GB2446866A

GB2446866A - Cut resistant yarn

Info

Publication number: GB2446866A
Application number: GB0703322A
Authority: GB
Inventors: Kit Blake
Original assignee: WYKES INTERNAT Ltd
Current assignee: WYKES INTERNAT Ltd
Priority date: 2007-02-21
Filing date: 2007-02-21
Publication date: 2008-08-27
Also published as: WO2008102130A1; GB0703322D0

Abstract

A cut resistant yarn comprises a core 2 retained by a retention wrap 5 and having a tenacity wrap 6 to define a cut resistant combination. The cut resistant combination is associated with a textured wrap 7 at least to one side of the tenacity wrap for tactility. The core preferably comprises a multi-ply such as stainless steel core surrounded by glass-fibre or multiple strands side by side or wound about each other. The retention wrap may comprise two layers of fibres wound around the core in a counter helix to each other to hold the core in compression. The tenacity wrap may comprise fibres wound around the retention wrap or vie versa, and may deform into the retention wrap under impact. The textured wrap may achieve rub retention when moved against other parts of the textured wrap to limit fraying, such as when formed into a knitted product. The textured wrap may be dyed or may incorporate an anti-microbial agent such as silver, or may incorporate rubber elements. The textured wrap may be sandwiched between the retention and tenacity wraps but is preferably an outer layer. The yarn is used for making protective garments such as gloves.

Description

Yarn and Garments made from Yarn The present invention relates to yarns

and more particularly to cut-resistant yarns utilised in forming garments for bodily protection in respect of cut injuries.

It will be appreciated in certain occupations and activities there is a danger of cut injury from sharp edges, burrs and knives. In such pursuits it is known to provide garments such as gloves, aprons and smocks for protection.

These garments protect individuals from cuts but also inmost situations must be sufficiently light to allow the activity to be performed. Thus with respect to factory workers lifting sheet metal or other components it is important to provide protection but that protection should be relatively light in weight to allow dexterous activities and be relatively cheap in view of the number of garments required. It is also understood that these factory workers may consider these gloves disposable particularly when they seemed to be dirty.

Previous garments for cut resistance have included chain-mail type gauntlets and gloves etc which are clearly too cumbersome for most activities.

It is also know to provide garments made with a cut-resistant yarn comprising a core of glass fibre and/or steel surrounded by a retention wrap to protect the core from splintering and kinks during a knitting process to form a garment and then generally a tenacity wrap with a cut resistant fibre wound around the exterior of the retention wrap purely to create a cut resistant combination. By their nature tenacity wraps can be relatively shear and smooth and therefore in situations which require dexterity and a good hand grip may be considered unsuitable. Such high tenacity yarns which are abrasion resistant but smooth include extended chain polyethylene fibres such as Dyneema TM and liquid crystal polymer fibres (Vectran). Other tenacity yarns such as aramide fibres (Kevlar) are not smooth so have grip but poor abrasion resistance. Both of these fibres generally are only available in limited colours which tend to be light such as yellow or white or gold resulting in garments formed from these fibres looking soiled prematurely as a result of becoming dirty quickly.

In accordance with aspects of the invention there is provided a cut resistant yarn comprising a resilient core retained by a retention wrap and the cut resistant yarn having a tenacity wrap to define a cut resistant combination, the cut resistant combination is associated with a textured wrap at least to one side of the tenacity wrap for tactility.

Also in accordance with aspects of the present invention there is provided a protective garment comprising a knit of cut resistant yarn as described above.

Normally, the textured wrap provides an external, surface for the yarn.

Alternatively, the textured wrap is provided between the retention wrap and the tenacity wrap.

Typically, the resilient core comprises glass fibre and/or a metal strand.

Typically, the metal strand is stainless steel. Generally, the resilient core comprises a multi-ply. Generally, the multi-ply comprises two plies one of glass fibre and one of a metal strand. Possibly, the multi-ply comprises strands of material side by side. Alternatively, the multi-ply comprises strands of material wound about each other.

Generally, the retention wrap comprises fibres that are wound about the resistant core. Generally, the fibres are in a helix about the resistant core.

