GB2471021A

GB2471021A - Elastic netting

Info

Publication number: GB2471021A
Application number: GB1009792A
Authority: GB
Inventors: John Usher
Original assignee: Scobie & Junor
Current assignee: Scobie & Junor
Priority date: 2009-06-12
Filing date: 2010-06-11
Publication date: 2010-12-15
Also published as: GB0910153D0; GB201009792D0

Abstract

An elastic net for wrapping a food product, such as a joint of meat, poultry, fish or dairy products, or for use as stockinette for holding dressings or bandages in place on a patient, comprises a plurality of long chain warp yarns (12) knitted with an elastic weft yarn (16). The weft yarn comprises a synthetic elastic material such as synthetic polyisoprene or silicone and has a rectilinear cross-section. The use of a synthetic elastic yarn may eliminate allergy problems. The rectilinear cross-section helps prevent the yarn from rolling in use and so improves the stable positioning of the net. The weft yarn may be formed by moulding, slitting and/or cutting and is preferably of square cross-section. The netting will preferably withstand a temperature of around 210 degrees centigrade.

Description

ELASTICATED NET

The present invention relates to an elasticated net particularly, but not exclusively, for wrapping food products, for example meat, poultry, fish, cheese and dairy products. The net can also be used in other applications which require an elasticated net, such as elasticated stockinettes used to hold medical or surgical dressings or bandages in place on a patient.

Elasticated nets are used for wrapping meat products. A commonly used net product has inelastic warp yarns which are knitted with an elasticated weft yarn of latex rubber which is generally spirally wound in the net and which retains the meat in its rolled or wrapped shape. Food grade latex rubber has a yellow colour, and is not visually attractive. Moreover latex rubber is naturally tacky and does not lend itself well to loading onto tubes for use with meat wrapping machinery. To overcome these problems the latex rubber weft yarn is generally wrapped with an inelastic coloured yarn, for example red or white polyester yarn, wound around the latex rubber weft yarn. If the warp yarns are of uncoloured material then the use of the elasticated net on a meat product can give the meat product the appearance as if it were skilfully wrapped by tying only string around the meat, so that the wrapped meat appears attractive to the consumer.

However the use of latex rubber can lead to allergy problems, not only in products used with foodstuffs, but also in medical products, such as elasticated tubular bandages. Moreover latex rubber yarns have a generally circular cross-section and therefore have a tendency to roll across the surface of a foodstuff, resulting in an uneven distribution of the weft yarns near the ends of the elasticated net, where the weft yarns are not evenly restrained by the warp yarns.

It is an object of the present invention to provide an improved elasticated net which obviates or mitigates at least one of the aforesaid disadvantages.

According to a first aspect of the present invention there is provided an elasticated net comprising a plurality of long chain warp yarns knitted with at least one elasticated weft yarn, wherein the elasticated weft yarn comprises a synthetic elastic material having a substantially rectilinear cross-section.

The synthetic elastic material may be uncovered. The synthetic elastic material is less tacky than latex rubber, so wrapping with another yarn is not so essential to reduce friction when loaded onto tubes for use with meat wrapping machinery. However the synthetic elastic material may be covered, or at least partially covered, if required, either for aesthetic purposes, or to reduce the friction with the tubes even further, for example by wrapping with yarn or coating with a suitable powder or similar.

The synthetic elastic material may be silicone, in particular silicone rubber which can be formed into yarn through extrusion or a similar process.

The synthetic elastic material may comprise polyisoprene, in particular synthetic polyisoprene yarn, which may be formed by cutting or splitting and has a rectilinear cross section.

In one embodiment the weft yarn has a substantially square cross-section.

Preferably the warp yarns and weft yarn are stable up to a temperature of about 210°C.

The warp yarns may be of polyester. They may also be of cotton, rayon or any other suitable food contact yarn. The warp yarns may be multifilament or monofilament.

Preferably the warp yarn is substantially inelastic.

In a preferred embodiment the net is a food wrapping net. Suitable food includes, but is not limited to, meat, poultry, fish and cheese.

In another preferred embodiment the net is a surgical elasticated stockinette for use to hold dressings or bandages in place on a patient.

According to a second aspect of the present invention there is provided a method of manufacturing continuous netting, said method comprising the steps of providing a plurality of warp yarns, knitting the warp yarns to form long chain warp yarns, feeding an elasticated weft yarn comprising an synthetic elastic material having a substantially rectilinear cross-section, and knitting the warp yarns with the weft yarn to form a continuous netting.

