WO2000053039A1

WO2000053039A1 - Protective garment and process for its production

Info

Publication number: WO2000053039A1
Application number: PCT/GB2000/000880
Authority: WO
Inventors: Brian Garner Bennett
Original assignee: Bennett Safetywear Limited
Priority date: 1999-03-10
Filing date: 2000-03-10
Publication date: 2000-09-14
Also published as: GB9905349D0; EP1158877A1; AU3175100A; US6591427B1

Abstract

A protective garment such as a glove is knitted from a yarn comprising a heat-resistant core and a core covering comprising a carbon based yarn. The knitted garment is treated (e.g. by heating) to at least partially decompose the carbon based yarn to form activated charcoal in order to provide increased protection against chemical and/or biological risks.

Description

DESCRIPTION

PROTECTIVE GARMENT AND PROCESS FOR ITS PRODUCTION

The present invention relates to protective garments and in particular, but

not exclusively, to protective gloves (including gauntlets, mitts, mittens and the

like) incorporating activated charcoal.

There is a need for protective gloves and other garments which incorporate

activated charcoal, for use by those who may be exposed to chemical or biological risks, for example fire fighters. Although there are several types of fabric available incorporating activated charcoal which are used for clothing, they are generally not suitable for manufacturing gloves since gloves can be expected to be flexed

repeatedly in use and the known fabrics provide little or no stretch. Moreover, the existing gloves can be time consuming to manufacture.

The known types of fabric incorporating activated charcoal comprise several

yarns, one or more of which is a yarn of activated carbon which, when knitted with the other yarns, forms an integral part of the fabric and provides a protective function against chemical, biological and other risks. Unfortunately, the use of

carbon yarn results in products that are dusty and weak, which is not acceptable for a glove which would be expected to be flexed continuously and repeatedly.

It is an object of the present invention to provide a process of manufacturing gloves containing activated charcoal which overcomes or alleviates the problems associated with the prior art. In accordance with a first aspect of the present invention, a process of

manufacturing a protective garment comprises knitting a garment from a yam

having a heat-resistant core and a core covering comprising a carbon based yarn

compound and treating the knitted garment to at least partially decompose the

carbon based yarn to form activated charcoal.

In accordance with a second aspect of the present invention, a protective

garment is made from a yarn having a heat-resistant core and a core covering

comprising a carbon based yarn which has been at least partially carbonised to form

activated charcoal.

It is believed that the activated charcoal formed on treating the garment is bound to the heat-resistant core, resulting in a fabric from which little or no

activated charcoal escapes. Moreover, the use of a heat-resistant core results in a

garment which shrinks much less than the prior art garments and at a more

predictable rate.

The carbon based yam may be decomposed partially or substantially completely to form activated charcoal.

Preferably, the treatment of the knitted garment to at least partially decompose the carbon based yarn comprises heating.

The yarn may comprise a core spun yarn and may comprise a steel, ceramic

or glass core. The covering may comprise viscose, either filament or spun, or lyocell. Preferably, the knitted garment is located on a former during the heating

stage to assist in reducing and/or controlling the degree of shrinkage and to assist in

retaining the shape of the garment during heating.

Once the garment has been produced then one or more coatings may

optionally be applied to its surface. For example, a curable plastisol such as PVC

or latex may be screenprinted onto the garment in a predetermined pattern, eg: a

matrix of dots. Alternatively or in addition, the garment may be dipped into the

curable plastisol and subsequently cured. The plastisol may, for example, contain

powdered activated carbon particles, thus increasing the chemical absorption characteristics of the glove and strengthening the glove considerably.

If desired, one or more further coatings may be applied. For example, a

further series of dots (eg: PNC dots) may be applied to the surface of the garment to increase abrasion resistance.

The present invention also includes a protective garment made in accordance with the first aspect of the invention.

By way of example only, a specific embodiment of the present invention

will now be described, with reference to the accompanying drawings in which :-

Fig. 1 is a flow diagram illustrating one method of producing gloves in accordance with the present invention;

Fig. 2 is the plan view of a former which may be used in the method of the present invention; Fig. 3 is a side view of the former illustrated in Fig. 2;

Fig. 4 is a plan view of a glove manufactured in accordance with the present

invention, to which a first coating has been applied; and

Fig. 5 is a plan view of the glove of Fig. 4, to which a second coating has

been applied.

