WO2008148702A1

WO2008148702A1 - Disposable humidifier for use with tobacco products

Info

Publication number: WO2008148702A1
Application number: PCT/EP2008/056638
Authority: WO
Inventors: Darryl Stephenson; Joseph Peter Sutton
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2007-06-05
Filing date: 2008-05-29
Publication date: 2008-12-11
Also published as: BRPI0812331A2; CA2687053A1; AU2008258678A1; EP2155008A1; AU2008258678B2; GB0710778D0; NZ582052A

Abstract

A disposable humidifier for use with tobacco products comprises a moisture-releasing element that emits water vapour and a semi-permeable one-way membrane that encloses the moisture-releasing element and transmits water vapour from the moisture-releasing element and substantially blocks the passage of water vapour and liquid water to the moisture-releasing element. The humidifier may also have an outer layer that is impermeable to water vapour and which is removed or breached before use of the humidifier in a package or container of tobacco product. The humidifier may be incorporated into the package.

Description

DISPOSABLE HUMIDIFIER FOR USE WITH TOBACCO PRODUCTS

BACKGROUND OF THE INVENTION

The present invention relates to a disposable humidifier for use with tobacco products.

The tobacco in products such as cigarettes, cigars and loose tobacco for pipe smoking or roll-your-own cigarettes is prone to drying out both during the pre-use storage period and particularly after the product packaging has been opened. This is undesirable, since tobacco becomes less palatable as it dries.

Expensive cigars are generally stored in specially designed humidors specifically to address this problem by keeping the cigars at a desired level of humidity to prevent drying. A more rudimentary approach is often used by consumers of loose tobacco; a piece of apple or potato peel placed in the tobacco pouch or tin can help to keep the tobacco moist or can re-moisten tobacco that has become too dry. However, this method may not be considered hygienic, and may taint the tobacco with unwanted scents or flavours.

Various humidification devices and moisture dispensers have therefore been proposed for use with tobacco products, in particular for use in tobacco pouches and tins and cigarette packs. Typically, the devices comprise a source of moisture that can emit water vapour which is surrounded by a permeable enclosure such as a housing, casing, layer or pouch which keeps the moisture source separate from the tobacco but allows the water vapour to be transmitted to the tobacco. The moisture source is often some form of water- absorbent medium such as cotton wool, blotting paper, sponge, florists' foam, or polyacrylamide gel or crystals, which is soaked with water or salt solution. The permeable enclosure may be rigid or flexible, and may be made permeable by the provision of perforations or apertures therein, or may be an inherently permeable membrane material. Some devices are incorporated into tobacco packages, while others are independent devices that can be inserted into a tobacco product container. Examples of such devices can be found in GB 2,345,431, GB 2,265,295, GB 1,369,992, GB 741,475, GB 567,141, GB 308,127, GB

119,489, EP 531,075, EP 363,194, EP 348,840, US 5,957,380, US 5,957,277, US 5,829,452, US 3,801,011, US 1,874,989, US 1,871,419, WO 02/12089, DE 4000143, DE 20 2005 008 520, DE 20 2005 010 286 and FR 2,619,289. Some devices include an outer non-permeable enclosure to prevent moisture loss before the device is used. For example, US 5,957,380 describes a plastic tube containing a porous material holding a humidification solution of glycol, water and saturated salt, the tube having end caps which are removed to let water vapour out when the device is placed in a cigar container. US 3,801,011 describes a humidity control device comprising a sheet-like carrier such as an adhesive tape which carries a layer of water-containing capsules having vapour-transmissive walls, and which is supplied in a sealed plastic bag. In all of these examples, the permeable enclosure allows water and/or water vapour to pass through in both directions. In some cases, this is to allow the user to hydrate the water- absorbent medium before use, which generally means that the device can be used many times. In other cases, two-way water vapour transmission allows the water- absorbent medium to both give out and take up water vapour, providing full humidity control rather than humidification only.

SUMMARY OF THE INVENTION A first aspect of the present invention is directed to a disposable humidifier for use with tobacco products comprising: a moisture-releasing element that emits moisture as vapour; and a semi-permeable one-way membrane enclosing the moisture-releasing element that transmits vapour from the moisture-releasing element and substantially blocks the passage of moisture as vapour or liquid to the moisture-releasing element. The moisture-releasing element may emit water vapour, for example.

The use of a one-way membrane that transmits vapour such as water vapour outwards from the moisture-releasing element but not inwards to the moisture-releasing element has a number of advantages. It prevents contamination of the water vapour, which could then be passed to the tobacco, because the moisture-releasing element is unable to absorb anything from its environment. This inability to absorb also means that the moisture- releasing element cannot take flavour from the tobacco products, nor can it acquire any brown staining that can arise from absorption of the atmosphere inside packaging containing tobacco products. Also, the humidifier cannot absorb moisture back from the tobacco after the humidifier has released all its water, so the humidifier cannot contribute to unwanted drying of the tobacco. Thus, there is no need for the user to remember to remove the humidifier from the tobacco environment after use; its prolonged presence cannot be detrimental. The semi-permeable one-way membrane may comprise a reverse osmosis membrane, for example. The semi-permeable one-way membrane may comprise cellulose acetate, polysulphones or polyvinylfluoride.

Many alternatives are available for use as the moisture-releasing element. For example, the moisture-releasing element may comprise water absorbed into a paper matrix incorporating polyacrylamide granules, or water absorbed into one or more alginates, or water absorbed into one or more of micro-crystalline cellulose, ispaghula husk, saturated silica gel, rice, a starch gel, a pectin, natural sponge, synthetic sponge, sepeolite, bentonite or other clay materials, gelatin, agar agar, and modified cellulosic gum.

The moisture-releasing element may further comprise one or more flavourants, fragrances or water-soluble additives that can be carried through the semi-permeable one-way membrane by the water vapour. The user can therefore add their own flavours, scents or other properties to their tobacco products simply by placing such a humidifier inside the packaging or container holding the tobacco products.

In some embodiments, the humidifier may further comprise a breachable outer layer enclosing the semi-permeable one-way membrane, the breachable outer layer being substantially impermeable to the passage of water or water vapour. This allows the humidifier to be supplied separately to the user for use with any tobacco product that needs hydrating as and when required. The breachable outer layer prevents loss of water vapour from the moisture-releasing element until the outer layer is breached, whereupon the water vapour is released to the environment.

The breachable outer layer may be intended to be removed from the semi-permeable oneway membrane before use of the disposable humidifier.

Alternatively, the breachable outer layer may not need to be removed. In such an embodiment, the breachable outer layer may comprise one or more perforations, and one or more sealing members adhered over the perforations to close the perforations, the sealing member(s) being removable from the breachable outer layer to open the - A -

perforations before use of the disposable humidifier. The one or more sealing members may have pull-tabs that are not adhered to the breachable outer layer, to facilitate removal of the sealing members.

To extend the lifetime of the humidifier so that water vapour can be released over a longer period, the humidifier may further comprise at least one further moisture-releasing element enclosed in a semi-permeable one-way membrane, each moisture-releasing element sealed into a separate compartment within the outer layer, each compartment having one or more perforations and one or more removable sealing members adhered over the perforations.

The breachable outer layer may be substantially impermeable to the passage of oxygen. The breachable outer layer may comprise polypropylene, or polyethylene.

The breachable outer layer may have the form of a sachet containing the moisture-releasing element and the semi-permeable one-way membrane. In an alternative, the breachable outer layer may be laminated over the semi-permeable one-way membrane.

Conveniently, the humidifier may further include a visual humidity indicator on an exterior surface of the humidifier. If the humidifier is stored with the tobacco product, the indicator aids the user in determining if the tobacco product would benefit from the addition of some water vapour.

The humidifier may be incorporated into a package for tobacco products.

A second aspect of the invention is directed to a package for tobacco products comprising a disposable humidifier according to the first aspect of the invention.

A third aspect of the invention is directed to a package for tobacco products containing one or more tobacco products and a disposable humidifier according to the first aspect of the invention. The humidifier may be disposed on an interior surface of the package. The package may be a container for cigarettes, cigars or cigarillos, or a receptacle for loose tobacco, for example. The receptacle may be a pouch or a tin.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings in which:

Figure 1 shows a cross-sectional side view through a humidifier according to an embodiment of the invention;

Figures 2A and 2B show respectively a cross-sectional side view and a plan view of a humidifier according to a further embodiment of the invention, having a sachet-style outer layer;

Figures 3A, 3B and 3C show respectively a cross-sectional side view and two plan views of a humidifier according to a further embodiment of the invention, also having a sachet-style outer layer;

Figures 4A, 4B, 4C and 4D show cross-sectional side views and plan views of various examples of humidifiers according to a yet further embodiment, having laminated outer layers; Figure 5 shows a cross-sectional side view of a humidifier according to a still further embodiment;

Figures 6A and 6B show plan views of examples of humidifiers having humidity indicators according to an embodiment of the invention; and

Figures 7, 8 and 9 show examples of tobacco product packaging incorporating humidifiers according to embodiments of the invention.

DETAILED DESCRIPTION

Figure 1 shows a cross-sectional view through a disposable humidifier according to an embodiment of the present invention. In its simplest form, the humidifier 10 comprises a moisture-releasing element 12 enclosed by a semi-permeable membrane 14 which transmits moisturising vapour such as water vapour outwards from the moisture-releasing element to the surrounding environment, as indicated by the arrows. The humidifier 10 is intended for use in packages for tobacco products including cigarette packs and tobacco tins and pouches, so is conveniently a few millimetres thick only, and typically a few centimetres across (probably less than 10 cm), to take up minimum space in the package. It may be any shape, such as rectangular, square or circular. Other dimensions and shapes are not precluded, however.

The moisture-releasing element 12 can be any element that is capable of storing, holding or otherwise providing a quantity or reservoir of moisturising liquid such as water, and giving up the liquid as vapour, preferably at room temperature. Water is a particularly convenient substance for the moisturising of tobacco, but other substances with suitable properties for the necessary storage and vapour release can be used. One example of a suitable material for the moisture-releasing element is a matrix of paper or other material that incorporates crystals or granules of polyacrylamide, and is soaked with water before being enclosed in the membrane 14.

A further example of a suitable moisture-releasing element 12 is one or more alginates.

These materials are linear copolymers produced by various brown algae including seaweed (such as giant kelp) and bacteria (such as Azotobacter species), which are insoluble in water but absorb water quickly. Thus, a quantity of alginate can be soaked with water before being enclosed in the membrane 14. Alginates are fully biocompatible and are used in food stuffs and medicines, so they are a particularly attractive option for use with tobacco products.

Further examples of suitable materials for making the moisture-releasing element 12 include micro-crystalline cellulose, ispaghula husk, saturated silica gel, rice, starch gels, pectins, natural sponge, synthetic sponge, clay materials such as sepeolite and bentonite, gelatin, agar agar, and modified cellulosic gum. Combinations of these materials may also be used. As in the previous examples, a portion of the relevant material is soaked with water (or other evaporable liquid) before enclosure in the membrane 14.

However, the invention is not limited to these particular examples of materials for the moisture-releasing element 12. Any material which has the necessary properties to allow it to absorb an adequate amount of liquid such as water and then release the liquid as vapour by evaporation can be used. Moreover, a separate material for absorbing and holding the liquid may be deemed unnecessary. Instead, a volume of water (or other liquid) may be directly enclosed in the one-way membrane. To avoid any manufacturing difficulties associated with packaging a liquid in a membrane container, the water (or other liquid) could be frozen first, providing a small block of ice that can be wrapped in membrane or inserted into a membrane pouch in the same way as for water-soaked materials, and which will subsequently melt before evaporating.

