Production and Characterisation of the Physical and Mechanical Properties of Recycled PP Fibers
This chapter explored the industrial feasibility of using melt spinning and hot drawing process to produce PP fibre under factory conditions instead of laboratory conditions. Virgin PP fibres of high tensile strength and Young’s modulus have been successfully produced by this method. However, the production of recycled plastics with sufficient mechanical properties is still a major challenge due to degradation during their service history and heat processing stages. The aim of this chapter is to improve the tensile strength and Young’s modulus of fibres from recycled PP produced through the melt spinning and hot drawing process, and establish a relationship between mechanical properties of PP fibres with their crystallinity, crystal structure and orientation. Besides 100% recycled PP fibre, 50% of virgin PP and 5% of HDPE were mixed into the recycled PP fibre to produce 50:50 virgin-recycled PP fibre and 5:95 HDPE-recycled PP fibre, respectively. The mechanical properties of these recycled fibres produced by the melt spinning and hot drawing process were presented and compared with the virgin PP fibre. The effects of 50% of virgin PP and 5% of HDPE on fibre from recycled PP were studied in terms of crystal structure and crystallinity by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS).