WO2007059590A1

WO2007059590A1 - A wicking fabric and a method for manufacturing the same

Info

Publication number: WO2007059590A1
Application number: PCT/AU2006/001794
Authority: WO
Inventors: Anthony Pierlot; Ronald James Denning; Laurence Michael Staynes; Ian Blanchonette; Geoffrey Robert Stewart Naylor
Original assignee: Commonwealth Scientific And Industrial Research Organisation
Priority date: 2005-11-25
Filing date: 2006-11-27
Publication date: 2007-05-31

Abstract

The present invention relates to fabric and a method for making a fabric, wherein an inner or first face of the fabric is partly or entirely hydrophobic relative to an outer or second face and liquid can be drawn through hydrophobic regions of the inner or first face to the outer or second face by wicking. The relative hydrophobicity of the inner or first face is provided by either one or a combination of hydrophobic or hydrophilic agents, wherein: i) the hydrophobic agent is confined to the inner or first face or has penetrated the inner or first face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the inner or first face toward the outer or second face without forming part of the outer or second face; or ii) the hydrophilic agent is confined to the outer or second face or has penetrated the outer or second face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer or second face toward the inner or first face without forming part of the inner or first face.

Description

_ i _

A WICKING FABRIC AND A METHOD FOR MANUFACTURING THE SAME

FIELD OF THE INVENTION

The present invention relates to a single or multi- layered fabric having a capacity to wick liquid from an inner face of the fabric to an outer face and a method for making the fabric. Ordinarily, it is envisaged that the fabric will be used to wick moisture away from the skin of a person wearing the fabric. However, in some applications the fabric may also be reversed such that the fabric may be used to wick moisture toward the skin of a person.

BACKGROUND TO THE INVENTION

Fabric according to the present invention is suitable for use in a wide range of applications. For example, base layer garments made from the fabric can draw sweat away from the skin to leave the wearer cool, dry and comfortable. In another example the fabric can be used as a bandage or dressing in medical applications for removing exudate or bodily fluids from a wound, or in the reverse configuration to apply moisture or medication to a wound while leaving the outer face dry.

Modern fabrics for sporting or activewear garments are designed to wick moisture or sweat away from the surface of the skin to the outer surface of the garment where the moisture can evaporate and thereby keep the wearer cool and dry. Fabric that contains hydroscopic fibres such as wool, cotton or regenerated cellulose also provide additional comfort, or at least perceived additional comfort on the basis that these fibres also absorb and desorb water vapour, which are known as the buffering properties of the fabric. To some extent this minimises the wearer feeling wet in the event of sudden changes in the relative humidity of the microclimate inside the garment, particularly at the beginning of strenuous exercise when the body starts to perspire. Wool, for example, will absorb around 15% of its mass as water vapour at 65% relative humidity and up to 35% of its mass at 100% relative humidity. Therefore, as the relative humidity of the surroundings changes, hydroscopic fibres absorb and desorb water vapour to maintain an equilibrium and thereby provide a buffering effect for the wearer.

Moisture buffering is related to the hydroscopic properties of the fibre and the capacity of the internal structure to absorb moisture. The absorption of water by a fibre is usually referred to as regain and is high for wool, cotton and regenerated cellulose (rayon, viscose etc) but low for synthetic fibres like polyester and polypropylene. The ability of a fabric to wick moisture is related to the surface energy of the fibre surface, fibre diameter and shape, and the fabric structure. Most synthetic fibres have low surface energy so that fabrics produced from these fibres repel liquid water or are hydrophobic unless a surface active agent (eg detergent) is included in the liquid. An untreated wool fibre has a waxy lipid layer that coats the entire fibre surface making the surface hydrophobic. This lipid layer is partially removed when the wool is^' shrink resist treated using the chlorine/Hercosett process and is replaced with a water swelling polymer (Hercosett) and a softener. A common softener used in the chlorine/Hercosett process is based on alkylamines and the treated fibre is hydrophobic similar to an untreated fibre.

In order for a fabric to wick moisture away from one face of the fabric to the other face, a wicking gradient must be established. For example, this can be achieved readily in a two layer fabric structure by knitting a fabric where one side is predominately constructed from a hydrophobic yarn while the other is constructed from a more hydrophilic yarn. In this context the hydrophilicity of the yarn is its affinity for liquid water and this is a balance between the properties of: the fibre surface, namely fibre type and surface treatment; the capillary spaces in the yarns, namely fibre diameter and yarn twist; and fabric structure, namely yarn count and cover factor. Numerous examples of these types of fabric are available in the market place, for example, Sportwool™.

In a practical sense, 2-layered fabrics are often limited by the following factors.

• Fabric weight:- 2 layered fabrics are often of a double knit construction comprising 2 single jersey fabrics knitted back-to-back. Such double knit constructions impose a lower limit on fabric weights which are problematic when lighter weight fabrics with good cover factor are preferred.

• Finished fabric properties:- more complex double knit structures, particularly those comprising non-thermoplastic fibres, are less dimensionally stable and also tend to have relatively poor stretch and recovery compared to many single layer knitted structures.

• Cost:- the requirement for fine yarns in a double layer knit structure compared to similar weight single knit constructions invariably means that 2-layered fabrics are relatively expensive fabrics.

There have been a number of proposals put forward that minimize some of these limitations mentioned. For example, US application 2002/0064639 (serial number 7,008,887) describes a single layered fabric structure in which a hydrophobic material is applied to the inner face of a hydrophilic base fabric in a discontinuous manner to create both hydrophobic and hydrophilic regions on the inner face. The hydrophobic regions repel liquid and the hydrophilic regions form channels or wicking windows that extend from the inner face to the outer face through which liquid is wicked. According to our experience, one of the disadvantages of the fabric described in the above US application is that when the fabric approaches saturation, liquid may leak in a reverse direction through the wicking windows toward the inner face, reducing comfort for the wearer.