Referring firstly to Fig. 1, at Step 10 a glove is knitted in a conventional manner on a standard glove knitting machine. However, the yarn which is used comprises a core spun yarn consisting of a heat-resistant core with a covering

comprising a carbon based yarn, i.e. a yarn comprising carbon in a chemically

bonded form. For example, the heat-resistant core may comprise metal (e.g. steel), ceramic or glass. The coating may, for example, comprise viscose, either filament or spun or lyocell. Such yams are already known and an example of these yams is a yam with a glass core and a viscose coating (possibly treated with a flame-

retardant treatment) spun on a DREF machine.

At Step 12 the knitted glove is then placed on a former 28, one example of which is illustrated in Figs. 2 and 3. The former corresponds generally to the shape of the glove and will vary in size and shape, depending upon the size and

shape of the glove to be produced. In general, however, the former will be planar,

as illustrated in Fig. 3 and will be of a heat-resistant material, preferably metal.

After the glove has been placed on the former, at Step 14 the former with

the glove positioned thereon is placed in an oven and is heated to a temperature at which carbonisation of the carbon based yarn coating of the core spun yarn takes

place. The application of heat may be sufficient to result in substantially complete

carbonisation of the carbon-containing coating or may, if desired, be adjusted in

order to produce partial carbonisation.

One option is to apply a high heat flux to the garment at step 14 in order to

carbonise the outer portions of the yarn but to retain the inner portions intact. This

is thought to increase the retention within the garment of the activated carbon

formed during heating.

By using known techniques such as plating or making pile fabric it is

possible to build a garment in one operation using advanced heat resistant fibres such as the aramids, PBI and PBO. By utilising a high heat flux with such

materials, a temperature profile can be created so that different parts of the fabric

would be at different temperatures, thus carbonising one part of the material but

leaving another part intact. The use of a high performance material such as those described facilitates this partial carbonisation, since it can be difficult to control the temperature accurately.

After being heated at the required temperature and for the appropriate length

of time, the former and glove are removed from the oven at Step 16. Normally the process will proceed to Step 18 (path A) where the glove is allowed to cool and at

Step 20 it is removed from the former. As an alternative, after the glove is

removed from the oven it is removed from the former at Step 20 before being allowed to cool substantially (path B).

Alternatively, after removing the former and glove from the oven at Step 16

or after cooling the glove at Step 18, the glove, still on the former, may have a

coating applied to it at Step 22 (paths C and D). For example, a curable plastisol

such as PVC may be screenprinted onto the glove by conventional techniques or

may be applied to a or may be applied by a conventional dipping process. The

plastisol may contain powdered activated carbon particles which would increase the

chemical absorption characteristics of the glove and would also strengthen the product significantly. For example the technique described in EP-A-0118618 (von

Blucher et al) may be used. The plastisol may be applied in a predetermined pattern, eg: in the form of a matrix of circular dots 30 on the surface of the glove

32, as illustrated in Fig. 4. Of course, other coatings may be applied instead.

If the coating is applied by dipping, it will normally form a larger continuous area of coating material.

Optionally, at Step 24, a further coating may be applied. In the example

given, and as illustrated in Fig. 5, the further coating is screenprinted in the form

of a matrix of circular dots 34 of PVC material, to increase abrasion resistance. In

the example given rows of dots 34 of the second coating are shown as being applied in between rows of dots 30 of the first coating. However, the number, shape and position of the dots can be varied as required.

As a variant, the first and/or second coatings could be applied some time after manufacture of the glove itself, in which case it would be necessary to place

the glove on a former prior to application of the coating, as illustrated

schematically at Step 26 (path E) before carrying out Step 22 and/or Step 24.

Further coatings could be applied, if desired.

The glove could be for use as a protective glove in its own right and/or as a

lining inside a different glove. For example, the glove may be used as a lining

inside a protective leather glove, which would be particularly suitable for use by

the fire services. An additional benefit of using a core spun yarn having a steel,

glass or ceramic core would be that the glove (or liner) would additionally be cut

resistant.

