Comparison of tensile properties of needle punched nonwoven fabric produced by bi-directional and unidirectional barb needles employing response surface methodology

Abstract

In production of needle punched nonwoven fabrics, 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 fabric). In this study, the test specimens were prepared by two type of needles in an industrial needle machine. Fibre displacement at fabric cross-section was examined by optic and scanning electron microscopy for two types of needles. An experiment with 190 samples was produced using the response surface methodology and optimal design with two quantitative factors, including the number of strokes per minute and needle penetration depth, and one qualitative factor containing needle types. In addition, six responses were measured and reported in the machine direction and cross direction, including breaking load, extension, and tenacity. According to the findings, the tensile characteristics of non-woven (NW) fabrics generated produced by bi-directional barbed needles were higher than those produced by unidirectional barbed needles.