Kevlar multifilament

LMP, the construction and applications of which have been described elsewhere is some detail (1-3). In the present work, LMP treatments have been performed on substrates of aromatic polyamides, notably du Pont "Kevlar". The excellent mechanical properties of Kevlar fibers and of structures based on this fiber have been well documented, as have some of their shortcomings (4, 5). Our concern is with the apparent difficulty of bonding Kevlar with adhesives of the epoxy and triazine type. A comparison study was carried out for bond strengths in laminates based on control Kevlar multifilament cloth and for similar structures using Kevlar subjected to plasma treatments. The results of that study are reported here, along with complementary data on the various effects of plasma treatment. 

Recently, Caster et al. described the surface modification of multifilament fibers such as nylon or Kevlar [70]. Coating techniques using preformed ROMP-based polymers and process contact metathesis polymerization (CMP), initially described by Grubbs et al. [71], were both used. The latter involves a procedure where the initiator is physisorbed onto the surface of a substrate and fed with a ROMP-active monomer that finally encapsulates the substrate. These modified fibers showed improved adhesion to natural rubber elastomers. 

Most technical yams for reinforcement are based on continuous multifilament yams having linear densities typically in the 1100 dtex (1000 denier) region in singles or doubled configurations. The number of filaments per yam will vary between about 140 and 200 for melt-spun nylon 6.6 and polyester to >500 for high tenacity viscose and other wet-spun fibres, including the aramids. For instance, Kevlar 29, suitable for rubber reinforcement, is available as a 1670 dtex yam with 1000 filaments. "... 

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