The synthetic elastic material may be uncovered, covered or partially covered.

The synthetic elastic material may be silicone.

The synthetic elastic material may comprise polyisoprene, in particular synthetic polyisoprene yarn.

In a preferred embodiment the weft yarn has a substantially square cross-section.

Preferably the warp yarns and weft yarn are stable up to a temperature of about 21000.

Preferably the warp yarn is substantially inelastic.

According to a preferred embodiment the netting is for wrapping a food product. The netting may be subsequently stored, for example on a reel, and placed around a food product, such that the food product is held in compression by the elasticated weft yarn. The netting may be stretched radially by a tube through which the food product is passed. The netting may be fed around the food product, and may be cut to length.

According to another preferred embodiment the netting is subsequently cut into discrete lengths to form elasticated stockinettes. An elasticated stockinette is subsequently placed around a dressing or bandage on a limb or other part of a body, such that the dressing or bandage is held against the part of the body by the elasticated weft yarn.

The invention will be described, by way of non-limiting example, with reference to the following drawings, in which: Fig. 1 shows a net according to the invention being part of continuous netting suitable for wrapping a meat product; Fig. 2 is a sectional view through a meat product wrapped by the net of Fig.1;and Fig. 3 is a partial view to an enlarged scale of a warp yarn of the net of Fig. 1, showing how the weft yarn is held in the knitted chain.

Referring to Figs. 1 and 3 there is shown a net 10 comprising a plurality of warp yarns 12 which are knitted to form long chains 14. At every fourth stitch along the chain a weft yarn 16 is held within the knitted loop. The weft yarn 16 is spirally wound around the warp yarns 12, which are arranged around a cylinder, so that the net forms a tubular sock. Typically the net is formed as continuous netting by a suitable circular knitting process, such as that described in US 5,207,279. The finished netting is typically stored by wrapping on a spool, and is placed around a meat product 20 by feeding the netting from the spool, stretching it around a meat product by means of a tube, releasing the netting and cutting to length, thereby forming a net which holds the meat product. Although the invention is described with reference to a meat product, it is to be understood that the invention can be used with any food product, such as meat, poultry, fish or cheese.

The weft yarn is elasticated so that the weft yarn remains under tension when the netting is released around the meat product, to hold the meat product firmly. The weft yarn is an uncovered synthetic elastic material. It has been found that synthetic polyisoprene and silicone rubber are of particular benefit in exhibiting the required elastic properties while being able to withstand temperatures of up to about 210°C or more during cooking and of up to -20°C or less during frozen storage of the meat product.

synthetic polyisoprene and silicone rubber can both be supplied in a wide variety of colours, enabling the selection of an appropriate colour of weft thread for particular uses. For example netting could be supplied in different colours for different sizes of meat product, or for different types of meat product.

Silicone rubber may be readily formed by extrusion to any required shape, enabling the selection of an appropriate cross-sectional shape of weft yarn for particular uses, for example rectangular or square cross-section.

Synthetic polyisoprene yarn can be formed by cutting or splitting to have an appropriate rectilinear cross-sectional shape.

In Fig. 3 the weft thread 16 has a rectilinear cross-section which fits closely against the meat product 20 and has a reduced tendency to roll relative to the meat product. The warp threads are omitted for clarity. This results in a more even appearance of the weft yarn on the meat product, since the weft yarn will tend to stay where it is placed on the meat, even when the ends of the netting are cut.

The surface of synthetic elastic yarn is relatively smooth, and does not exhibit the tackiness of latex rubber yarn, so that it can be knitted using conventional circular warp thread knitting machines and fed onto foodstuff products using feeding tubes without the need to wrap or otherwise treat the surface of the elasticated weft yarn to the same extent as with latex rubber. This reduces the cost of the elasticated yarn, since it is often not necessary for the elasticated rubber yarn to undergo the wrapping process, and there is a saving on material, conventionally polyester yarn, used to wrap the elasticated rubber yarn. Even if some wrapping or covering is provided, for example to further reduce friction, or for aesthetic purposes, less material is required.

The diameter of the net and the number of warp yarns can be varied, according to the requirements of the meat product to be wrapped.

Typically there may be 16, 24, 32 or 48 warp yarns. The diameter is dependent on the tension of the weft yarn when it is introduced to the knitted warp yarns. The higher the tension, the smaller is the resulting diameter. Because the surface of the synthetic elastic yarn is consistent, it is possible to achieve a consistent tension through the known friction devices used to introduce weft yarn under tension into circular knitting machines, so that the diameter of the resulting net is also consistent.