If water is used, it need not be plain water. An aqueous salt solution may be used instead, which can give control over the evaporation by determining the humidity level of the surrounding environment below which the water vapour will be released. Other nonvolatile liquid ingredients such as glycerol (glycerine) or propylene glycol may alternatively be used; these also control evaporation of the water.

Additionally or alternatively, the moisture-releasing element may also contain one or more water-soluble additives that can be carried through the one-way membrane by the water vapour and hence delivered to the tobacco. These may include flavourants and fragrances. For example, a moisture-releasing element containing menthol can be used to impart a menthol flavour and smell to the tobacco. Vanilla, coffee and other flavours may be similarly provided. In this way, the consumer has a mechanism for flavouring a tobacco product with a flavour of their choice.

The semi-permeable membrane 14 is a one-way membrane that encloses the moisture- releasing element 12 and is arranged such that moisturising vapour can pass out through the membrane 14 from the moisture-releasing element 12 to the surrounding environment (which, in use, includes the tobacco product to be moisturised). However, water vapour and liquid water cannot pass in the opposite direction, i.e. from the surrounding environment to the moisture-releasing element. This keeps the moisture-releasing element free from contaminants which could be picked up from the environment and later released to the tobacco. Also, it prevents the moisture-releasing element from absorbing moisture from inside the tobacco product package after the element has given up most or all of its original water, which could dry out the tobacco. Thus, there is no harm in the humidifier being left in the tobacco product container for an extended period and not removed once it has dried out. The inability of the moisture-releasing element to absorb also means that it cannot take up flavour from the tobacco, which is clearly undesirable, and also that the moisture-releasing element does not acquire an unattractive brown staining that would result if moisture was absorbed from the tobacco. The one-way nature of the membrane does not allow for re-hydration of the moisture-releasing element once used, so the humidifier is intended to be a disposable, single-use humidifier.

The semi-permeable one-way membrane 14 may, for example, comprise a reverse osmosis membrane, such as a synthetic dialysis membrane or other food-grade pharmaceutical membrane. Suitable membrane materials include cellulose acetate, polysulphones or polyvinylfluoride. However, any material with the desired property of one-way transmission of vapour from the moisture-releasing element may be used.

Although Figure 1 shows the one-way membrane 14 entirely surrounding the moisture- releasing element 12, it is not essential that the membrane has the ability to transmit vapour over the whole of its surface. Instead, the moisture-releasing element may be partially covered by a non-permeable layer, with the one-way membrane 14 forming only one side of, or one or more windows in, the covering for the moisture-releasing element 12. For example, one side of the moisture-releasing element 12 may be covered in a non-permeable layer and the other side with a one-way membrane, if it is intended that the humidifier 10 be stuck to the inside surface of a tobacco product package. Further, the ratio of permeable membrane to impermeable membrane can be used to control the rate at which moisturising vapour is given up by the moisture-releasing element, allowing the lifetime of the humidifier to be tailored.

Clearly, a humidifier having the construction shown in Figure 1 will give out water vapour (or other vapour) as soon as it has been fabricated, provided that the humidity of the surrounding environment is not so high as to prevent evaporation. It may be that the humidifier is intended for inclusion in a package of pre-packaged tobacco product to keep the tobacco moist during shipping, storage, display and purchase of the product, so that the product is moist when the consumer opens the package. For this purpose, a humidifier as shown in Figure 1 is adequate if the humidifier is fabricated close to the point of packaging of the tobacco product, or alternatively if a bulk quantity of humidifiers is enclosed in a non-permeable wrapping such as a large plastic bag or sack immediately after fabrication, and kept thus until required at the packaging point.

