Experimental Study on Draw-Ability of Filament Yarns Produced from Recycled and Bottle Grade PET

In this study, draw-ability of continuous yarns (filament) from recycled bottle grade PET (R-PET) and new bottle grade PET (BG-PET) were compared. Virgin fiber grade PET (FG-PET) was used as the control. Spinning and draw machine were performed separately in this study. The draw ratios were 2.8, 3.0, 3.2, and 3.55. It was found that higher draw ratios result in higher density and crystallinity for all samples. This increase was larger in the case of FG samples, especially at higher draw ratios. This suggests that crystallization ability in the drawing process for the recycled polymer is weaker than the new polymer. Higher initial modulus of yarns produced at higher draw ratios is confirmed by the increase in their crystallinity values. Higher values of apparent crystal size of R-PET and BG-PET samples than those of FG-PET samples are in accordance to their initial modulus changes. In the draw ratio of 3.2, R-PET converted to Fully Drawn Yarn (FDY). In this draw ratio, tenacity of R-PET (3.18g/den) showed 11% higher value compared to that of FG-PET (2.83g/den). The drawn R-PET filament yarn presented desirable properties compared to the drawn FG-PET yarn. This might be attributed to the higher intrinsic viscosity and birefringence of the R-PET yarn. As a result of an increase in draw ratio, there is an advanced considerable increase in the tensile strengths and initial modulus of filaments in all samples..