Optimization and validation of heat-setting process of cationic dyeable polyester knitted fabric using Box-Behnken design

Purpose This study aims to optimize and validate the heat-setting process parameters of cationic dyeable polyester (CDP) knitted fabric to enhance its dimensional stability. Design/methodology/approach The experiments were designed using the Box-Behnken design, with temperature (°C), time (sec) and stretch (%) as key independent variables. The responses analyzed included grams per square meter (GSM), dimensional stability in the course and wales directions and bursting strength of the heat-set knitted fabric. Findings The optimized heat-setting parameters significantly influenced the dimensional stability, GSM and bursting strength of CDP knitted fabric. The optimized heat-setting parameters identified for cationic dyeable interlock knitted polyester are a temperature of 170.5 °C, a time of 90 s and a stretch of 8% in the course direction. GSM decreased primarily with stretch (C), while dimensional stability was mainly affected by temperature (A), time (B) and stretch (C), with minor interactive effects. Bursting strength improved with temperature and time but decreased with excessive stretch. Overall, temperature and stretch played a key role in fabric weight and stability, whereas process time mainly influenced mechanical strength. Originality/value Polyester and CDP exhibit differing thermal responses. While extensive research has been conducted on optimizing the heat-setting process for 100% polyester, studies specifically addressing 100% CDP remain limited. Moreover, previous research on CDP has focused on the effect of adding modifiers with a sulfonate group and their impact on structural changes and thermal properties. This highlights a gap in existing knowledge. This study aims to systematically investigate the influence of these parameters on the dimensional stability, weight of fabric and mechanical properties of 100% CDP interlock knitted fabric.