However, it is also desirable for a humidifier according to the invention to be available separately for a smoker to place into a package of tobacco product after opening, as required to prevent drying of the tobacco or to rehydrate tobacco that has become dry. Also, a humidifier can be supplied inside a package of tobacco product for optional use by the smoker after the package has been opened. In both these cases, it is necessary to prevent the moisture-releasing element from releasing any or most of its moisture until the humidifier is put to use.

To address this, further embodiments of the invention propose to enclose the one-way membrane in a breachable non-permeable outer layer that is substantially impermeable to the passage of water vapour. This will retain the moisture substantially within the moisture- releasing element until such time as the outer layer is opened, removed, broken or otherwise breached, at which time water vapour can escape from the moisture-releasing element to the environment of the humidifier, via the one-way membrane.

Figure 2A shows a cross-sectional view through a humidifier 10 provided with such an outer layer 16. In this example, the outer layer 16 is made from a flexible plastics material configured as a sachet 17 inside which the moisture-releasing element 12 and its enclosing membrane 14 are sealed. The sachet 17 may be of the type commonly used to provide individual portions of condiments in catering establishments, and in this particular example, is intended to be completely removed from the inner components before use of the humidifier, 10. This arrangement provides an outer layer that is very simple and economical to implement, and which uses known packaging technology.

Figure 2B shows a plan view of the humidifier 10 of Figure 2B, showing how the sachet 17 is sealed across each end by sealing lines 18 made for example by plastics welding. Portions of the sachet material extend a short distance beyond the sealing lines 18 and terminate in serrated edges 20, which facilitate tearing open of the sachet 17 for removal of the contents immediately prior to use of the humidifier 10. The outer surface of the sachet 17 may be printed with any desired design, for example, a brand name and with instructions for use of the humidifier 10.

Figure 3A shows a cross-sectional view through a humidifier 10 including a sachet 22 according to a further embodiment. In this example, the sachet 22 is intended to remain in situ around the moisturising element 12 and the membrane 14 during use of the humidifier 10. To allow the water vapour to escape to the environment, the sachet, again made from impermeable material, is provided with at least one aperture or perforation 24, in this case an array of perforations in one surface of the sachet 22. The perforations 24 are covered before use of the humidifier 10 by a removable sealing member 26 which is adhered to the outer surface of the sachet 22 and extends beyond the boundary of the area of perforations to completely seal the sachet 22 to prevent loss of water vapour. When it is desired to use the humidifier 10, the user removes the sealing member 26 by peeling it off from the surface of the sachet 22 to open the perforations 24, thereby breaching the impermeable outer layer of the humidifier 10. To assist with removal of the sealing member 26, optionally the sealing member 26 can be provided with a pull tab 28 extending from an edge of the sealing member 26 and which is not adhered to the sachet 22. The pull tab can therefore be easily grasped and used to peel the sealing member 26 away from the sachet 22.

The sealing member 26 can be adhered to the sachet 22 using single-use adhesive, and disposed off after removal. Alternatively, re-usable or reversible adhesive can be used, allowing the sealing member 26 to be replaced to close the perforations 24 once a desired amount of moisture has been released, thereby allowing moisture remaining in the moisture-releasing element to be retained for future use of the humidifier.

Figure 3B shows a plan view of the humidifier 10 of Figure 3 A, with the sealing member 26 in place. As for the embodiment of Figures 2A and 2B, the sachet can be simply made from flexible plastic formed into a tube and then sealed at both ends along sealing lines 20. In this example, however, there is no need to provide serrated edges because the sachet 22 is not intended to be torn open for removal of the contents. Figure 3 C shows a plan view of the humidifier 10 of Figure 3 A with the sealing member removed to open the perforations 24.

As an alternative to the sachets of the embodiments of Figures 2A and 3A, the breachable outer layer may be provided by laminating the moisture-releasing element 12 and the membrane 14 between two layers of thin plastics material. An outer layer fabricated in this way will not be readily removable from the inner components, so it should be provided with an aperture or perforations closed with a removable sealing member similar to those described with respect to Figure 3A.

