GB2414960A

GB2414960A - Heat retaining fabric

Info

Publication number: GB2414960A
Application number: GB0412694A
Authority: GB
Inventors: Timothy Austen Saltmarsh
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-08
Filing date: 2004-06-08
Publication date: 2005-12-14
Also published as: GB0412694D0

Abstract

A protective, heat-retaining fabric comprises at least a high durability layer 1, typically a nylon or polyester sheet; a heat-reflecting layer 2, typically a metallised thermoplastic sheet or film; and an insulating comfort layer 3, preferably a woven layer such as a fleece, all laminated or bonded to each other. The fabric may incorporate fixings 8 for carrying or for securing to a stretcher or carrying frame. The fabric may be made into a protective garment or body bag.

Description

24 4960 - 1

HEAT RETAINING FABRIC

This invention relates to a protective multi-layer fabric and to blankets and other articles made from or incorporating such multi-layer fabric.

In a first aid or emergency situation, there is often a lo requirement to protect a casualty from the effects of exposure or shock, or to restore body heat. Conventional woven fabrics may not be sufficiently wind- or waterproof.

Metallised films or sheets, the so-called "space blankets", reflect body heat back to the casualty. They are lightweight and can provide high windand water-resistance but may not have sufficient tear strength or abrasion resistance.

The present invention addresses the balance and provides a combination of these characteristics in a protective heat-retaining fabric.

According to one aspect of the present invention there is provided a multi-layer fabric including at least: (a) a high durability layer) (b) a heat-reflecting layer) and (c) an insulating comfort layer, wherein the three layers are laminated or bonded to each other.

In particular, there is provided a multi-layer fabric including at least: (a) a high durability layer) (b) a heat-reflecting layer) and (c) an insulating comfort layer, 2 - wherein the properties of the three layers are selected to balance a combination of characteristics of the fabric according to predetermined requirements.

"Fabric" comprises any flexible material that can be worn by or draped or wrapped around a person. A fabric may include woven or non-woven textiles; sheet or film material and the like; and any combination. The material of construction may be natural, for example wool; synthetic, lo for example polyamide, polyester or polypropylene; inorganic, for example glass fibre; and any combination. As discussed below, the different layers are normally made of different materials.

is Fabrics are characterized by a combination of parameters. Of particular relevance are: (a) water resistance (b) insulation (c) abrasion resistance (d) tear strength (e) wind resistance (f) moisture vapour transmission.

Definition and measurement of these and other characteristics are set out in detail in the various parts of British Standard BS 3424.

The present invention relates to a fabric wherein the overall characteristics may be selected according to the particular end use application. Particularly advantageous fabrics may be characterized by values substantially in the following ranges: (a) water resistance 5 m Hydrostatic Head (b) insulation 1 - 8 tog (c) abrasion resistance 1,000 - 10,000 Rubs (d) tear strength 100 - 300 Kg The high durability layer may conveniently comprise an extruded or calendered thermoplastic sheet, such as polyester or polyamide. Alternatively the high durability layer may comprise a woven or non-woven sheet or mat of inorganic fibres such as glass fibres, a synthetic material such as nylon or an organic material such as cotton or wool.

The high durability layer has abrasion resistance substantially in the range 25 - 40,000 rubs. Preferably the abrasion resistance is at least 3, 000 rubs or thereabouts lo and the tear strength is at least 200 Kg or thereabouts.

Suitable materials include polyamide or polyester sheet. If greater breathability is required the high durability layer may be woven from threads or fibres, such as 1000 denier polyester or 500 denier polyamide. The potential reduction in wind resistance resulting from use of a woven material may be counterbalanced by the barrier of the heat-reflecting layer.

The heat-reflecting layer preferably consists of or includes a flexible metal film adhering to a substrate. The metal film may be applied to a surface of the high durability layer. Preferably, however, the heatreflecting layer is distinct from the high durability layer.

The metal film may be applied to a polymeric, for example thermoplastic, film or sheet by conventional means, such as sputtering, vacuum evaporation or electro deposition. Alternatively the heat-reflecting layer may incorporate a mat or weave of metal-coated threads or fibres. Depending on the application, it may be possible for the heat-reflecting layer to consist solely of flexible metal foil, thereby obviating the necessity for a substrate.