SUMMARY OF THE PRESENT INVENTION

The present invention is based on the surprising result that a fabric having a wicking gradient capable of transporting liquid from a first face, such as an inner face to a second face, such as an outer face. The fabric is formed by applying either one or a combination of hydrophobic agent(s) to the first or inner face and/or hydrophilic agent(s) to the second or outer face of the fabric in a manner such that the hydrophobicity of the fabric does not extend to the second or outer face of the fabric and the hydrophilicity of the fabric does not extend to the first or inner face of the fabric.

According to the present invention there is provided a woven, knitted or non- woven fabric, wherein an inner or first face of the fabric is partly or entirely hydrophobic relative to an outer or second face and liquid can be drawn through hydrophobic regions of the inner or first face to the outer or second face by wicking, and wherein the fabric is treated when partially or fully assembled with either one or a combination of hydrophobic or hydrophilic agents such that the fabric has a structure in which: i) the hydrophobic agent is confined to the inner or first face or has penetrated the inner face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the inner or first face toward the outer face without forming part of the outer or second face; or ii) the hydrophilic agent is confined to the outer or second face or has penetrated the outer or second face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer or second face toward the inner or first face without forming part of the inner or first face. It is within the scope of the present invention that the hydrophobic agent is confined to an outer face of the fabric or penetrated the outer face without forming part ' of the inner face and/or the hydrophilic agent is confined to the inner face or penetrated the inner face without forming part of the outer face. ^•

Although it is within the scope of the present invention that the hydrophobic and/or hydrophilic properties of the fabric may be imparted to the fabric while the fabric is partially assembled, it is preferred that the hydrophobic and/or hydrophilic properties of the fabric be imparted when weaving, knitting or other non- woven assembly techniques have been completed. In other words, when the fabric is assembled into a fully formed fabric.

According to one embodiment, it is preferred that the fabric be a multilayered fabric.

The term "multilayered fabric" throughout this specification embraces: i) a fabric having two or more layers that may be independently manufactured and thereafter placed face to face and optionally bonded together; and ii) a fabric having two or more distinct layers in a single body or unitary structure of fabric, wherein each layer of the fabric is identified or characterised by a particular feature or property such as the type of the fibres or threads contained in the fabric, and the structure of the yarns or threads in each layer of the fabric such as whether the fibres are knitted or woven.

According to another embodiment, it is preferred that the fabric be a single layered fabric.

Throughout this specification, the term "single layered fabric" embraces any fabric whether partially or entirely assembled, wherein when fully assembled, that fabric has any one or a combination of individual threads, yarns, filaments or fibres are assembled so as to extend between inner and outer faces of the fabric.

An advantage of the present invention is that the inner hydrophobic face of the fabric will essentially remain dry to touch and minimise the flow of liquid in a reverse direction, that is, from the outer face to the inner face.

When in use, it is preferred that a water drop applied to the hydrophobic inner face will bead momentarily and then be drawn to the outer face where it spreads. It is preferred that the hydrophilic agent extend from the outer face toward the inner face and substantially cross at least half the thickness of the fabric.

It is preferred that the hydrophobic agent extend from the inner face toward the outer face without substantially crossing at least half the thickness of the fabric.

In other words, it is preferred that the hydrophobic agent extend from the inner face toward a central point substantially centred between the inner and outer faces without substantially crossing the central point. In contrast, it is preferred that the hydrophilic agent substantially cross the central point.

There are various techniques and methods available for measuring the extent to which the hydrophobic and hydrophilic agents have migrate through the fabric. One of the most practical techniques for checking the extent of migration into the fabric is by the hydrophobic and/or hydrophilic agent containing a coloured dye so that the degree of migration can be visually observed. Alternatively staining the fabric with an aqueous dye solution will preferentially stain the hydrophilic layer of the fabric.

The fabric may be made from any suitable fibre or filament type including synthetic, man-made, or natural fibres. For example and without limitation, the fabric may be made from one or a blend of the following: proteinaceous fibres such as wool, silk and hair; cellulosic fibres such as cotton, bamboo, linen, synthetic fibres such as polypropylene, polyester, nylon, rayon, acrylic, and man-made fibres such as the regenerated cellulosics such as viscose and fibres produced from biomaterial feedstocks such as polylactic acid.

In the situation where the fabric is made predominantly of hydrophilic fibres, for example, when the fabric includes at least 50 percent cotton fibres, it is preferred that the inner face of the fabric be treated with a hydrophobic agent. In this situation, it may not be necessary for the fabric to have been treated with a hydrophilic agent.

Although it is within the scope of the present invention that the inner face may only have a hydrophobic coverage of 50 percent or less, it is preferred that the inner face be treated with a hydrophobic agent over at least 80 percent of the inner face. It is even more preferred that the inner face of the fabric be treated with a hydrophobic agent over at least 90 percent.

It is still even further preferred that the hydrophobic agent be substantially continuously present over the inner face of the fabric.

Irrespective of the hydrophobic coverage, it is intended that liquid be able to be drawn through the hydrophobic regions to the outer face of the fabric.

In the situation where the fabric is made predominantly of hydrophobic fibres, for example, when the fabric includes at least 50 percent wool, polyester or polypropylene fibres, it is preferred that the outer face of the fabric be treated with a hydrophilic agent. In this situation, it may not be necessary for the fabric to have been treated with a hydrophobic agent.