The invention is not restricted to the details of the foregoing embodiment. For example, although the specific embodiment is described in the context of gloves, the invention is equally applicable to other garments such as, but not

exclusively, gauntlets, mitts, mittens (with and without fingers, thumbs or cuffs), socks and underwear.

Claims

1. A process for manufacturing a protective garment, comprising knitting a

garment from a yarn having a heat-resistant core and a core covering comprising a

carbon based yarn compound and treating the knitted garment to at least partially

decompose the carbon based yarn to form activated charcoal.

2. A process as claimed in claim 1, wherein the carbon based yarn is

decomposed partially to form activated charcoal.

3. A process as claimed in claim 1 , wherein the carbon based yarn is

decomposed substantially completely to form activated charcoal.

4. A process as claimed in any of claims 1 to 3, wherein the treatment of

the knitted garment to at least partially decompose the carbon based yarn comprises

heating.

5. A process as claimed in any of claims 1 to 4, wherein the knitted garment is located on a former during the treatment.

6. A process as claimed in claim 5, wherein the garment is allowed to cool before being removed from the former.

7. A process as claimed in any of claims 1 to 6, wherein the yam from which the garment is knitted comprises a core spun yarn.

8. A process as claimed in claim 7, wherein the core is selected from a group comprising steel, ceramic and glass.

9. A process as claimed in any of claims 1 to 8, wherein the core covering comprises viscose.

10. A process as claimed in claim 9, wherein the core covering comprises

filament viscose.

11. A process as claimed in claim 9, wherein the core covering comprises

spun viscose.

12. A process as claimed in any of claims 1 to 8, wherein the core covering

comprises lyocell.

13. A process as claimed in any of the preceding claims, further

comprising applying one or more coatings to the surface of the garment.

14. A process as claimed in claim 13, wherein the garment is located on a

former during application of the or each coating.

15. A process as claimed in claim 13 or claim 14, wherein one or more coatings comprises a curable plastisol.

16. A process as claimed in claim 15, wherein the curable plastisol is

selected from the group comprising polyvinyl chloride (PVC) and latex.

17. A process as claimed in any of claims 13 to 16, wherein one or more coatings contains activated carbon.

18. A process as claimed in any of claims 13 to 17, comprising applying a coating to the garment by means of dipping.

19. A process as claimed in any of claims 13 to 18, wherein a coating is

applied to the garment in a plurality of discrete, separate areas.

20. A process as claimed in claim 19, wherein the coating comprises a

plurality of dots of coating material.

21. A process as claimed in claim 20, wherein the dots are printed onto the

garment.

22. A protective garment knitted from a yarn comprising a heat-resistant

core and a core covering comprising a carbon based yarn which has been at least

partially carbonised to form activated charcoal.

23. A protective garment as claimed in claim 22, wherein the carbon based

yam is decomposed partially to form activated charcoal.

24. A protective garment as claimed in claim 22, wherein the carbon based yarn is decomposed substantially completely to form activated charcoal.

25. A protective garment as claimed in any of claims 22 to 24, wherein the yarn from which the garment is knitted comprises a core spun yarn.

26. A protective garment as claimed in claim 25, wherein the core is selected from a group comprising steel, ceramic and glass.

27. A protective garment as claimed in any of the preceding claims, wherein the core covering comprises viscose.

28. A protective garment as claimed in claim 27, wherein the core covering comprises filament viscose.

29. A protective garment as claimed in claim 27, wherein the cover covering comprises spun viscose.

30. A protective garment as claimed in claim 27, wherein the cove

covering comprise /lyocell.

31. A protective garment as claimed in any of claims 22 to 30, further

comprises one or more coatings applied to the surface of the garment.

32. A protective garment as claimed in claim 31, wherein one or more

coatings comprises a cured plastisol.

33. A protective garment as claimed in claim 32, wherein the cured

plastisol is selected from the group comprising polyvinyl chloride (PVC) and latex.

34. A protective garment as claimed in any of claims 31 to 33, wherein one

or more coatings contains activated carbon.

35. A protective garment as claimed in any of claims 31 to 34, comprising a coating applied to the garment in a plurality of discrete, separate areas.

36. A protective garment as claimed in claim 35, wherein the coating comprising a plurality of dots of coating material.

37. A protective garment as claimed in claim 36, wherein the dots are

printed onto the garment.