Metallised fabrics utilise an aluminium coating, typically 5-15 um thick. Alternatively, precious metals such as gold or silver may be applied to a substrate. The minimum thickness is determined by the necessity of maintaining the - 4 integrity or continuity of the metal film. The maximum thickness is selected according to the desired properties of the metallised fabric. An advantage of the composite fabric of the present invention is that it may be possible to reduce the thickness of the metal film for particular applications. For metallised films or sheets the thickness of the metal film is conveniently in the range 10 - 30 Am and particularly substantially in the range 7-12 um.

When the heat-reflecting layer incorporates a mat or weave of metalcoated threads or fibres, the threads or fibres may be natural, synthetic or inorganic, conveniently 300 - 1000 denier. For synthetic fibres the metal film may be applied onto the fibre during extrusion. Other methods of metallisation may be employed as appropriate. The metal coating is conveniently 5 - 10 um thick.

It is readily apparent that there is no defined cut-off point or boundary for any of the parameters, characteristics or numerical ranges discussed herein. As indicated above the properties of the layers are selected to balance a combination of characteristics of the fabric according to predetermined requirements. All numerical values are therefore approximate and no particular precision of measurement is implied.

The insulating comfort layer is preferably woven. A particular preference is a fleece of variable weight, chosen for additional comfort and thermal protection.

Relative to each other, the high durability layer and the insulating comfort, for example woven, layer form mutually-opposed outer surfaces of the overall fabric. In other words, the heat-reflecting layer is sandwiched between the other two layers. - 5

The layers are permanently laminated or otherwise bonded to each other. Bonding extends over a significant portion of the mutually overlapping surfaces and preferably over the whole of such surfaces. A convenient bonding method is hot melt adhesion, but other methods of bonding will be readily apparent, depending on the materials forming the respective layers.

All three layers may be laminated in a single lo operation, or two may be bonded together and the third applied subsequently. For example, if the high durability layer and the heat-reflecting layer each comprise thermoplastic sheets or films, these two layers may be bonded together by calendering, hot roll pressing or concurrent extrusion. The insulating comfort layer is then bonded to the composite structure by hot melt adhesion.

A fabric according to the invention may be used as or incorporated in a heat-retaining blanket to cover a patient or casualty. Alternatively a sleeping bag or the like may be formed from or incorporate a fabric according to the invention. Such a sleeping bag is fastened in conventional manner. Preferably the fabric is shaped to provide a hood, which may be integral with or detachable from the blanket or sleeping bag.

In the use the woven layer is presented to the patient or casualty and the high durability layer presents outwards.

Preferably the high durability layer is strong enough to support a person's weight so that the fabric can be used to lift or drag a patient or casualty if necessary. For this purpose carrying handles or lifting points can be associated with or affixed to the high durability layer.

In an emergency it may be necessary to lift or drag a casualty as described above, but in many situations a blanket roll around the casualty may not be stiff enough, - 6 especially if there is a possibility of spinal injury.

Normally a blanket as described is used in conjunction with a stretcher or carrying frame. The high durability layer may include fixing points for attachment to a stretcher or carrying frame.

The fabric may also be used, for example: (a) In a breakdown situation, where the occupants of a vehicle need to be kept warm, whilst waiting for rescue.

lo (b) In an emergency situation, where a hypothermic casualty needs to be protected from all elements whilst being warmed up, either on land or sea.

(c) As a warm up jacket or blanket for athletes, before or after an event (d) As a protective layer when riding motorbikes or when passively exposed to the elements (e) As a protective layer between the ground and a person when sitting or lying.

(f) As a protective layer around a sleeping bag to add additional protection when required.

(g) As protective coating in outdoor activities such hang gliding.

The invention will now be described further by way of example with reference to the accompanying drawings, in which: Figure 1 is an exploded diagram showing the order of the three layers of a fabric according to this invention; Figure 2 is a view of an emergency protective bag made from a fabric according to this invention) Figure 3A is a view of a zipped emergency protective bag made from a fabric according to this invention in an open or unfolded condition; and Figure 3B is a view of the same zipped emergency protective bag in a closed position. - 7

Fig. 1 shows high durability layer 1, typically a nylon or polyester sheet; heat-reflecting layer 2, typically a metallised thermoplastic sheet or films and insulating comfort layer 3, preferably a woven layer such as a fleece.

