The EFFECT of ORIENTATION DRAWING on the PROPERTIES of PETg/PET BLEND

Abstract

Rational conditions for orientational drawing of PETg/PET polyester blend during processing into tape products are established. Tensile strength and elongation at break for all test specimens were determined according to ISO 527-2: 2012. Tensile modulus - ISO 527-1: 2019, specimen density - PN-EN ISO 1183-1, change of linear dimensions of specimens - ISO 16012: 2015. It was found that the introduction of PET into PETg leads to an increase in tensile strength of the blend, which is probably due to the process of orientational crystallization of PET. When the orientations are higher than 5.5 times in the PETg /PET mixtures, cavitation foaming occurs, which leads to a decrease in the blend density, its turbidity and a decrease in tensile strength. Blends with a high content of PETg have a significant thermal shrinkage, which should be taken into account when processing and applying these polymers. Physical and mechanical properties of PETg/PET polyesters blend with different ratio in the process of orientational stretching are established. The tensile strength increases with the increase drawing ratio for blends with high PET content due to its orientation crystallization. The phenomenon of cavitation foaming in polyester blend with draw ratio more than 5.5 times is found, which is accompanied by a decrease in the density of the samples and their tensile strength. Presence of PETg in PET matrix decrease tensile strength and elongation and significantly increase thermal shrinkage. Low elongation at break found for PETg/PET blend specimen without orientation which increases dramatically with low draw ratios and then decrease with higher drawing ratio. The technological modes of realization of cavitation foaming for the PETg/PET mixture at orientation drawing ratio above 5.5 due to the different phase structure of the components of the mixtures have been established. The introduction of PETg into PET leads to a significant increase in thermal shrinkage and reduces the physical and mechanical performance of oriented products.