A major technical advance being patented bythe Ministry of Defence could soon bring lifetime stain repellency to any fabric writesIrving Scott.

News from DERA - the Defence Evaluation andResearch Agency - based in Farnborough, Hampshire, is that their recent research intoadvanced coatings for high performance technical textiles will soon be granted full patentapprovals.

This development, which is still highlyclassified and guarded from public scrutiny until the patents are issued, is the productof several years of research into battlefield protective clothing which is resistant tothe rigours of front-line duty in Nuclear, Biological and Chemical (NBC) risk conditions.

Since the mid 1970s all western armies havebeen equipped with NBC clothing which is designed specifically to effectively block liquidaerosol droplets and chemical fumes. The garments are designed to be permeable to air forobvious comfort reasons and also to form a barrier against penetration of nuclear dust andother toxic substances.

Conventionally the barrier material used inmany forms of NBC clothing is a polyurethane foam reinforced with 'activated' carbon whichis then incorporated into a textile garment product in a multi-layer form.

The outer fabric can be polyamide, aflame-retardant polyester cotton or flame retardant Kermel/viscose chevron. Whichever basefabric is selected, further post-construction treatment by surface coating agents such asScotchgard will give a degree of water and oil proofing.

The major problem associated with NBCprotective suits is that whilst they are guaranteed for up to ten years while in theiroriginal packaging - they are only effective for at most one month when actually removedfrom the pack.

More significantly, after one week ofservice in an active NBC war zone the suits offer little or no protection and the activecarbon cannot be guaranteed to fulfil its function.

The huge costs of these protective garmentswhen in service present a major budget and supply line logistics headache for themilitary. Desert Storm illustrated this with some force - hence the DERA research projectat Porton Down, and its result is a permanently non-stain, non wettable treatment for anygarment.

MAJOR ASSISTANCE
With major assistance from a team of post-graduate research chemists at DurhamUniversity, the wet-chemicals coatings science hitherto conventionally employed to giveacceptable and effective military protection was turned on its head by the DERA teams.

Wet-chemistry treatments require a tailoredchemical solution for every blend of fibres and fabrics. This is a very expensive solutionwith obvious practical problems and was rejected.

Research turned to gas-plasma processingtechnology whereby the surface of substrates to be treated receive electrically chargedfluorinated polymers evenly and completely across the entire surface area.

The gas-plasma process, shortly to be thesubject of patent and design copyright protection, is a 'universal' treatment and it is apost-garment manufacturing process.

Complete garments as opposed to fibres orloom-state cloth are subjected to the treatment and, because the research has proved thatsurface geometry is not a limiting factor in the application, the usual problemsassociated with the partiality of spraying, brushing or dipping are removed.

GARMENT SPECIFICATIONS
This technology will have significant effects on garment manufacturingspecifications. Retailers, specifers and even ultimately, individual consumers, can beexpected to call for the gas-plasma treatment to be applied to ranges of garments or asingle garment.

'Stain free' for life will be the majoradvance in garment manufacturing for years. The ultimate customers will have their biggestafter-care cleaning problems removed; and, because the perfluor-alkylated long-chainpolymers are deposited at molecular thickness, a treated garment will be capable of alonger usable life. This will be well appreciated in large parts of the garment market,especially in schoolwear, non-fashion men's wear, outerwear and the corporate clothingsectors.

This development by DERA may be seen as aseriously beneficial product of research into so-called doomsday planning. One of the bestexamples yet of turning swords into ploughshares. No one will comment on the NBC aspectsof the research, but the civilian consumer market will be shaken and stirred as neverbefore.

INHERITED BENEFITS
Licences for the process will shortly be negotiated and the designers anddevelopers of scaled-up, practical, and cost effective production technology will be theultimate inheritors of the benefits to come.

Licensees for the process will also be akey component in the strongly rumoured plan to 'privatise' DERA and other agencies at theMoD. Commercial success and the stringencies of the real-life marketplace can only bringfurther patentable products in ever increasing volume.

Who the licensees will be is as yetunknown, but high street retailers will not be slow to seize the initiative of licensedaccess to the gas-plasma technology.

As Alison Knox, a leading high streetclothing designer says: "I can see some really practical benefits from a permanentlystain-free treatment. Assuming that the process does not add a fortune in cost to thegarment, or have adverse side effects on handle, drape and feel then the potential istruly enormous".

From all information currently availablethe quest for a gas-plasma licence is not a commercial race in which to receive a woodenspoon.