Volume 8, Issue 1

The impact of mass of kapas and its fibre properties on fabric quality has been studied using four different carded yarn samples namely ‘Below 100mg’, ‘100-150mg’, ‘151-200mg’ and Normal sample of 50 s Ne for the production of handloom fabrics. All the fabric samples have been produced with uniform process parameters and their tested as per the standard procedure for durability, aesthetic characteristics, and colour fastness properties. It is observed that the mass of kapas and its fibre properties significantly affect the fabric quality.

This paper presents an automatic vision-based system for unsupervised detection and classification of spliced yarn joints. In the splice detection process, a competitive learning method based on an LBG algorithm is used. In the splice classification process, a dynamic time warping (DTW) algorithm is used to classify the extracted splice joint into one of three categories, based on the degree of similarity between the spliced joint and the nonspliced remaining part of the same yarn. The use of DTW in the classification makes the proposed method adaptable to different types of yarns. Consequently, this method might be universally applicable for the classification of all spliced yarn joints. The proposed method has been evaluated using three types of experiments, yielding a promising result.

In this paper, the tearing properties of a multi-axial warp knitted fabric produced with glass filaments and coated with PVC resin are presented. The typical tearing load-extension curves and influences of the different tearing testing conditions are analyzed. The results show that the tearing properties of the coated multi-axial warp fabric are different from those of the coated woven fabrics and that they depend on the tearing directions and tearing methods. The trapezoidal method and tearing tests along diagonal directions give higher resistance against tearing propagation.

Based on uni-axial tensile testing, the performances of bi-axial warp knitted PET/PVC flexible composites has been analyzed in seven in-plane directions, i.e., 0°,15°,30°,45°,60°,75° and 90°. The crack propagation of each sample has been observed and analyzed by evaluating the influence of the crack length and direction under uni-axial testing. The results show that bi-axial warp knitted coated fabrics present a strong orthotropic behavior and that the tearing strength depends on the initial crack orientation and length. Regardless of the crack length and orientation, the propagation is always perpendicular to the tensile loading direction.

This study has shown that image analysis has great potential to provide reliable measurements for detecting defects in knitted fabrics. Using the principles of image analysis, an automatic fabric evaluation system, which enables automatic computerised defect detection -(analysis of knitted fabrics) was developed. On-line fabric defect detection was tested automatically by analysing fabric images captured by a digital camera. The results of the automatic fabric defect detection correspond well with the experimental values. Therefore, it is shown that the developed image capturing and analysis system is capable of on-line detection of fabric defects and full control in the knitting machine (for example, by stopping the circular knitting machine as soon as a defect is acquired by the digital camera).

This work reports on research being carried out in thermal comfort in smart and adaptive knitting structures (functional structures). The total comfort of a garment comprises not only the sensorial, thermal and physiological component, but also aesthetic, colour and size aspects, which make up the so-called psychological comfort. It should be noted that when buying a piece of clothing for daily wear, the psychological point of view may well play an important role. Nevertheless it is the thermal and physiological components which have historically been the primary functional component of clothes, since they must protect us from cold and heat and, simultaneously, have to allow an appropriate moisture and heat transfer through the different layers. Thermal comfort is characterised by three important properties: · Thermal resistance; · Thermal conductivity; · Thermal absorptivity. In this research we present the engineering design of these principal thermal properties in functional structures and we propose three new equations that simulate the reality of the behaviour of this knitting structures.