It is preferred that the fabric has a thickness ranging from 0.1 to 10mm and even more preferably, the fabric has a thickness ranging from 0.2 to 5mm. In the situation involving a preferred thickness ranging from 0.1 to 10mm, the central point of the fabric will range from approximately 0.05 to 5mm from the inner or outer faces for the fabric and in the situation where the fabric thickness is over the more preferred thickness range 0.2 to 5mm, the central point of the fabric is approximately 0.1 to 2.5mm from either the inner and outer faces. The above thicknesses do not take into account surface fuzz or fluff that may occur on the inner and outer faces.

It is preferred that the fabric has a wicking ratio greater than 2: 1._. Details of a wicking test procedure are set out below on page 13.

It is preferred that the hydrophobic agents be any one or a combination of fluorocarbons, hydrocarbons, silicones and waxes.

Commercial hydrophobic agents that may be suitable include the following.

• Rucostar EEE a fluorocarbon resin with polymeric, hyperbranched dendrimers in a hydrocarbon matrix from Rudolf Chemie that is normally applied at 30- 50g/L with a 60-80% wet pickup. • Rucostar DDD a fluorocarbon resin with polymeric, hyperbranched dendrimers in a hydrocarbon matrix from Rudolf Chemie that is normally applied by exhaustion methods at 4-6% on weight of sample.

• Ruco-Dry DHY a water-repellent based on polymeric, hyperbranched dendrimers in a hydrocarbon matrix from Rudolf Chemie that is normally applied at 80-130g/L with a wet pick-up of 60-80%.

• Ruco-Phob PZN a paraffin compound from Rudolf Chemie that is normally applied at 60-100g/L with a wet pick up of 60-80%.

• Nuva TTC a fluorocarbon from Clariant that is normally applied by either pad application at 15-70g/L or 1.5-7% on weight of samples for exhaust methods.

• SM8709 a silicone emulsion for handle modifying of textiles from Dow Corning/Toray that is normally applied at 2-10% on weight of sample (solids component).

It is preferred that the hydrophilic agents include functional groups that include but are not limited to any one or a combination of carboxylates, silicates, sulfonates, sulfates, hydroxyl and phosphates.

Commercial hydrophilic agents that may be suitable include the following. • Rucofin SIQ-G a polysiloxane compound from Rudolf Chemie that is normally applied by both pad application at 10-40g/L or exhaust application and a range of 1-4% on weight of sample.

• Primal 2348 an aqueous acrylic from Rohm and Haas normally applied by pad application. • Primal HA-8 a self-crosslinking acrylic emulsion from Rohm and Haas that is normally applied by pad application at 10-40g/L and a wet pickup of 70%.

• SA4188 a hydrophilic aminosilicone microemulsion from Flexichem normally applied at 10-40g/L and a wet pickup of 70%.

• SA4132 a hydrophilic silicone microemulsion from Flexichem normally applied at 10-40g/L and a wet pickup of 70%.

Irrespective of the type of agent present in the fabric, it is preferred that the fabric contains from 0.5 to 20Og of hydrophobic agent per kilogram of fabric, more preferably from 1 to 100 g/kg of fabric and most preferably from 2 to 25 g/kg of fabric. . It is also preferred that the fabric contains from 0.5 to 200 g of hydrophilic active agent per kilogram of fabric, more preferably from 1 to 100 g/kg of fabric and most preferably from 2 to 25 g/kg of fabric.

According to the present invention there is provided a single or multilayered fabric, wherein an inner face of the fabric is partly or entirely hydrophobic relative to an outer face and liquid can be drawn through hydrophobic regions of the inner face to the outer face by wicking, and wherein when the fabric is assembled into a fully formed fabric, the fabric is treated with either one or a combination of hydrophobic or hydrophilic agents, the fabric has a structure in which: i) the hydrophobic agent is confined to the inner face or has penetrated the inner face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the inner face toward the outer face without forming part of the outer face; or ii) the hydrophilic agent is confined to the outer face or has penetrated the outer face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer face toward the inner face without forming part of the inner face.

According to the present invention there is also provided a method of making or treating a fabric so that it is capable of wicking liquid from an inner or first face of the fabric to an outer or second face of the fabric, the fabric having a single layered or a multi-layered construction and includes either one or a combination of the following steps: a) treating the inner or first face of the fabric with a hydrophobic agent under conditions such that the hydrophobic agent is confined to the inner or first face or is allowed to penetrate the inner or first face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the inner or first face toward the outer or second face without forming part of the outer or second face; or b) treating the outer or second face of the fabric with a hydrophilic agent under conditions such that the hydrophilic agent is confined to the outer second face or is allowed to penetrate the outer or second face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer or second face toward the inner first face without forming part of the inner or first face.

Although steps a) and b) may be carried out using any suitable technique such as inkjet printing, screen printing, spraying, pad application, doctor blade or lick- roller, it is preferred that step a) and/or b) be carried out using a foam applicator. An .

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example, of a suitable foam applicator is that which is commercially available from Gaston System under the trade name CFS (Chemical Foam Systems).

The extent to which the hydrophobic and hydrophilic agents penetrate or ^• migrate into the fabric is dependent on a number of factors, such as:

• the period of time or residence time over which the foam is allowed to soak into the fabric - such is a function of the speed of the fabric through the applicator;

• pressure in the applicator head that applies the foam to the fabric, the higher the pressure the greater the extent of migration into the fabric; and _ • the weight of the foam applied to the fabric, which is a function of the speed of the fabric through the applicator, the speed and thickness of the foam applied to the fabric, the viscosity of the foam applied to the fabric, the pressure of the foam, the water content and flow rate of the foam.

