A comparative study of physical properties of nonwoven fabrics produced by uni- and bi-directional needles using response surface methodology

Abstract

In the production of needle-punched nonwoven fabrics, the direction of needle barbs is towards the tip of the needle. When the needle penetrates into the fabric, the barbs carry some fibres into the fabric and when it returns the barbs are empty. This means that, the needle works when it penetrates into the fabric and doesn’t work when it returns. Using a bi-directional barb needle in the needle-punch process was proposed as an idea with the theory that, the needle also works when returning (leaving the layer). This study investigates the physical properties of needle-punched nonwoven fabrics produced with unidirectional and bi-directional needle types. Effects of needle penetration depth (NPD), strokes per minute (SPM), and needle type (N1, N2) on properties such as gram per square meter (GSM), thickness, fabric density (FD), and static puncture resistance (SPR) are examined. An experiment with 19 runs was designed using response surface methodology and optimal design with two quantitative factors, including NPD and SPM, and one qualitative factor containing needle types. In addition, four responses were measured and reported, including GSM, thickness, FD, and SPR. Test results show that needle N2 produces a fabric with lower FD, higher GSM, thickness, and SPR in comparison to needle N1, and was selected in optimization process with a desirability value of 0.872 against 0.688 for needle N1. The improved fabric properties of needle N2 may be exploited for the economic benefits of the nonwoven fabric producers or textile industry.