Figure 4A shows a cross-sectional view of such a humidifier 10. The outer layer 16 comprises upper and lower layers 30 of thin plastics material laminated over the moisture- releasing element 12 and the membrane 14. The various parts are shown spaced apart for clarity but in reality will be in close contact owing to the laminating process, giving a substantially flat product. The upper layer 30 of the outer layer 16 has one or more apertures 24 cut therein, which are covered by the sealing member 26 adhered to the surface of the outer layer 16.

A design such as a brand name or instructions for use can be printed onto the outside surface of the outer layer, before or after lamination. Alternatively, if the plastics material is transparent, an additional layer of paper or other thin printable material can be included between the membrane 14 and the lower layer 30 of laminate material; this will be visible through the outer layer.

Figure 4B shows a cross-sectional view of a laminated humidifier 10 that includes such an additional printed layer 32.

Figure 4C shows a plan view of a laminated humidifier 10 in which the apertures 24 have the form of two parallel elongate slits in the outer layer 16. These are indicated by dotted lines and are covered in this illustration by a single sealing member 26 having a pull tab 28.

Figure 4D shows an alternative example that also has apertures 24 in the form of two parallel elongate slits, but which is provided with two sealing members 26, one for each slit. This allows the user to choose between different levels of moisture release, by uncovering one or both slits.

In any embodiment having sealing members, the openings in the outer layer may be small perforations or larger apertures, may be any number and be arranged in any pattern or shape on one or more sides of the humidifier. Any number of sealing members can be provided to allow a greater or lesser number of perforations or apertures to be opened at any one time. In the present disclosure, the terms "perforation" and "aperture" are used interchangeably and are to be understood as having the same meaning of an opening in the outer layer through which water vapour from the moisture-releasing element can escape to the environment.

Further in this regard, two or more separate moisture-releasing elements may be provided within a single outer layer. If individual sealing lines are provided in the outer layer to divide the moisture-releasing elements into separate sealed compartments within the outer layer, and individual apertures/perforations and associated sealing members are provided for each moisture-releasing element, the life of the humidifier can be extended by allowing moisture to be released from just one moisture-releasing element at a time, the other(s) staying completely sealed until required.

Figure 5 shows a cross-sectional view of a humidifier having two moisture-releasing elements 12 and an outer layer 16 in the form of a sachet 22, which is sealed along a sealing line 33 positioned between the two elements 12. Each element 12 has its own perforations 24 and sealing member 26.

The invention is not limited to impermeable outer layers in the form of sachets or provided as laminates. Any configuration can be employed that will seal the moisture-releasing element and its membrane against vapour release and which can be removed or otherwise breached or opened to allow vapour release when required. The breachable outer layer can be fabricated from any suitable material, typically a plastics material. The type of material will depend in part on the design of the outer layer, for example whether it is a sachet or a laminated structure. For laminated structures, polypropylene is suitable, for example. Polyethylene may also be used for the outer layer, particularly for sachets. In view of the disposable nature of the humidifier, an outer layer that is recyclable and/or biodegradable may be preferred.

To assist the user in determining when a humidifier according to the present invention should be employed, embodiments of the invention include a humidity indicator. If the humidifier is stored inside the packaging of the tobacco product, the indicator can then show when it should be used. The indicator can be any type of compact humidity measuring device or sensor that gives a visual indication of the humidity level. A convenient example is a cardboard or paper device comprising one or more sensor areas of water-sensitive material that absorb moisture from the atmosphere and change colour according to whether the humidity is above or below some threshold value. A range of sensor areas having different threshold values may be provided, to give a visual humidity scale from which the user can make a decision as to whether his tobacco product is appropriately moist; if the atmosphere becomes to dry the humidifier can be activated by breaching the impermeable outer layer. Alternatively, a single sensor area can be provided to give one threshold humidity measurement so that the humidifier can be activated if the humidity drops below the threshold. The threshold can be selected at a useful level for humidity at which tobacco is satisfactorily moist.

