Influence of Aging on the Physical Properties of Knitted Polymeric Materials

Abstract

Nowadays, as consumer expectations have increased worldwide, the importance of polymer materials performance has been raised to a new level. Efforts are required to produce a high-quality product that maintains its quality despite aging factors in certain geographical locations. In the experimental part of this study, polyester materials produced from conventional and recycled yarns, further intended for the production of sportswear, were exposed to natural weathering. Before and after the exposure, the following material properties were investigated: material surface appearance, material thickness, mass per unit area, horizontal and vertical density, surface roughness, tensile properties (force at break, elongation at break), water vapor permeability, liquid dispersion and drying of the material. The results indicate that the surface mass and thickness of all exposed polyester materials decreased after aging due to material shrinkage. The results indicated that prolonged aging negatively affected the values of elongation and force at break. The recycled material exhibited the highest overall decreases in elongation and force at break, but lower surface roughness. In addition, recycled material exhibited a shorter drying time than that of conventional material, both before and after aging.

Influence of Yarn and Fabric Properties on Mechanical Behavior of Polymer Materials and Its Retention over Time

“…With this material, the elongation at break in the course direction is 2.5 times higher than in the wale direction. This noted difference is in line with a previous study [24], which has shown that there is a significant difference in elongation at break tests in the directions of the courses and wales of polyester materials. In the case of the material to which elastane has been added, the behavior of the material structure changes so that the differences in the values for the different directions of the material are less pronounced.…”

“…While interest in sports-related materials is increasing, the literature review pointed out that specific aging protocols for functional sportswear are lacking. Previous studies have shown that aging has an effect on certain physical–mechanical characteristics, but it is concluded that these changes should not significantly affect the athlete’s performance [ 24 , 25 , 26 , 27 ].…”