Abstract: Multifilament bundles are impregnated with an ultraviolet curable resin to form a composite material suitable for use as a strength member in cables and other applications. The inventive coatings obtain good wetting of the filaments, allowing rapid penetration into the roving or yarn. A much faster coating and curing operation is obtained as compared to prior art methods. Fiberglass strength members made by this technique are especially advantageous for use in optical fiber cables where high strength and a low thermal coefficient of expansion are desired, as well as nonconductivity to protect against lightning strikes.

Abstract: The specification describes radiation cured coatings suitable for coating fiber lightwaveguides. The coatings are relatively low modulus materials that remain rubbery throughout normal environmental temperature ranges. An exemplary coating composition comprises an oligomeric resin, which is a condensation product of a mixture of polypropylene glycols and two units of a O-hydroxy-ethylacrylate N-C aliphatic urethane, mixed with an oligomeric liquid which is a dimethylacrylate of a polyethylene glycol of molecular weight larger than 600, a monomoneric triacrylate, such as trimethylolpropane triacrylate and a photoinitiator. The coatings are free of nomoneric ingredients.