WO2002045801A2

WO2002045801A2 - Protective garments

Info

Publication number: WO2002045801A2
Application number: PCT/GB2001/005323
Authority: WO
Inventors: Christoper Giness; Brian Sagar
Original assignee: Reflec Plc
Priority date: 2000-12-07
Filing date: 2001-12-03
Publication date: 2002-06-13
Also published as: WO2002045801A3; AU2002220864A1

Abstract

A protective garment, having conspicuity provision, with breathability which is not compromised by its conspicuity provision.

Description

Protective Garments

This invention relates to protective garments, particularly, but not exclusively to fire protection garments such as may be worn by fire fighters.

Fire protection garments primarily need to afford the wearers protection against heat and flame. Many fires manifest visibility obscuring smoke, and another desirable in a fire fighting garment is visibility, especially under obscuring conditions.

To render fire protection garments more visible under obscuring conditions, retroreflective tapes are attached to the garments, which also display yellow fluorescence. Of course, such tapes are also attached to other protective garments, especially waterproofs such as may be used by police and other outdoor workers. While the tapes certainly provide conspicuity, even more conspicuity would be advantageous. The tapes clearly cannot cover the entire garment without making it unacceptably stiff and heavy. As tapes, they appear as linear features, rather than as being of human form, and may not be picked out in obscuring conditions, especially if there is no movement.

The present invention provides a protective garment which can have more conspicuity than can be provided by tapes, yet without the disadvantages of all-over taping.

The invention comprises a protective garment having conspicuity provision with breathability.

In a fire protection garment, it is often found that wearers have experienced serious burns or scalds under the taped regions when exposed to heat or flame. This is now ascribed to the fact that the tapes compromise the breathability of the garment, so that moisture cannot transfer across the garment in the region of the tape, and the fire fighter is scalded by his own perspiration. Breathability is important also in outdoor clothing.

One method of providing large area conspicuity without compromising breathability is to apply an overall conspicuity provision in discontinuous fashion.

In particular, the conspicuity provision may comprise printing on the garment, applied over a substantial area thereof, but in discontinuous fashion.

Another method is to apply a conspicuity affording ink by solid printing in such fashion as itself to be breathable and not compromise breathability of the substrate.

The conspicuity provision may, of course, still comprise tapes or other appliques provided that they are themselves breathable and are applied to the garment in such manner as not to compromise breathability of the garment.

An applique may be attached adhesively if the adhesive is moisture- permeable or is applied discontinuously, as in discrete dots.

For fire fighting garments, the conspicuity may be applied by printing of a fire retardant ink applied over substantial area of the garment in a discontinuous fashion.

The ink may be retroreflective, as by comprising semi-silvered microbeads, or unsilvered microbeads over reflective particles such as aluminium or mica flakes.

The printing may, however, be solid, but with the ink subject during printing to a suction force towards the back face of the fabric. This is found to cause the retroreflective microbeads to be drawn into the spaces between warp and weft crowns of a woven fabric, or between stitch loops of a knitted fabric, which additionally results in a higher bead density and a better uniformity of retroreflection over a wide range of angles of incidence. More importantly, for present purposes, however, it results un unimpaired or substantially unimpaired breathability through ink and fabric.

The printing may have a pattern of small printed lands surrounded by unprinted regions, or the reverse.

Especially for fire protective garments, but also of more general advantage, the ink may be capable of withstanding a challenge at mean heat flux level of 80kW/m² for 8 seconds. If retroreflective, the ink may be arranged to withstand that challenge while retaining useful retroreflectivity, preferably at least 40% of its original retroreflectivity .

A fire protection garment may comprise a knitted or woven fabric of a high temperature polyamide, such as Nomex®, or any other fabric that has been treated with a fire retardant such as Proban®.

The invention, in another aspect, provides for further improved conspicuity in obscuring conditions.

The invention, in that other aspect comprises a method for facilitating visibility of objects in obscuring conditions comprising applying to the objects a retroreflective facility and providing infra red illumination for detection of retroreflected infra red radiation by an infra red imaging device.

The infra red imaging device may be a CCD camera; an optical system may include an infra red filter. The infra red illumination may be provided close to the optical axis of the infra red imaging device.

Embodiments of garments and a method according to the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a back view of a firefighter's protective jacket;

Figure 2 is a like view of a prior art jacket;

Figure 3 is a first pattern of discontinuous printing;

Figure 4 is a second pattern of discontinuous printing; and

Figure 5 is a view of an emergency worker in need of rescue and an infra red camera being used to search for same.

Figure 1 illustrates a fire protection garment, in the form of a jacket 11, comprising a fire resistant fabric such as Nomex®, or some other, not inherently fire resistant fabric, treated for example with a fire retardant such as Proban®, printed or coated with a fire retardant, retroreflective ink. The ink is applied over substantial areas - as illustrated, over the whole area of the garment 11 - but in a discontinuous fashion. Inks have been devised expressly for the purpose of reducing flammability of fabrics used as backdrops in virtual film and video studios for the purpose of chromakeying. Such studios are usually replete with high-intensity lighting, and is it desired to reduce fire hazard as much as possible, The backdrop fabric is not, itself, necessarily fireproof.

It has now been found, however, that the application of this fire retardant ink to fire resistant garments such as are worn by fire fighters has considerable advantage over prior art visibility provisions, such as are illustrated in Figure 2, which is a back view of a jacket 12 like that of Figure 1, but not coated or printed all over with fire retardant retroreflective ink. Rather, the jacket 12 has PVC tape 13 coated with retroreflective microbeads.

In flame tests, the PVC tape melted and retained no retroreflectivity. The jacket 11, however, withstood a challenge by two burner arrays with a mean heat flux level of 80kW/m² for 8 seconds, without catching fire. The ink showed 43% retroreflectivity retention after this challenge, and was highly visible in low to medium levels of smoke.

However, the major disadvantage of the use of tapes, as in jacket 12, is that, under such conditions, the wearer would suffer sever burns or scalds directly beneath the taped areas. This is now thought to be due to the tape 13 acting as a barrier to the transfer of moisture across the garment/tape combination, so that a firefighter can be scalded by his own perspiration.

By printing the garment 11 overall, in a discontinuous fashion, not only does the garment have better conspicuity and retain such even in adverse conditions, but the incidence of such sub-tape burns or scalds is eliminated.

Patterns of printing suitable for fire protection garments are illustrated in Figures 3 and 4. In Figure 3, the ink is applied as minute dots 31 surrounded by non- inked area 32. In Figure 4, the ink is applied overall except in dots 41. "Patterns" may, of course, be random.

A suitable coverage is about 30% of printed areas inked, It appears to be important to arrange that, with respect to any inked area, there is an adjacent non-inked area ensuring that a pathway exists through the fabric from anywhere under an inked area so that the ink does not significantly impede transpiration even from beneath a central region of the inked area. It can readily be arranged, for example, that no point beneath an inked area is more than one or two thicknesses of the material distant from a point under an inked area.

Discontinuous printing can be avoided if solid colour printing is effected over a suction arrangement, which results in a very high level of solids - microbeads and pigment, the latter for daytime conspicuity - which in turn gives a high level of retroreflectivity over a wide range of angles of incident light. The suction, applied from behind the substrate during printing, also results in the substrate and ink coating being permeable, so breathability is unimpaired or substantially so. Clearly, overall solid printing, using the suction technique, is even better than discontinuous printing from the point of view of conspicuity.

The retroreflectivity extends down to the infra-red region of the spectrum.

While the invention has been particularly described with reference to fire protection garments, it is quite within the scope of the invention to apply conspicuity in similar fashion to other garments such as outdoor clothing, especially for police and other emergency services, even where fire protection is not of paramount importance. All-over conspicuity, especially night time conspicuity, is better than applied tapes of retroreflective material, as the outline of the human figure is more readily picked out and distinguished from background features than linear tapes. Breathability is of considerable importance in outdoor clothing, which must keep the wearer warm but dry, which means that moisture from perspiration must be allowed to escape. Tapes, however, are not ruled out. It may, for instance, be required to render conspicuous garments which have already been made, and for which overall printing is out of the question. Tapes which are themselves of breathable material may be printed with discontinuous printing of retroreflective or otherwise conspicuous ink and applied to the garment in a manner which does not compromise the breathability of the garment, as, for example, by adhesive which is itself applied discontinuously. This is possible even with fire protection garments, where another problem might be the melting of a thermoplastic adhesive, which might, despite discontinuous printing, tend to spread out on melting, a solution to which is to use an adhesive which cross links to become thermoset on heating above a certain temperature.

In fire situations, toxicity is important. PVC tapes will give off quantities of chlorine and toxic chlorine compounds on combustion. Inks, however, can be water based, and can in any event be selected to have low toxicity on heating. Even with overall printing, however, the total quantity of ink will be substantially less than the quantity of PVC in conspicuity tapes.

Figure 5 of the drawing shows an emergency worker 51, overcome, perhaps, by smoke, with a jacket 52 having conspicuity-providing retroreflective tape 53 in a readily recognisable pattern.

The present of smoke would ordinarily severely hamper rescue work, even with the retroreflective facility afforded by the tape 53.

It is found, however, that infra red and radiation can also be retroreflected by, for example, glass microbeads, hemispherically coated with a reflective metal such as aluminium or plain microbeads backed by reflective metallic or mica flake which can be coated on to the tape 53. Using an infra red camera 54 with an infra red source 55 close to the optical axis thereof - eg. disposed in a ring around the lens thereof - can, however, show up the retroreflective material, if the wave length of the infra red light used is appropriate.

Instead of tapes, printing or coating the jacket fabric with a retroreflective ink or coating can provide a much greater retroreflective area, and it can be arranged that the printing or coating can "breath", avoiding scalding problems associated with impervious retroreflective tapes.

Equipment such as breathing sets, as well as signage, may be rendered conspicuous in the same way as garments, for emergency services. Nor is smoke the only obscuring condition - cloud, for example, in mountain rescue, can be effectively penetrated by infra red. Airborne dust, also, as in coal or rock falls in mining, caving and so forth. Signage in buildings, transportation vehicle, as well as road and street signage, can also be treated in this way. Vehicles could be equipped with IR transmitters and imaging devices assisting navigation in fog.

Claims

1. A protective garment, having conspicuity provision, with breathability which is not compromised by its conspicuity provision.

2. A garment according to claim 1, comprising a fire protection garment.

3. A garment according to claim 1 or claim 2, in which the conspicuity provision comprises printing on the garment which

• comprises a fire retardant ink, and

• is applied over a substantial area of the garment in discontinuous fashion.

4. A garment according to claim 1 or claim 2, in which the conspicuity provision comprises printing on the garment which

• comprises a fire retardant ink which is applied solidly over a substantial area of the garment in such a fashion as to be breathable and not to compromise breathability of the garment.

5. A garment according to claim 4, in which the ink during application has been subjected to a suction force towards the back face of the fabric of the garment.

6. A garment according to any one of claims 1 to 3, in which the conspicuity provision comprises an applique on the garment which

• comprises a fire-retardant coating, and • is breathable and is attached to the garment in such manner as not to compromise breathability of the garment.

7. A garment according to claim 6, in which the applique is adhesively attached to the garment.

8. A garment according to claim 7 in which the applique is attached to the garment by an adhesive applied discontinuously.

9. A garment according to claim 7 or claim 8, in which the adhesive is a thermoplastic adhesive said at a given temperature cross-links to become a thermostat adhesive.

10. A garment according to claim 9, in which the thermoplastic adhesive melts at about 260°c.

11. A garment according to any one of claims 1 to 10, in which conspicuity provision is affected by a printed or otherwise attached coating with a pattern of small coated lands surrounded by uncoated regions or the reverse.

12. A garment according to any one of claims 1 to 11, in which conspicuity provision is afforded by a solid print of breathable ink.

13. A garment according to any one of claims 1 to 12, in which the conspicuity provision comprises a coating capable of withstanding a challenge POKW/m² for 8 seconds and retain useful conspicuity.

14. A garment according to claim 13, in which the conspicuity is affected by retro reflectivity of which at least 40% is retained after the challenge. - i l ¬

ls. A garment according to any one of claims 1 to 14, comprising a fire resistant fabric.

16. A garment according to claim 15, in which the fire resistant fabric is woven or knitted from a high temperature polyamides.

17. A garment according to claim 15 and claim 16, in which the garment is woven or knitted from a fabric which has been treated with a fire retardant finish.

18. A garment according to any one of claims 1 to 12, in which conspicuity is provided by the retro reflectivity.

19. A garment according to any one of claim 17, in which retro reflectivity is afforded by retro reflectivity microbeads.

20. A garment according to claim 19, in which the microbeads are present at a high density to give high retro reflectivity.

21. A garment according to any one of claims 18 to 20, in which the microbeads are so selected and dispersed as to afford a wide angle retro reflectivity.

22. A method for facilitating visibility of objects in obscuring conditions comprising applying to the objects a retroreflective facility and providing infra red illumination for detection of retroreflected infra red radiation by an infra red imaging device.

23. A method according to claim 22, in which the infra red imaging device comprises a CCD camera.

24. A method according to claim 22 or claim 23, in which an optical system includes an infra red filter.

25. A method according to any one of claims 22 to 24, in which the infra red illumination is provided close to the optical axis of the infra red imaging device.

26. A method according to any one of claims 22 to 25, in which the retroreflective facility is afforded by an application of retroreflective tape.

27. A method according to claim 25 or claim 26, in which the retroreflective facility is afforded by a retroreflective print or coating.

28. A method according to any one of claims 22 to 27 in which the objects are garments.

29. A method according to claim 28, in which the garments are protective garments according to any one of claims 1 to 21.