Today BCF Polypropylene (PP) yarn is used in machine made carpet as pile yarn. This yarn is subjected to heat setting process together with Frieze treatment for creation of resiliency and special effects. The aim of this research was to investigate the physical and crimp properties of BCF PP pile yarns subjected to Frieze treatment process. In this research,according to the experimental analysis design carried out by Design Expert software, the level of 3 parameters including, temperature of heat setting, vapor pressure and over feed ratio of Frieze process are determined.
Regarding to the obtained results by Design Expert software, 14 kinds of Frieze yarn sample along with a control yarn is produced. The physical properties of yarns including: linear density, shrinkage, crimp contraction are measured. Analyzing the experimental results shows that increasing the temperature of heat setting causes linear density and crimp contraction to be increased but shrinkage decreased.