Typically, the retention wrap comprises two layers of fibres respectively wound in a counter helix to each other. Typically, the retention wrap is formed from one or more of the following nylon, polyester, polypropylene, cotton, wool, viscose or blends/mixtures thereof. Possibly, the retention wrap holds the resistant core in compression. Possibly, the degree of compression is specified in order to act as a cushion for the tenacity wrap.

Possibly, the tenacity wrap is formed from an extended chain polyethylene and/or liquid crystal polymer fibres and/or aramide fibres.

Possibly, the tenacity wrap comprises fibres wound about the retention wrap or vice versa. Typically, the tenacity wrap is arranged to deform under impact into the retention wrap. Typically, the tenacity wrap is formed from Kevlar TM or Dyneema TM or Vectran TM Typically, the textured wrap is arranged to facilitate tacticity in order to achieve rub retention when moved against other parts of the textured wrap to limited fraying. Possibly, the textured wrap allows retention of a dye. Typically, the textured wrap is formed by air jet texturisation or a false twist texturing process. Possibly, the textured wrap incorporates an anti-microbial agent.

Possibly, the anti-microbial agent is silver. Possibly, the textured wrap incorporates rubber elements. Typically, the textured wrap is formed from a high tenacity polyester, high tenacity polypropylene or high tenacity nylon.

Aspects of the present invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a schematic longitudinal cross section of a yarn in accordance with aspects to the present invention; Figure 2 is a cross section of a fibre in accordance with aspects to the present invention; Figure 3 is a schematic illustration of a cross section of a fibre in accordance with aspects to the present invention when contacted with a sharp edge; and: Figure 4 is a schematic illustration of a garment formed utilising a yarn in accordance with aspects to the present invention.

Providing cut resistant yarns which have a light weight is advantageous in respect of garments such as gloves utilised in industry and for other pursuits. Typically, protective garments are formed through knitting. It will be appreciated such forming and processing are liable to kink and bond the yarn such that glass fibres utilised to provide a resistant core will splinter during the machining processes whilst metal strands such as stainless steel will kink.

Glass fibre fragments and kinked metal strands which extend to the surface of the garment are an irritation to wearers of garments such as gloves and may cause micro abrasions and scratching. In such circumstances provision of retention wraps around the resistant core is known in order to retain these glass fibre and metal strands to reduce irritation to the wearer. Furthermore in order to protect the retention wrap and facilitate further cut resistance it is known to apply a tenacity wrap comprising high strength fibres wound about the combination of the resistant core and retention wrap. Such a tenacity wrap as indicated improves cut resistance and also protects the retention wrap from excessive fraying in use.

Garments are designed to allow and facilitate tasks which will need a tactile feel. In order to achieve tactility in a garment such as a glove there needs to be some grip in the yarn whilst remaining substantially abrasive resistant. It will be understood that prior tenacity wraps in addition to providing additional cut resistance can also reduce abrasion upon the retention wrap.

Unfortunately, the nature of some of the fibres e.g., extended chain polyethylene or liquid crystal polymer fibres from which tenacity wraps are formed means they are relatively sheer and therefore having a reduced ability with regard to providing grip for a user. Alternatively, some aramide fibres for the tenacity wrap may provide grip but have poor abrasive resistance.

Figures 1 and 2 provide schematic illustrations repectably longitudally and across a yarn in accordance with aspect to the present invention. The yarn 1 comprises a resilient core 2 formed from a glass fibre 3 and a metal strand 4. It will be appreciated that the resilient core 2 may be formed solely from a glass fibre or a metal strand but generally it is advantageous to provide the core 2 as a multi-ply of strands as illustrated in Figures 1 and 2. These strands m y he side by side or alternatively with the strands wound around each other (not shown). The core 2 provides the bulk of cut resistance protection when engaged by a blade, sharp edge or burr but is likely to kink or splinter when overly bent as a result of knitting or other forming processes with regard to a garment.

In order to retain splintered and kinked resistant cores within the yarn and formed garments, a retention wrap 5 is provided about the cut resistant core 2. This retention wrap 5 generally comprises a nylon sleeve or more typically strands of nylon fibre tightly wrapped about the core 2 in order to constrain release of splintered and kinked strands 3, 4 of the core 2 as a result of garment forming processes. The retention wrap 5 may be formed from any textile yarn such as nylon as indicated but also polyester, acrylic, polypropylene, cotton, wool, viscose and blendslmixtures thereof.

Generally, two strands of nylon are wound in a helix about the core 2.

The strands will be arranged in a counter helix to each other to constrain and retain the core strands 3, 4 in place if splintered or kinked as a result of the garment manufacturing processes.

It will be appreciated that the material and in particularly the strands from which the retention wrap 5 is made can be pre-tensioned in order to place some compressive load upon the core 2 and in particularly strands 3, 4 for association and retention. Such compression in the retention wrap 5 will create a degree of elasticity and cushion in support of a tenacity wrap 6 presented there about.

The tenacity wrap 6 as indicated is formed from a high strength fibre such as an extended chain Polyurethylene (DyneemaTM) or an aramide fibre Keviar or liquid crystal polymer fibres (Vectran). The tenacity wrap again typically comprises a wound strand extending in to a helix about the yarn 1 and as indicated provides additior.a! cut resistance as we!! as possihly abrasion resistance for the yarn 1. The nature of such high strength fibres is that they can be relatively sheer and therefore have reduced tacticity whilst alternative fibres such as aramide fibres may be more tactile but have limited abrasion resistance. These fibres are also only availa.ble in generally light colours such as yellow, gold or white which tends to become soiled more easily. Soiled garments it will be appreciated are more likely to be disposed of by an operative prior to a real requirement for disposal. White, gold or yellow garments are generally disadvantageous in industrial environments.

In accordance with aspects to the present invention a tactile textured wrap is associated with yarn generally as an outer surface for the yarn 1. This textured wrap is formed from high tenacity fibres such as polyester, polypropylene or nylon textured in order to provide a high tacticity for the yarn 1 which will then be transferred to a garment formed in accordance with aspects to the present invention. The tactile textured wrap extends around the tenacity wrap 6 to one side and as previously generally takes the form of a fibre strand extending in a helix to protect the remainder of the yarn 1. The textured wrap may be sandwiched between the retention wrap and the tenacity wrap but more normally, as illustrated, will be an outer layer. The advantage of the tacticity wrap 7 is as indicated that it allows a garment such as a glove formed from the yarn 1 by a knitting process to have a tactile feel as well as abrasion resistance. The wrap 7 allows different colours to be provided. The fibre from which the tacticity wrap 7 is formed can be dyed during fibre formation process or once the fibre or garment has been formed.

The wrap 7 is advantageously formed from any texturised fibre in which for example an air jet is blown towards the fibre in order to provide volume and therefore tacticity to the fibre wrapped around the core 2, retention wrap 5 and tenacity wrap 6. The process of texturisation is known to persons skilled in the technology and effectively enhances the roughness of the fibre creating a softer and less sheer nature. The fibres to form the wrap 7 are generally nylon or other fibres as indicated above. An alternative, forming process is a false twist texturising process as also known to persons skilled in this technology.

As indicated above the yam I in accordance with aspects of the present invention will be knitted into a garment form. In such circumstances should the tactile wrap 7 in accordance with aspects to the present invention become cut it will be appreciated that fraying of that wrap 7 will be limited in view of the mutual grip at cross over of fibres in the knit formation. The nature of the cross over of fibres engaging each other will resist slippage and therefore retain fraying to the inter fibre margins of the knit. The underlying tenacity wrap 6, retention wrap 5 and core 2 will remain so that only a portion of slippery and slick wrap 6 will be exposed.

The yarn 1 in accordance to aspects of the present invention can be formed into garments such as gloves which are substantially slash- proof to burrs, sharp edges and knives. It will be appreciated pointed objects will generally still penetrate by displacing the inter knit of the new knit pattern. In such circumstances garments in accordance with aspects to the present invention may include t-shirts and underwear to provide protection from slash injuries.

B

Figures 1 and 2 show yarn 1 in accordance with aspects to the present invention in a schematic form. The thicknesses of the coe 2, wraps 5, 6 and 7 will be dependant on operational requirements. Generally, as indicated the core 2 is the base cut resistance for the yarn 1 and therefore its relative size within the yarn defines the degree of cut resistance but none the less in accordance to aspects of the current invention yarns 1 will generally be of relatively fine nature and therefore the space in between the cores 2 in a knit formation for a garment will be relatively small. It will also be understood that the thickness and nature of the materials from which the core 2 are formed 1 0 will significantly determine the flexibility of the yarn 1 and so suitability for knitting or other forming processes.

Normally the retention wrap 5 as indicated will comprise one or two helixs of nylon or similar fibre material at a desired tension to create compression on the core 2. By compression fragments and kin king of the core elements, (glass fibre 3 and metal strand 4) will be contained. The retention wrap 5 also due to the nature of the material and the tightness of the wind will create elasticity and a cushion between the core 2 and the tenacity wrap 6.

This elasticity will allow deformation under a slash or impact blow from a blade or sharp edge. In such circumstances as depicted in Figure 3 a sharp edge 10 will engage a yarn 1 through the wrap 7. This i/rap 7 may be cut by the edge particularly if there is movement sideways in a direction arrow heads A. Nevertheless, the blade 10 will engage the tenacity wrap 6 presented upon the retention wrap 5. The wrap 6 will not be easily cut and so will deform the retention wrap 5 as depicted in Figure 3. This will present a greater surface area to the blade 10 spreading cutting load over that length or area to enhance cutting resistance. Eventually the fibres of the wrap 6 will be cut and the blade 10 will relatively easily cut the nylon or similar fibres of the retention wrap 5 until there is engagement with the resistant core 3, 4 (core 2 in Figurel). lt will be appreciated that generally a large number of fibres 1 will be formed into a knitted structure as described above and therefore the blade 10 will extend over a large number of fibres such that the collective effect of all the engaged fibres resists cutting both initially and in engagement with the tenacity wrap 6 and the resistant core 2 (Figure 1).

It will be appreciated a balance needs to be struck between tension created by the retention wrap 5 being too flaccid, such that although there will be deformation in response to engagement to the blade 10 but this will lead to a relatively light retention of the core 3, 4 and over tension. Generally it is preferable to provide a robust tight helix wrap of nylon or similar fibres for the retention wrap 5 in order to ensure that the splinters and kinks of the core 3, 4 are retained for user comfort.

As indicated above yarns in accordance to aspects to the present invention are particularly useful in respect of forming garments such as gloves. Figure 4 provides a schematic illustration of a glove incorporating a yarn in accordance to aspects to present invention. The glove 20 is knitted such that it is not necessary to cut the fabric from which the glove 20 is formed and therefore it is seamless. The knitting process as indicated will include bending and twisting of the yarns and therefore the general construction of the cut resistant combination comprising the core 2 (glass fibre 3/metal strand 4) along with retention wrap 5 and tenacity wrap 6 will ensure a core resistant nature is achieved. By providing a textured wrap about this core cut resistant combination tactile feel as well as a dyed colour definition for the glove 20 can be achieved.

It will be understood that the glove 20 may be utilised as with other garments in a range of environments. These environments include with respect to assembly of components in a factory where panels may have sharp edges or burrs and therefore the gloves will protect operatives with respect to moving these panels. Alternatively, the gloves may be used in situations where hygiene is required and there is a danger of cutting with knives. The ability to provide a tactile field for lifting and manipulating components through use of a garment made from yarn in accordance to aspects to present invention has advantages. It will also be appreciated that the ability to provide a colour identifier to the yarn means that gloves for different situations can be more readily identified. For example, it may be possible to provide gloves of different colours for different uses or to confirm hygienic conditions. Similarly, to ensure appropriate use of gloves different colours may be applied for different shifts or otheiwise. The textured outer wrap may also have fibres which incorporate anti-microbial activity or are associated with an anti-microbial agent such as silver.

To further improve grip it will be appreciated that rubber dots or features may be imprinted upon the glove once formed. Thus for example a palm area and finger tips of the glove 20 as depicted in Figure 4 may incorporate rubber dots to further enhance tactile feel. The rubber dots are secured by the provision of a tactile surface to the yarn 1. The rubber dots may not be adequately be secured directly to a tenacity wrap formed from high strength fibres such as Keviar or extended chain polyethylene.

As indicated above generally fibres from which the tenacious wrap is formed will have a light yellow, or gold or white colour. It such circumstances by having a more vibrant or more contrasting colour such as black, areas of damage in the garment can be more readily noted by exposure of the underlying tenacious wrap 6 with its white or yellow nature or vice versa.

It will be appreciated that provision of a cut and abrasion resistant yarn for garments is a desired objective. The yarn has a cut resistant combination of a core (metal stud/glass fibre) and retention wrap along with a tenacity wrap to at least partially protect the retention wrap. It is possible, particularly with a tenacity wrap formed from an at least partially tactile fibres such as Kevlar, to arrange for the textured wrap to be sandwiched between the retention wrap and the tenacity wrap rather than as ao outer layer. Thus, abrasion resistance will be retained, even if the tenacity wrap frays, by the underlying textured wrap so giving a shift in the balance of abrasion resistance to grip to favour more abrasion resistance.

Modification and alterations to aspects to the present invention wilt be appreciated by those skilled in the art. Thus for example the resistant core 2 may be formed from several strands in a multi-ply of fibre alass or metal such as stainless steel alt associated together. The retention wrap may comprise 0 fibres of the same type, same dernier or otherwise or combinations of several fibres wound in a helix about the core. The relative thickness of the fibres forming the core 2 and wraps 5, 6, 7 may be adjusted to achieve the most appropriate yarn 1 dimensions.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims 1 A yarn comprising a resilient core retained by a retention

wrap and the cut resistant yarn having a tenacity wrap to define a cut resistant combination, the cut resistant combination is associated with a textured wrap at least to one side of the tenacity wrap for tactility.

2 A yarn as claimed in claim I wherein the textured wrap provides an external surface for the yarn.

3 A yarn as claimed in claim I wherein the textured wrap is provided between the retention wrap and tenacity wrap.

4 A yarn as claimed in any of claims 1, 2 or 3 wherein the resilient core comprises glass fibre and/or a metal strand.

A yarn as claimed in claim 4 wherein the metal strand is stainless steel.

6 A yarn as claimed in any preceding claim wherein the resilient core comprises a multi-ply.

7 A yarn as claimed in claim 6 wherein the multi-ply comprises two plies one of glass fibre and one of a metal strand.

8 A yam as claimed in claim 6 or claim 7 wherein the multi-ply comprises strands of material side by side.

9 A yarn as claimed in claim 6 or claim 7 wherein the multi-ply comprises strands of material wound about each other.

A yarn as claimed in any preceding claim wherein the retention wrap comprises fibres that are wound about the resistant core.

11 A yam as claimed in claim 10 wherein the fibres are in a helix about the resistant core.

12 A yarn as claimed in claim 10 or claim 11 wherein the retention wrap comprises two layers of fibres respectively wound in a counter helix to each other.

13 A yarn as claimed in any of claims 10 to 12 wherein the retention wrap is formed from one or more of the following nylon, polyester, polypropylene, cotton, wool, viscose or blends/mixtures thereof.

14 A yarn as claimed in any of claims 10 to 13 wherein the retention wrap holds the resistant core in compression.

A yarn as claimed in claim 14 wherein the degree of compression is specified in order to act as a cushion for the tenacity wrap.

16 A yarn as claimed in any preceding claim wherein the tenacity wrap is formed from an extended chain polyethylene and/or liquid crystal polymer fibres and/or aramide fibres.

17 A yarn as claimed in any preceding claim wherein the tenacity wrap comprises fibres wound about the retention wrap or vice versa.

18 A yarn as claimed in any preceding claim wherein the tenacity wrap is arranged to deform under impact into the retention wrap.

19 A yarn as claimed in any preceding claim wherein the tenacity wrap is formed from Keviar TM or Dyneema TM or Vecteran TM A yarn as claimed in any preceding claim wherein the textured wrap is arranged to facilitate tacticity in order to achieve rub retention when moved against other parts of the textured wrap to limited fraying.

21 A yarn as claimed in any preceding claim wherein the textured wrap allows retention of a dye.

22 A yarn as claimed in any preceding claim wherein the textured wrap is formed by air jet texturisation or a false twist texturing.

23 A yarn as claimed in any preceding claim wherein the textured wrap incorporates an anti-microbial agent.

24 A yarn as claimed in claim 23 wherein the anti-microbial agent is silver.

A yarn as claimed in any preceding claim wherein the textured wrap incorporates rubber elements.

26 A yarn as claimed in any preceding claim wherein the textured wrap is formed from a high tenacity polyester, high tenacity polypropylene or high tenacity nylon.

27 A yarn substantially seen as before described with reference to the accompanying drawings.

28 A protective garment comprising a knit of yarn as claimed in any preceding claim.