Whether the fabric is wrapped around a person or made up into a protective bag or garment, in use high durability layer 1 will be on the outside and insulating comfort layer 3 will lie against the user.

lo Fig. 2 shows a protective body bag, indicated generally at 4, comprising a fabric according to the invention made up into a bag or sack in conventional manner. As discussed above high durability layer 1 is the outside (visible) surface. The open mouth of the bag is fitted with any convenient closure means, indicated generally at 5. Fig. 2 shows a drawstring closure 6 but any convenient means may be employed, such as buttons, lacing, or hook-and-loop fasteners as sold under the Registered Trade Mark VELCRO.

Fig. 3 shows a fabric according to the invention adapted to form a protective body bag by zipping the edges together. Fig. 3A shows the zip unfastened and the fabric unfolded. In Fig. 3B the fabric is folded over and the edges zipped together to form a bag or sack enclosing a person (not shown).

As previously, high durability layer 1 is on the outside and insulating comfort layer 3 on the inside. A heavy duty zip fastener 7 surrounds the perimeter in known manner. A pair of tubular sockets 8 run longitudinally, in relation to the bag in its assembled condition. Tubular sockets 8 are integral with or securely affixed to the fabric or, at least, high durability layer 1. Sockets 8 are adapted to receive carrying poles, thereby enabling the assembled bag to be used as an emergency stretcher.

Conveniently, sockets 8 may also define the lines of fold when assembling the bag. l 8

Alternatively, sockets 8 may be replaced by carrying handles or loops when significant stiffness is not required, or by attachment fittings enabling the assembled bag to be secured to a stretcher or carrying frame. In all cases, it is necessary that the tear strength of the fabric, as determined by the high durability layer, or of any bonds to the high durability layer is sufficient to support a person's weight.

Claims

I J _ 9 _ CLAIMS

1. A multi-layer fabric including at least: (a) a high durability layer; (b) a heat-reflecting layer; and (c) an insulating comfort layer, wherein the three layers are laminated or bonded to each other.

2. A fabric as claimed in Claim 1 wherein the heat- reflecting layer consists of or includes a flexible metal film.

3. A fabric as claimed in Claims 1 or 2 wherein the insulating comfort layer and the high durability layer form mutually opposed outer surfaces.

4. A fabric as claimed in any one of the preceding claims wherein the insulating comfort layer is woven.

5. A fabric as claimed in Claim 4 wherein the woven layer is a fleece material. 2s

6. A fabric as claimed in any one of the preceding claims wherein the high durability layer has abrasion resistance substantially in the range 25 40,000 rubs.

7. A fabric as claimed in any one of the preceding claims wherein the abrasion resistance of the high durability layer is at least 3,000 rubs and the tear strength is at least 200 Kg.

8. A fabric as claimed in any one of the preceding claims wherein the high durability layer is or includes a polyester or a polyamide. -

9. A fabric as claimed in any one of the preceding claims wherein the heat-reflecting layer includes a flexible metal film of thickness substantially in the range 10-30,um.

10. A fabric as claimed in Claim 9 wherein the thickness of the metal film is substantially in the range 7-12 m.

11. A fabric as claimed in any one of the preceding claims wherein the heat-reflecting layer includes a metal film adhering to a substrate.

12. A fabric as claimed in Claim 11 wherein the metal film is applied to a polymeric film or sheet.

13. A fabric as claimed in Claim 11 wherein the heat reflecting layer incorporates a mat or weave of metal coated threads or fibres.

14. A fabric as claimed in any one of the preceding claims wherein the properties of the three layers are selected to balance a combination of characteristics of the fabric according to pre-determined requirements.

15. A fabric as claimed in Claim 14 wherein the respective characteristics are substantially in the following ranges: (a) water resistance 5 - 20 m Hydrostatic Head (b) insulation 1 - 8 tog (c) abrasion resistance 1,000 10,000 Rubs (d) tear strength 100 - 300 Kq.

16. A fabric as claimed in any one of the preceding claims wherein the three layers are laminated by hot melt adhesion. - 11

17. A heat-retaining blanket including a fabric as claimed in any one of the preceding claims.

s

18. A protective bag including a fabric as claimed in any one of Claims 1 to 16.

19. Protective clothing including a fabric as claimed in any one of Claims 1 to 16.

20. A multi-layer fabric as claimed in any one of the preceding claims incorporating fixings for carrying or for securing to a stretcher or carrying frame.

21. A multi-layer fabric substantially as described and with reference to the accompanying drawings.