Influence of Aging on the Physical Properties of Knitted Polymeric Materials

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.