IMPROVEMENT OF TEAR RESISTANCE OF COATED FABRICS.
Final technical rept., 3 Feb 66-1 Feb 67,
MELPAR INC FALLS CHURCH VA
Pagination or Media Count:
A series of 2 ozsq yd, plain-weave nylon fabrics of varying thread count and degree of yarn twist impregnated with varying amounts of two standard primer-adhesive formulations were mechanically tested to determine the relative importance of fabric construction and primer compound variables in tear strength retention of coated fabrics. Primer modulus, amount of primer deposited and degree of yarn twist were found to be important initially. The loss of tear strength of the primer-treated fabrics was found to be due mainly to the immobilization of the fabric yarns by virtue of the bonding action of the primer compound at their points of intersection. The strength of this bond appeared to be a direct measure of the restraining force responsible for the yarn immobilization and was determined by means of a yarn pullout test developed for this purpose. The degree of restraint necessary to cause loss of fabric tear strength was found to be quite small. The additional restraint imposed by subsequent application of coating compound to the fabrics in a manner which allowed complete penetration was so great as to overshadow all other effects, even when the coating compound modulus was minimized by undercuring, and coating adhesion was low. Good tear strength retention at a low rate of tear was achieved with a composite coating embodying a modulus gradient, such that uncured elastomer filled the fabric interstices. Author
- Coatings, Colorants and Finishes
- Elastomers and Rubber