Enhanced Knittability of Paper Yarn from the Swedish Forest by Using Textile Finishing Materials

Abstract

Friction between Swedish paper yarn and needles is a limiting factor that—together with the low yarn flexibility—is hindering the knitting and use of paper yarn as a sustainable textile material. To enhance the knittability, paper yarn was coated with textile finishing materials. The effect of six different textile finishing materials used for textiles processing (three different silicone-based, wax, glycerol, and soap) was evaluated. The treatment evaluation was done by determination of the friction coefficient, tensile testing, and knitting. The friction coefficient was determined by an adaption from the ASTM D3108-07 Standard Test Method for Coefficient of Friction, Yarn to Solid Material. The adaption meant using a specially designed rig, making it possible to simulate the yarn/needle friction during the knitting process and use a tensile testing machine to determine the friction coefficient. Through using the same angle for yarn movement during the knitting process in this adaptation, the effect of the flexibility of paper on the friction coefficient is integrated. Tensile testing was performed using a Tensolab 2512A/2512C electromechanical tensile tester, and knitting tests were performed using a Stoll CMS 822 HP knit and wear flat knitting machine with the E5.2 gauge. The results show that knittability is better for the yarns with lower coefficients of friction and can also be enhanced by spraying with regular water. The tensile properties of the yarn is degraded by the treatments. The wax- and soap-treated yarns were most challenging to knit. The silicone-based and glycerol-treated yarns showed enhanced knittability, where the glycerol treatment results in more protruding fibers compared to the other treatments. All treatments reduced the roughness in the feel of the knit. The results indicate that the Swedish paper yarn can be a future sustainable complement to polyester and cotton.

Comfort properties of fabrics knitted from a two-ply yarn derived from abacá and cotton

“…The maximum moisture capacity (MMC) was determined with reference to the test described by Tang et al 22 In the test, a specimen with dimensions of 100 mm  100 mm was placed into a tank of water for 24 h. The fabric was then taken out with tweezers and hung on a rod vertically until there was no water dripping within a 30-second interval. The value was calculated according to equation (7).…”

“…Â 100 (7) where W dry is the weight before the specimen was placed into a tank of water (g) and W wet is the weight when there was no water dripping within a 30-second interval (g). The drying rate (DR) and drying time (DT) were measured according to ISO 17617-2014 A1.…”

“…However, it is stiff and difficult to knit. 3,5,7 Therefore, because of these negative characteristics, the manufacture of knitted fabrics from paper yarn is not widespread. The end-user characteristics of fabrics knitted from paper yarn, such as comfort properties, are not completely clear.…”