompanying drawings in which:- Figure 1 shows a sachet according to one embodiment of the invention.

Referring to the drawing, a elongate tubular sachet 1 containing a particulate detergent composition.

The sachet 1 comprises a longitudinally folded packaging wrapper having a longitudinal seal 3 and transverse end seals 5,7 at respective ends 9,11 of the wrapper (ie. a "three-seamed" sachet) .

In the embodiment shown, the longitudinal seal is a fin seal, formed by contracting the inner faces of the fin together and then bonding, eg. welding the two layers together. If welding is used to bond the surfaces, the bonding inner faces need to be made of thermoplastic material.

The end seals 5 and 7 may be heat sealed. The edges have a zig-zag configuration to allow for easy opening of the pack at either end.

The sachet measured before filling is 45 mm wide and 185 mm long halved length to width ratio of about 4:1.

The sachets are made using vertical form fill and seal

(VFFS) machinery so that a long tube is first formed from a sheet of material and creating a longitudinal lap seal as described above. The tube is then moved to a filling station where a section is flattened at a sealing device positioned below the filling station and sealed transversely using an ^λimpulse' sealer. The tube is then moved downward through a predetermined distance and filled with a dose of the particulate detergent composition. A second seal is then formed across the tube, above the fill level.

The filled sachet cut away as in this example or a line of weakness introduced before a second transverse seal is formed (forming the bottom seal of the next sachet) so that the sachets can be separated later (eg. by the user) .

A sachet 185mm long and 45mm wide with end seals 5-7mm in length, can accommodate approximately 45-5Og, and preferably 47g detergent powder.

A dynamic flow rate of at least 100 ml/s is advantageous for such dimensions.

In the light of the described embodiment, modifications of those embodiments, as well as other embodiments, or within the scope of the present invention as defined by the appended claims, will now become apparent to persons skilled in this art.

Claims

1. A particulate fabric treatment composition having a dynamic flow rate of a least 90ml/s, characterised in that the particulate detergent composition is contained in a water insoluble elongate tubular sachet, having one or more longitudinal seals and one or more end seals.

2. A particulate fabric composition according to claim 1 wherein the ratio of the length (before filling) to the width (before filling) of the sachet is from 3:1 to 6:1.

3. A particulate fabric composition according to claim 2 wherein the ratio is 4:1 to 5:1.

4. A particulate fabric composition according to any preceding claim wherein the length of the sachet is 100- 300mm.

5. A particulate fabric composition according to any preceding claim wherein the width of the sachet is 20- 50mm.

6. A particulate fabric composition according to any preceding claim wherein the compressibility of the particulate composition is less than 25%.

7. A particulate fabric composition according to claim 7 wherein the compressibility is less than 15%.