In the situation where either the hydrophobic agent is applied to the inside of the fabric in accordance with step a) without step b), it is preferred that the hydrophobic agent be applied by way of foam application. In the situation where the . hydrophilic agent is applied to the outside of the fabric in accordance with step b) without step a) it is preferred that the hydrophilic agent be applied by way of foam application.

In the situation where a fabric is treated in accordance with both steps a) and b), it is possible for the hydrophilic and hydrophobic agents to be applied in one of the following combinations: • the hydrophobic agent is applied by pad application and the hydrophilic agent is applied by foam application in accordance with step b);

• the hydrophilic agent is applied by foam application and the hydrophobic agent is applied by foam application in accordance with step a);

• the hydrophobic agent is applied by foam application in accordance with step a) and then dried and cured, followed by the hydrophilic agent is then applied by ' foam application in accordance with step b) and dried and cured; or alternatively

• the hydrophilic agent is applied by foam application in accordance with step b) and dried and cured, followed by the hydrophobic agent is then applied by foam application in accordance with step a) and dried and cured.

The method of the present invention may also include any one or a combination of the preferred features of the fabric mentioned above such as: • the extent to which the hydrophobicity or hydrophilicity of the fabric extends through the fabric;

• the coverage of the hydrophobic or hydrophilic agent to the inner and outer faces of the fabric; • the fabric being made of particular fibre types; and

• the possible varieties of hydrophobic or hydrophilic agents.

In order for the fabric to retain its wicking properties over the course of laundering cycles, the hydrophobic and/or hydrophilic agents will need to be fixed in position to the fibres by way of chemical bonding such as covalent bonding, ionic bonding, dispersion forces or by way of physical encapsulation possibly followed by crosslinking. Depending on the nature of the hydrophobic or hydrophilic agents used and the type of fibres included in the fabric, it is preferred that the method also include either one or a combination of drying or curing steps. These steps increase the durability of the wicking treatment to washing and laundering.

According to the present invention there is also provided a garment including the fabric either separately from or in combination with any one of the preferred features of the fabric described above. The garment includes but is by no means limited to underwear, outerwear such as pants and rain coats, jumpers, shirts, dressings and medical bandages. Ordinarily, the inner and outer faces of the fabric will be arranged so as to form part of the inner and outer parts of the garment so that the garment is adapted to wick liquid in a direction away from the skin of the person. However in some applications the fabric may be reversed so that the inner and outer faces of the fabric form part of the outer and inner parts of the garment respectively. In this situation, the garment can wick moisture inwardly toward the person wearing the . garment and is suitable for applicatiqns such as treating skin burns where moisture and medication can be applied to a wound without removing the bandage and dressing while leaving the outside of the bandage dry.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the ^• following drawings: of which:

Figure 1 is a schematic illustration showing a perspective view of a section of the fabric, wherein an inner face of the fabric has been treated with a hydrophobic agent and liquid is capable of being wicked through the fabric in the direction of the arrows; - ii -

Figure 2 is a schematic illustration showing a perspective view of a section of the fabric, wherein the outer face of the fabric has been treated with a hydrophilic agent and liquid is capable of being wicked through the fabric in the direction of the arrows; Figure 3 is a schematic illustration showing a perspective view of a section of a fabric, wherein the inner face of the fabric has been treated with a hydrophobic agent and the outer face of the fabric has been treated with a hydrophilic agent and liquid is capable of being wicked through the fabric in the direction of the arrows; and

Figures 4 is a schematic drawing of an apparatus for applying hydrophobic and/or hydrophilic agents to the fabric in the form of foam.

DETAILED DESCRIPTION

The embodiments shown in Figures 1 to 3 have a number of identical or similar features and as a matter of convenience the same reference numerals have been used throughout the drawings and description to identify these features.

Figure 1 is an example of a hydrophilic base fabric that is made from hydrophilic fibres or filaments including, but by no means limited to, wool fibre treated to be hydrophilic, cotton, other types of cellulosic fibres, regenerated cellulosic, hydrophilic polyester or blends thereof. The fabric is of a single layered construction and has an inner and outer face that is generally identified by reference numerals 10 and 11 respectively. A dashed line 12 between the inner and outer faces 10 and 11 has been drawn at approximately the centre of the fabric. The hydrophilic fabric has been treated with a hydrophobic agent that has penetrated the inner face 10 and is located on the inner face 10 and extends towards but does not cross the central line 12. The hydrophobic agent is schematically represented in Figure 1 by the diagonal lines 13.

Although not shown in Figures 1 to 3, the hydrophobic treatment on the inner face 10 is continuously applied across the inner face or only across a portion. In any event, the hydrophobic treatment is such that the liquid can be drawn through the hydrophobic treatment to the outer face in the direction of arrows A.

Figure 2 is an example of a single layered hydrophobic base fabric that is made from hydrophobic fibres or filaments including, but by no means limited to, wool, polyester, polypropylene or blends thereof. The fabric has been treated with a hydrophilic agent that has penetrated the outer face 11 and is located on outer face 11 and extends toward but does not form part of the inner face 10. The hydrophilic agent is schematically represented by small crosses 14 that extend from the outer face 11 and substantially crosses the central line 12. The inner face 10 is relatively hydrophobic in comparison to the outer face 11 by virtue of the nature of the fibres used to make the fabric and liquid is able to be drawn through the hydrophobic inner face 10 in the direction of arrows A to the outer face 11.

