Modelling pore size distribution function of twist-texturized yarns and single-jersey knitted fabrics

Abstract

Pore sizes on the micrometre scale are a critical factor influencing the fluid transport properties of textiles. Consequently, the pore size distribution function is a desirable parameter in the design of textiles for technical applications. However, the experimental determination of pore size and its distribution can be challenging, costly, or impractical. Knitted fabrics offer a wide range of porosity and pore size distribution properties. While statistical models have shown reasonable accuracy in predicting pore size distributions in nonwovens and filter media, no equivalent model exists for twist-texturized yarns and single-jersey knitted fabrics. This study presents a hierarchical pore model for single-jersey fabrics. The model uses a log-normal distribution for the intra-yarn pores in the yarn and cylindrical pores for inter-yarn pores between the yarns in the fabric. With these two pore sizes, the model quantitatively characterises the porous structure of the fabric. Initial validation of the model for intra-yarn pores on four yarns of different fibre finenesses shows that the model can cover the influence of different fibre counts. For the validation on the fabric scale, two tomography datasets of single-jersey knitted fabrics show that the presented model can capture the effect of different fabric structures. A parameter study visualises the effects of both yarn and knitting parameters on the pore size distribution function of single-jersey knitted fabrics. The mean pore sizes of the fabrics are given. The results deepen the understanding of the porous properties of knitted fabrics and provide a valuable direction for structural fabric development on knitting machines.