The weft yarn 16 may instead be provided at every third stitch, or any other spacing as appropriate.

The use of synthetic elastic yarn offers the further advantage of avoiding the risk of allergic reactions by users of the net and consumers of the meat product to latex rubber, which has been used hitherto in elasticated meat netting products. There has been a rise in incidence of atopic allergic disease in the past 30 years, which is thought to be a major factor in the cause of Natural Rubber Latex (NRL) Allergy.

It will be understood that various modifications may be made to the nets of the present invention without departing from the scope of the invention.

For example, the long chain warp yarn and cross chain weft yarns may be made of any suitable material which can be knitted into a net for use under any foreseeable cooking conditions. Examples of such materials are polyester, cotton, rayon, KevlarTM and MylarTM. Although the invention has been described with silicone rubber or synthetic polyisoprene as the synthetic elastic material, any other suitable synthetic elastic material which meets food safety legislation and has a sufficient temperature resistance for the particular application may be used. An elastane may be used if the temperature resistance of the elastane is suitable for the intended application. The weft yarn may be formed by extrusion, moulding, splitting or cutting, or a combination of these. The net of the invention may be manufactured by any suitable process and is not limited to a net formed by a circular warp knitting machine.

Although the invention has been described above in connection with nets for use with meat products, it is to be understood that the nets could be used for any suitable purpose. In particular the anti-allergic properties of the silicone rubber used in the weft yarns make the nets suitable for use as tubular elasticated bandages. Clearly the spacing of the warp and weft yarns may be much less for a net used as a bandage than for a net used as a meat net. It will be apparent that the nets of the invention can be manufactured as close knit or loose knit products, as appropriate.

Claims

CLAIMS1. An elasticated net, said net comprising a plurality of long chain warp yarns knitted with at least one elasticated weft yarn, wherein the elasticated weft yarn comprises a synthetic elastic material having a substantially rectilinear cross-section.
2. An elasticated net according to claim 1, wherein the synthetic elastic material is uncovered.
3. An elasticated net according to claim 1, wherein the synthetic elastic material is wrapped.
4. An elasticated net according to any preceding claim, wherein the synthetic elastic material is silicone.
5. An elasticated net according to any of claims 1 to 3, wherein the synthetic elastic material comprises polyisoprene.
6. An elasticated net according to any preceding claim, wherein the weft yarn has a substantially square cross-section.
7. An elasticated net according to any preceding claim, wherein the warp yarns are substantially inelastic.
8. An elasticated net according to any preceding claim, wherein the net is a food product wrapping net.
9. An elasticated net according to claim 8, wherein the warp yarns and weft yarn are stable up to a temperature of about 210°C.
10. An elasticated net according to claim 8 or 9, wherein the warp yarns are of polyester.
11. An elasticated net according to any of claims 1 to 7, wherein the net is an elasticated surgical stockinette.
12. A method of manufacturing continuous netting, said method comprising the steps of providing a plurality of warp yarns, knitting the warp yarns to form long chain warp yarns, feeding an elasticated weft yarn comprising a synthetic elastic material having a substantially rectilinear cross-section., and knitting the warp yarns with the weft yarn to form a continuous netting.
13. A method according to 12, wherein the synthetic elastic material is silicone.
14. A method according to claim 12,wherein the synthetic elastic material comprises polyisoprene.
15. A method according to any of claims 12 to 14, wherein the weft yarn has a substantially square cross-section.
16. A method according to any of claims 12 to 15, wherein the warp yarns and weft yarn are stable up to a temperature of about 21000.
17. A method according to any of claims 12 to 16, wherein the warp yarns are of polyester.
18. A method according to any of claims 12 to 17, wherein the warp yarns are substantially inelastic.
19. A method according to any of claims 12 to 18, wherein the netting is for wrapping a food product.
20. A method according to claim 19, wherein the netting is subsequently stored and placed around a food product, such that the food product is held in compression by the elasticated weft yarn.
21. A method according to any of claims 12 to 18, wherein the netting is subsequently cut into discrete lengths to form elasticated surgical stockinettes.
22. A method according to claim 21, wherein an elasticated surgical stockinette is subsequently placed around a surgical dressing on a part of a body, such that the surgical dressing is held in place by the elasticated weft yarn.
23. A food product comprising a portion of meat having an elasticated net according to any of claims 1 to 10 placed around the portion of meat, such that the portion of meat is held in compression by the elasticated weft yarn.
24. An elasticated net as described herein with reference to the accompanying drawings.