Effect of Rubber Hardness and Thickness of the Main Squeezing Roll on Sized Yarn Performance in Warp Sizing: Experimental and Comprehensive Evaluation

The main squeezing roll plays a pivotal role in the effective warp sizing. This study examines how rubber hardness and thickness on the main squeezing roll affect sized yarn performance. In the experiments, 14.8 tex cotton compact-spun yarns were sized using a single-sizing-roll triple-roll-type sizing machine, with the main squeezing rolls configured with different rubber hardness (70 SH, 77 SH, 84 SH) and thicknesses (16 mm, 20 mm, 24 mm). Results showed that increasing rubber hardness raised size pick-up, breaking force, abrasion resistance, and residual breaking force after abrasion, but reduced breaking elongation and increased hairiness. Additionally, as rubber thickness increased, size pick-up first decreased and then increased, while breaking elongation and abrasion resistance initially improved before declining, and hairiness progressively increased. Analysis of variance (ANOVA) confirmed that both rubber hardness and thickness significantly influenced size pick-up, breaking force, breaking elongation, abrasion resistance, and hairiness of sized yarns. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to evaluate sized yarn performance, revealing optimal results at rubber hardness of 84 SH and thickness of 16 mm. This study offers a theoretical basis for understanding how rubber aging causes fluctuations in sized yarn performance.