Figure 3 is an example of a single layered base fabric containing a blend of hydrophobic and hydrophilic fibres. The fabric has been treated with a hydrophobic agent 13 that has penetrated the inner face 10 such that the hydrophobicity of the fabric extends from the inner face 10 toward to the central dashed line 12 but does not substantially cross the dashed line 12. The fabric has also been treated with a hydrophilic agent 14 that extends from the outer face 11 of the fabric and across the central dashed line 12 but does not form part of the inner face 10 of the fabric. Again, liquid is able to be drawn through the hydrophobic inner face 10 to the outer face 11 in the direction of arrows A.

Figure 4 is a schematic diagram of an apparatus suitable for applying hydrophobic or hydrophilic agents in foam form to the fabric. An example of an apparatus suitable for foam application is the apparatus by GASTON SYSTEMS that is commercially available under the trade name CFS. The apparatus shown in Figure 4 comprises two foam head applicators 20 for applying foam to inner and/or outer faces of the fabric 21. Each foam head 20 is connected to a foam generator 22 to which: i) air is fed via air compressor 23; and ii) a liquor containing a hydrophobic agent and, optionally surfactant, are fed via pump 24. The foam generators 22 produce a continuous supply of fine but variable bubble size homogeneous foam that is fed into the foam heads 20 via a pump 25. If needed, additional air can be supplied to the foam heads 20 to: increase air content, increase flow rate or increase pressure of the foam applied to the fabric 21.

^■ . The apparatus also includes two pairs of rollers 26 that form a nip through which the fabric 21 passes and an oven 27 for drying the foam applied to the fabric 21. The broken line 28 in Figure 4 represents that the oven 27 may be separated from the foam head applicators 20. The rate at which the fabric 21 is fed through the apparatus can be controlled by the speed of revolution of the pairs of rollers 26. The fabric may also be fed through the apparatus in individual sheets, or preferably as a continuously web that is stored in rolls 29 at the front and back ends of the apparatus. Although the apparatus includes two foam heads 20 that are capable of applying foam simultaneously to opposite side of the fabric 21, in the situation where both hydrophobic and hydrophilic agents are applied to opposite sides of the fabric it is envisaged that the hydrophobic and hydrophilic agents will be applied to the fabric on separate passes through the apparatus where a single foam generator is used. In other words, one of the agents will be applied to the fabric 20 on one pass through the apparatus and the other agent will then be applied to the fabric 20 on another pass through the apparatus. Ideally the agent applied to the fabric on the first pass will be dried before the fabric is run through the apparatus on the second occasion. Where two foam generators are available, simultaneous application of the hydrophobic and hydrophilic agents to opposite sides of the fabric can be achieved in a single pass, as shown in Figure 4.

In addition, in the situation where one of either hydrophobic or hydrophilic agents are applied to the fabric and the after testing of the fabric, it is determined that insufficient agent has been applied to the fabric it is possible for further agent to be applied to the fabric by again feeding the fabric through the apparatus.

The extent to which the hydrophobic and hydrophilic agents penetrate or migrate into the fabric is dependent on a number of factors, such as:

• the period of time or residence time over which the foam is allowed to soak into the fabric - such is a function of the speed of the fabric through the applicator; • pressure in the foam or applicator head that applies the foam to the fabric, the higher the pressure the greater the extent of migration into the fabric; • the weight of the foam applied to the fabric, which is a function of the speed of the fabric through the applicator;

• the density of the foam and concentration of hydrophobic and hydrophilic agents in the foam; and

• the properties of the fabric including the weight of the fabric and capillary spaces between the fibres of the fabric which effect penetration and migration of foam into the fabric.

In any event, in order for hydrophobic and hydrophilic agents to coat the inner and outer surfaces adequately and provide the desired level of penetration through the thickness of the fabric, ideally the fabric contains from 0.5 to 40Og of hydrophobic and/or hydrophilic agent per kilogram of fabric. Preferably the fabric contains from 1 to 20Og of hydrophobic and/or hydrophilic agent per kilogram of fabric and even more preferably from 2 to 50g/kg of fabric.

WICKING TEST PROCEDURE The wicking performance of a fabric can be demonstrated and quantitatively measured by a differential wicking test. In particular, the test involves placing a drop of water measuring 50 microlitres from a pipette on the inner face or skin side of the fabric. After the water has been absorbed entirely by the fabric (this is usually less then 30 seconds for most fabrics), weighed pieces of blotting paper are placed either side of the fabric and the assembly laid flat with a 1.Okg weight having a base diameter of 70mm is placed on top of the paper and fabric assembly. After 30 seconds the weight is removed, the blotting papers reweighed and the mass of water ■ absorbed by each determined. A wicking ratio defined as the mass of water extracted from the outer face divided by the mass of water extracted by the inner fabric face can then be calculated. An average wicking ratio can be determined by repeating this procedure 3 times and then repeated a further 3 times with the water being placed on the opposite face of the fabric.

EXAMPLES A method of treating a fabric so as to have wicking properties will now be described with reference to the following non-limiting examples, of which:

Examples 1 to 6 relate to the application of hydrophobic agents by spraying;

Examples 7 and 8 relate to the application of hydrophobic agents by foam. application; and

Example 9 relates to the application of hydrophilic and hydrophobic agents.

Example 1 A pure wool fabric knitted from chlorine/Hercosett shrink resist treated yarns (80-tex, two folded, single jersey knitted structure with a coverfactor of 1.32) was scoured with 2g/l Softinol 90 at pH ~3 and 65⁰C for 35 minutes then rinsed and neutralised with 2ml/l ammonia for lOminutes at 4O⁰C, then rinsed, to remove all presence of the hydrophobic softener that is normally applied as part of the shrink resist process. A drop of water placed on the surface of the fabric spreads and is absorbed by the fabric in less than 1 second, ie., the base fabric is rendered hydrophilic. Fabric that has not had the softener removed is hydrophobic and a water droplet remains on the surface for greater than 30 seconds. A solution of a silicone emulsion, Dow Corning/Toray SM8709 at lOg/1 in water is sprayed onto the inner face of the fabric at a rate of 200ml/m² using an industrial air spraying gun to render the inner face hydrophobic. The fabric was then dried at 8O⁰C for 10 minutes and later cured in an oven for 10 minutes at HO⁰C. To aid visualisation of some of the treatments a water soluble dye may be added to the spaying solution.