For a humidifier including an outer layer which is not removed for use, the humidity indicator can be positioned on the outside surface of the outer layer, and can therefore give a humidity measurement both before and after opening of the apertures or perforations. Thus the humidifier can be activated when the moisture level becomes too low, and then closed or removed from the packaging when the level becomes high enough. For a humidifier in which the outer layer is to be removed before use, the humidity indicator will be located on the outside surface of the outer layer, but will not then be available for use after the humidifier has been activated by removal of the outer layer.

Figure 6A shows a plan view of a humidifier 10 with a laminated outer layer 16 similar to those of Figures 4A-4C, and a humidity indicator 34 positioned on its back surface (i.e. the surface opposite to the surface having the apertures/perforations). The humidity indicator 34 has a plurality of sensor areas 36. Figure 6B shows a plan view of a humidifier 10 having a sachet-style outer layer 16 which is to be removed before use of the humidifier (similar to that in Figures 2A and 2B). A humidity indicator 34 having a single sensor area 36 is provided on the outside surface of the outer layer 16.

As mentioned above, humidifiers according to the present invention can be supplied as products in their own right for insertion in a package or container of tobacco product by the user, in which case the humidifier should have a breachable impermeable outer layer. Alternatively, humidifiers can be included inside the packaging of pre-packaged tobacco products. In the latter case, the humidifier can be according to the embodiment of Figure 1, so that it maintains the moisture level of the tobacco before the package is opened by the user, or it can include a breachable outer layer so that it is available for use after the package is opened if the user wants to raise the moisture level. For either of these possibilities, the humidifier can either be included loose inside the packaging, or it can be incorporated into the packaging, for example by being glued to an interior surface of the packaging. Such a humidifier is widely applicable to many types of tobacco packaging.

Figure 7 shows a perspective view of the top part of a pack 38 for smoking articles such as cigarettes or cigars. The pack 38 has a hinged flip-top lid 40 which has a humidifier 10 according an embodiment of the present invention adhered to the inside surface of its upper face, where it can be easily seen and accessed by a user. Note that the smoking articles which would be supplied in the pack 38 have been omitted from the Figure in the interests of clarity.

Figure 8 shows a cross-sectional side view of a pouch 42 containing loose tobacco 44 for rolling or pipe smoking. The pouch 42 comprises a bag-like container portion 46 for holding the tobacco 44, and a closure portion 48 in the form of a flap that folds over and wraps around the container portion to keep the pouch 42 closed and the tobacco 44 moist. A humidifier 10 is adhered to the upper part of the inside surface of the rear wall of the container portion 46.

Figure 9 shows a perspective view of a tin 50 for holding loose tobacco 44, the tin having a lid 52 with a humidifier 10 on its inside surface. Note that in each of the examples of Figures 7, 8 and 9 the humidifier 10 may or may not have a breachable outer layer.

Various other features may be included in the humidifiers described thus far. For example, the moisture-releasing element may take the form of a gel configured to release moisture at a controlled rate. Gels of this type for use in humidifiers are described in our co-pending application GB 0710784.0 "Controlled moisture release humidifier for use with tobacco products", filed in the United Kingdom on 5th June 2007. As another example, the humidifier may include an additional sealed compartment containing a supercoolable salt hydrate solution that can be activated to crystallise and release heat to the moisture- releasing element, thereby increasing the rate of moisture release by evaporation. Humidifiers comprising such "heat releasing gels" are described in our co-pending application GB 0710776.6 "Heatable humidifying device for use with tobacco products", filed in the United Kingdom on 5th June 2007. Further, the breachable membranes described herein may be used in other configurations of humidifiers, and are not limited to use with humidifiers that include a semi-permeable one-way membrane.

