Some Properties of 50/50 Nylon/Cotton and Nylon/Viscose Blends: Part I: The Strength and Air Permeability of Fabrics Varying in Construction

About thirty experimental nylon/cellulosic fiber blend fabrics were constructed to study the effects of the following variables: cotton vs ordinary and modified viscose; intimate vs plied yarn blends; weave, yarn number and spacing, and twist; untreated vs heavily resin-treated samples, with various add-ons of softener. The grab strength of the nylon/cotton intimate blend fabrics could be related to the weight of the stressed yarn system by the equation: Grab strength, lb = 0.0087 den/in. — 15 (corr. coeff. 0.95) There was no significant effect of the fabric construction or resin treatment on this relationship. The points representing nylon/viscose intimate blend fabrics were generally quite close to this line, but those for nylon/cotton plied yarn blend fabrics followed an equation with the same slope but with an intercept of +30; thus, at an average, they had 45 lb more grab strength than comparable intimate blend fabrics. The tear strength of the untreated, nylon/cotton intimate blend fabrics followed the relationship Tear strength, lb = 0.00036 den/in. — 0.3 (corr. coeff. 0.74) The points above this line were generally those representing satins and relatively coarse yarns; those below, 2/1 twills and plain weave fabrics and/or relatively fine yarns. The same slope with an intercept of −2.5 lb and a correlation coefficient of 0.91 were obtained after resin treatment, indicating an average strength loss of 2.2 lb, and a much smaller effect of fabric construction. The nylon/cotton plied yarn blend and the nylon/viscose intimate blend fabrics had higher tear strength than their nylon/cotton intimate blend counterparts. The air permeability of the blends which contained viscose was generally higher than that of their cotton-containing counterparts. In all blends, the air permeability was reduced by the resin treatment. Within each blend, the air permeability was essentially a function of the closeness with which a fabric construction approached the limit of weavability. Relatively low twist (twist multiplier 3.05) lowered the air permeability but did not affect the grab or tear strength in these fabrics.