In terms of performance, the fabric was cooled to room temperature and a drop of water placed on the inner hydrophobic surface was absorbed within 2 to 5 seconds. A wicking ratio of greater than 50:1 was achieved. After washing the fabric according to Woolmark TM31 to 5x5A wascator cycles the wicking ratio remained at more than 7:1.

Example 2 This example followed the same basic procedure as Example 1 to provide a hydrophilic base fabric. However, rather than treating the fabric with a solution of a silicone emulsion, Dow Corning/Toray SM8709, the fabric underwent a hydrophobic treatment involving treating the fabric with Nuva TTC, a fluorocarbon based product from Clarient, at a concentration of 20g/l. The fabric was subsequently dried and cured as described above.

In terms of performance, the fabric had a wicking ratio after treatment of 6:1.

Example 3

This example is substantially the same as Example 2, save for the hydrophobic treatment involved treating the fabric with Rucostar EEE, a fluorocarbon based product from Ruldof Chemie, at a concentration of lOg/1 with the water pH adjusted to ~ 3.5 with 60% acetic acid.

In terms of performance, the fabric had a wicking ratio after treatment of 5:1. When the fabric was washed in accordance with the washing procedure described above in relation to Example 1, the wicking ratio was reduced to 3:1.

Example 4

This example is substantially the same as Example 1, save for the hydrophobic treatment involved treating the fabric with Ruco-Dry DHY, a hydrocarbon from based product Ruldof Chemie, at a concentration of lOg/1 with the water pH adjusted to ~ 3.5 with 60% acetic acid.

In terms of performance, the fabric has a wicking ratio after treatment of 8:1. When the fabric was washed in accordance with the washing procedure described above in relation to Example 1, the wicking ratio was reduced to 4: 1.

Example 5

This example is substantially the same as Example 1, save for the fabric which was a single jersey polyester fabric (1/24 Ne count) knitted to a cover factor of 1.32 and prior to treatment with a hydrophobic agent, the fabric was rendered hydrophilic by pre-treatment with a hydrophilic agent. The fabric was purchased from Spotlight retailers, who are supplied by George Black wholesalers.

In terms of performance, the fabric had a wicking ratio of 6: 1 after treatment with the hydrophobic.

Example 6 This example is substantially the same as Example 2, save for the fabric which was a single jersey cotton fabric (1/20 Ne count) with a weight of 170g/m²

In terms of performance, the fabric has a wicking ratio after treatment of 70:1.

. Example 7

A 100% cotton Birdseye knit structure with a fabric weight of 233g/m² was treated on the inner face of the fabric by top foam application using a Gaston Systems CFS Foam applicator. A liquor was made comprising a hydrophobic agent in the form of 50g/l of SM8709 (Dow Corning/Toray) and a surfactant in the form of 1.5% solution of Ricofoam 227 (Ruldof Chemie). The liquor was then foamed in the CFS applicator at a flow rate of 40 cc/min and an air flow rate of 1.8 1/min which gave a blow ratio of air to liquid phase of approximately 45. The foam was then applied by single sided application to the fabric with the fabric running through the applicator at three different speeds, namely 3.3m/min, 6.6m/min 9.9m/min. The pick up for the three samples was calculated as a ratio of the amount of mass of the liquor on the sample after the treatment to the mass of the sample before treatment as 11.07%, 5.5% and 3.7% respectively. In other words, the treated fabric for each respective speed contained approximately 5.54g, 2.75g and 1.85g of hydrophobic agent product per kilogram of fabric. The three samples were then dried in a mini stenter at 16O⁰C with a retention time of 4 minutes.

In terms of performance, the wicking ratio of the untreated fabric was

1.5:1 (outer face to inner face) while the treated fabric gave results of 4:1 (outer face to inner face), 4: 1 and 5:1 respectively.

Example 8 A double knit polyester outer and cotton inner fabric with a weight of 223 g/m was treated on the cotton side by top foam application using a Gaston Systems CFS Foam applicator. A liquor was then made from a hydrophobic agent in the form of a 50g/l of SM8709 and a surfactant in the form of a 1.5% solution of Ricofoam 227, both of which were obtained from Ruldof Chemie. The liquor was then foamed in the CFS applicator at a liquor flow rate of 30cc/min and an air flow rate of 1.21/min which gave a blow ratio of air to liquid phase of approximately 40. The foam was then applied by single sided application to the fabric at a speed of 6m/min to give a single sided pick up of 4.7%. The sample was then dried in a mini stenter at 16O⁰C with a retention time of 4 minutes. The treated fabric contained approximately 2.35g of hydrophobic agent per kilogram of fabric.

In terms of performance, the wicking ratio of the untreated fabric was 0.08:1 (poly:cotton, outeπinner) while the treated fabric gave a result of 0.52: 1 substantially reducing the moisture in the inner face of the fabric giving a wicking improvement factor (wif) of 6.5 where the wicking improvement factor is the normalised mass of water (inner face normalised tol) retained in the outer face of the treated fabric divided by the normalised mass of water retained in the outer face of untreated fabric.