Claims

1. A disposable humidifier for use with tobacco products comprising: a moisture-releasing element that emits moisture as vapour; and a semi-permeable one-way membrane enclosing the moisture-releasing element that transmits vapour from the moisture-releasing element and substantially blocks the passage of moisture as vapour or liquid to the moisture-releasing element.

2. A humidifier according to claim 1 , in which the moisture-releasing element emits water vapour.

3. A humidifier according to claim 1 or claim 2, in which the semi-permeable one-way membrane comprises a reverse osmosis membrane.

4. A humidifier according to claim 1 or claim 2, in which the semi-permeable one-way membrane comprises cellulose acetate, polysulphones or polyvinylfluoride.

5. A humidifier according to any one of claims 1 to 4, in which the moisture-releasing element comprises water absorbed into a paper matrix incorporating polyacrylamide granules.

6. A humidifier according to any one of claims 1 to 4, in which the moisture- releasing element comprises water absorbed into one or more alginates.

7. A humidifier according to any one of claims 1 to 4, in which the moisture-releasing element comprises water absorbed into one or more of micro-crystalline cellulose, ispaghula husk, saturated silica gel, rice, a starch gel, a pectin, natural sponge, synthetic sponge, sepeolite, bentonite or other clay materials, gelatin, agar agar, and modified cellulosic gum.

8. A humidifier according to any preceding claim, in which the moisture-releasing element further comprises one or more flavourants, fragrances or water-soluble additives that can be carried through the semi-permeable one-way membrane by the vapour.

9. A humidifier according to any preceding claims, in which the humidifier further comprises a breachable outer layer enclosing the semi-permeable one-way membrane, the breachable outer layer being substantially impermeable to the passage of water or water vapour.

10. A humidifier according to claim 9, in which the breachable outer layer is intended to be removed from the semi-permeable one-way membrane before use of the disposable humidifier.

11. A humidifier according to claim 9, in which the breachable outer layer comprises one or more perforations, and one or more sealing members adhered over the perforations to close the perforations, the sealing member(s) being removable from the breachable outer layer to open the perforations before use of the disposable humidifier.

12. A humidifier according to claim 11, in which the one or more sealing members have pull-tabs that are not adhered to the breachable outer layer, to facilitate removal of the sealing members.

13. A humidifier according to claim 11 or claim 12, and further comprising at least one further moisture-releasing element enclosed in a semi-permeable one-way membrane, each moisture-releasing element sealed into a separate compartment within the outer layer, each compartment having one or more perforations and one or more removable sealing members adhered over the perforations.

14. A humidifier according to any one of claims 9 to 13, in which the breachable outer layer is further substantially impermeable to the passage of oxygen.

15. A humidifier according to any one of claims 9 to 14, in which the breachable outer layer comprises polypropylene.

16. A humidifier according to any one of claims 9 to 14, in which the breachable outer layer comprises polyethylene.

17. A humidifier according to any one of claims 9 to 16, in which the breachable outer layer has the form of a sachet containing the moisture-releasing element and the semipermeable one-way membrane.

18. A humidifier according to any one of claims 9 to 16, in which the breachable outer layer is laminated over the semi-permeable one-way membrane.

19. A humidifier according to any one of the preceding claims, in which the disposable humidifier further includes a visual humidity indicator on an exterior surface of the humidifier.

20. A humidifier according to any one of the preceding claims, in which the disposable humidifier is incorporated into a package for tobacco products.

21. A package for tobacco products comprising a disposable humidifier according to any one of claims 1 to 19.

22. A package for tobacco products containing one or more tobacco products and a disposable humidifier according to any one of claims 1 to 19.

23. A package for tobacco products according to claim 21 or claim 22, in which the disposable humidifier is disposed on an interior surface of the package.

24. A package for tobacco products according to any one of claims 21 to 23, in which the package is a container for cigarettes, cigars or cigarillos.

25. A package for tobacco products according to any one of claims 21 to 23, in which the package is a receptacle for loose tobacco.

26. A package for tobacco products according to claim 25, in which the receptacle is a pouch or a tin.