The method outlined in Examples 8 and 9 was carried on six different fabric types as set out in Table 1 below Table 1

The column in Table 1 entitled WICKING provides the wicking ratio for an untreated fabric. Fabric types 1, 3, 4, 5 and 6 are examples of single layered fabric, whereas fabric type 2 is an example of the multi-layered fabric.

The six fabric types listed in the Table 1 were subject to treatments in accordance with the method outline in Examples 7 and 8. Table 2 on pages 19 and 20 provides a summary of the conditions including the agents and make of liquor used to treat the fabric, pick up of the treated fabric and wicking properties. As can be seen from Table 2, the treated fabric exhibits improved wicking properties that can be used to draw through the fabric.

Example 9 . ^'

This example follows basically the same procedure as for example 1 except a hydrophilic softener Rucofin SIQ-G obtained from Ruldof Chemie was applied to the fabric via pad; 1.47% ows at 59% pickup, the sample was then dried at 105⁰C and had a wicking ratio of 1 : 1 prior to the application of the hydrophobic agent being sprayed on as in example 1. The hydrophobic agent used was Rucostar EEE and Rucoweb at levels of 40g/L and 5g/L respectively. This gave wicking results of 2: 1 (outside: inside).

In addition, upon completion of the fabric being treated in accordance with Examples 1 to 9 and in accordance with those shown in Table 2, cross-sections of the fabric were analysed and the distribution of the hydrophobic and hydrophilic agents was observed as conforming with the general principles of the present invention. Specifically, in the situation where the liquor used to treat the fabric includes a hydrophobic agent, the hydrophobic agent is confined to a first face of the fabric, such as the inside face of a garment or has penetrated the inside face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the first or inside face toward the second or outer face without forming part of, or included in, the second face. In addition, in the situation where the liquor contains a hydrophilic agent, the ■ hydrophilic agent is confined to what would be the second or outside face of the garment or has penetrated the second face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the second face toward the first face without forming part of, or included in, the first face.

Those skilled in the art of the present invention will appreciate that many modifications and variations may be made to the preferred embodiments described with reference to Figures 1 to 3, the apparatus shown in Figure 4, examples 1 to 8, and the result and conditions shown in Table 2 without departing from the spirit and scope of the present invention.

Table 2

CD

m m m

2

Table 2 cont'd

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A woven, knitted or non- woven fabric, wherein an inner face of the fabric is partly or entirely hydrophobic relative to an outer face and liquid can be drawn 5 through hydrophobic regions of the inner face to the outer face by wicking, and wherein the fabric is treated when partially or fully assembled with either one or a combination of hydrophobic or hydrophilic agents such that the fabric has a structure in which: i) the hydrophobic agent is confined to the inner face or has penetrated the inner face such that the hydrophobic agent and the hydrophobicity of the fabric extends 0 from the inner face toward the outer face without forming part of the outer face; or ii) the hydrophilic agent is confined to the outer face or has penetrated the outer face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer face toward the inner face without forming part of the inner face.

^*5 2. The fabric according to claim 1, wherein the fabric is a multi-layered fabric.

3. The fabric according to claim 1, wherein the fabric is a single layered fabric. 0

4. The fabric according to any one of the preceding claims, wherein the hydrophilic agent extends from the outer face toward the inner face and substantially cross at least half the thickness of the fabric.

5 5. The fabric according to any one of the preceding claims, wherein the hydrophobic agent extends from the inner face toward the outer face without ^■ substantially crossing at least half the thickness of the fabric.

6. The fabric according to any one of the preceding claims, wherein the 0 fabric includes synthetic, man-made, or natural fibres.

7. The fabric according to any one of the preceding claims, wherein the fabric is made from one or a blend of the following:: proteinaceous fibres such as wool, silk and hair; cellulosic fibres such as cotton, bamboo, linen; synthetic fibres such as 5 polypropylene, polyester, nylon, rayon, acrylic, and man-made fibres such as the regenerated cellulosics such as viscose and fibres produced from biomaterial feedstocks such as polylactic acid.

8. The fabric according to any one of the preceding claims, wherein when the fabric is made predominantly of hydrophilic fibres, the hydrophobic agent is confined to the inner face, or penetrated the inner face, and the hydrophilic agent is absent from the fabric.

9. . The fabric according to any one of the preceding claims, wherein the hydrophobic agent is confined to, or penetrated, 50 percent of the inner face.

10. The fabric according to any one of the preceding claims, wherein the hydrophobic agent is confined to, or penetrated, 90 percent of the inner face.

11. The fabric according to any one of the preceding claims, wherein the hydrophobic agent is substantially continuously present over the inner face of the fabric.

12. The fabric according to any one of the preceding claims, wherein when" the fabric is made predominantly of hydrophobic fibres, the hydrophilic agent is confined . to the outer face, or penetrated the outer face, and the hydrophobic agent is absent from the fabric.

13. The fabric according to any one of the preceding claims, wherein the fabric has a thickness ranging from 0.1 to 10mm

14. The fabric according to any one of the preceding claims, wherein the fabric has a thickness ranging from 0.2 to 5mm.

15. The fabric according to any one of the preceding claims, wherein the fabric has a wicking ratio (outer face to inner face) greater than 2:1.

16. The fabric according to any one of the preceding claims, wherein the hydrophobic agent is any one or a combination of fiuorocarbons, hydrocarbons, silicones and waxes.

17. The fabric according to any one of the preceding claims, wherein the hydrophilic agent has functional groups that include any one or a combination of carboxylates, silicates, sulfonates, sulfates, hydroxyl and phosphates.

18. The fabric according to any one of the preceding claims, wherein, the fabric contains from 0.5 to 20Og of hydrophobic agent per kilogram of fabric.

19. The fabric according to any one of the preceding claims, wherein the fabric contains from Ig to lOOg of hydrophobic agent per kilogram of fabric.

20. The fabric according to any one of the preceding claims, wherein the fabric contains 2 to 25 g of hydrophobic agent per kilogram of fabric.

21. The fabric according to any one of the preceding claims, wherein the fabric contains from 0.5 to 20Og of hydrophilic agent per kilogram of fabric.

22. The fabric according to any one of the preceding claims, wherein the fabric contains from 1 to lOOg of hydrophilic agent per kilogram of fabric.

23. The fabric according to any one of the preceding claims, wherein the fabric contains from 2 to 25 g of hydrophilic agent per kilogram of fabric.

24. A method of treating a fabric so that it is capable of wicking liquid from an inner face of the fabric to an outer face of the fabric, the fabric includes either one or a combination of the following steps: a) treating the inner face of the fabric with a hydrophobic agent, wherein the hydrophobic agent is confined to the inner face or penetrates the inner face such that the hydrophobic agent and the hydrophobicity of the fabric extends from the inner face toward the outer face without forming part of the outer face; or b) treating the outer face of the fabric with a hydrophilic agent, wherein the hydrophilic agent is confined to the outer face or penetrates the outer face such that the hydrophilic agent and the hydrophilicity of the fabric extends from the outer face to the inner face without forming part of the inner face.

25. The method according to claim 24, wherein steps a) or b) are carried out using a foam applicator or a spraying applicator.

26. The method according to claim 25, wherein steps a) and b) involve: • the hydrophobic agent being applied by pad application and the hydrophilic agent being applied by foam application in accordance with step b); • the hydrophilic agent being applied by foam application in accordance with step b) and the hydrophobic agent being applied by foam application in accordance with step a);

• the hydrophobic agent being applied by foam application in accordance with step a) and then dried and cured, followed by the hydrophilic agent being applied by foam application in accordance with step b); or

• the hydrophilic agent being applied by foam application in accordance with step b) and dried and cured, followed by the hydrophobic agent being then applied by foam application in accordance with step a).

27. The method according to any one of claims 24 to 26, further including either one or a combination of drying or curing steps to cure the hydrophobic and/or hydrophilic agents.

28. The method according to any one of claims 24 to 27, wherein the fabric is a multi-layered fabric.

29. The method according to any one of claims 24 to 27, wherein the fabric is a single layered fabric.

30. The method according to any one of claims 24 to 29, wherein when the fabric is made predominantly of hydrophilic fibres, step a) involves treating the inner face of the fabric with a hydrophobic agent without step b) occurring.

31. The method according to any one of claims 24 to 30, wherein step a) involves treating at least 50 percent or less of the inner face of the fabric.

32. The method according to any one of claims 24 to 31, wherein step a) involves treating at least 90 percent or less of the inner face of the fabric.

33. The method according to any one of claims 24 to 32, wherein step a) involves the hydrophobic agent being applied substantially continuously over the inner face of the fabric.

34. The method according to any one of claim 24 to 33, wherein when the fabric is made predominantly of hydrophobic fibres, step b) involves treating the outer face of the fabric with a hydrophilic agent without step a) occurring. W

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35. The method according to any one of claims 24 to 34, wherein the hydrophobic agent is any one or a combination of fluorocarbons, hydrocarbons, silicones and waxes.

5

36. The method according to any one of claims 24 to 35, wherein the hydrophilic agent has a functional group that includes any one or a combination of carboxylates, silicates, sulfonates, sulfates, hydroxyl and phosphates.

0 37. The method according to any one of claims 24 to 36, wherein step a) involves from 0.5 to 20Og of hydrophobic agent being applied to a kilogram of fabric.

38. The method according to any one of claims 24 to 36, wherein step a) involves from 1 to lOOg of hydrophobic agent being applied to a kilogram of fabric. 5 .

39. The method according to any one of claims 24 to 38, wherein step a) involves from 2 to 25g of hydrophobic agent being applied to a kilogram of fabric.

40. The method according to any one of claims 24 to 39, wherein step b) 0 involves from 0.5 to 200g of hydrophilic agent being applied per kilogram of fabric.

41. The method according to any one of claims 24 to 39, wherein step b) involves from 1 to lOOg of hydrophilic agent being applied per kilogram of fabric.

5 42. The method according to any one claims 24 to 39, wherein step b) involves from_.2 to 25g of hydrophobic agent being applied per kilogram of fabric.

43. The method according to any one of claims 24 to 42, wherein step b) involves treating the outer face such that the hydrophilic agent extends from the outer 0 face toward the inner face and substantially cross at least half the thickness of the fabric.

44. The method according to any one of claims 24 to 43, wherein step a) involves treating the inner face such that the hydrophobic agent extends from the inner 5 face toward the outer face without substantially crossing at least half the thickness of the fabric.

45. The method according to any one of claims 24 to 44, wherein the hydrophobic agent used in step a) is any one or a combination of fϊurocarbons, hydrocarbons, silicones and waxes.

46. The method according to any one of claims 24 to 45, wherein the hydrophilic agent has functional groups that include any one or a combination of carboxylates, silicates, sulfonates, sulfates, hydroxyl and phosphates.

47. A garment including the fabric according to any one of claims 1 to 24, wherein the inner and outer faces of the fabric form part of inner and outer parts of the garment such that the garment is adapted for wicking liquid in a direction toward the outer part of the garment.

48. A garment including the fabric according to any one claims 1 to 24, wherein the inner and outer faces of the fabric form part of outer and inner parts of the garment such that the garment is adapted for wicking liquid in a direction toward the inner part of the garment.