Band 5, Heft 4

Data analysis of a fabric.s compression properties can only be done when the limits of compression are known. The best formula is van Wyk.s, although the meaning of the physical parameter is still not clear. On the basis of van Wyk.s equation, a study of the compressibility of woven fabrics can be initiated in partnership with Pierce, Kemp and Hamilton.s approach for circular yarns and the flattened yarns of a fabric under pressure. Neural network models promise to solve the drawbacks of de.Jong.s and other models. The fit of the pressure-thickness relationship may be improved by using exponential function and the Iterative method, such as Marquardt.s algorithm for evaluating compression properties. Back-propagation promises to give better results, since the KESFB3 compression measuring instrument works by minimising error levels. The optimisation of low-stress mechanical properties is possible by using trained networks, and this venture forms an absolute method for comparing the functional properties of fabrics.

A new method to characterise the coefficient of friction of textile fabrics is proposed. The principle is based on the dry clutch, where an annular shaped flat upper body that is kept still, rubs against a lower flat surface, which rotates around a vertical axis at a constant angular velocity. Friction coefficient between the two contacting surfaces is then proportional to the level of the dragging torque between them, measured by means of a precision reaction torque sensor. Contact pressure is constant, given by the own weight of the upper body. The signal from the torque sensor is digitalised through an electronic interface and fed into a PC where friction coefficient is worked out. Finally, experimental work is reported.

Although modern sailcloth materials are extremely complex, a considerable degree of disorder is still present in the evaluation of their quality, and experience is still the most important parameter in assessing a product. For those reasons, precise characterisation and evaluation of modern sailcloth is a topic that requires systematic investigation, both in view of defining relevant characteristics & parameters, and in defining and adapting adequate testing methods and procedures & evaluation of results. The paper presented here is a contribution to the scientific and professional approach to the topic.

Clothing for garments is designed to meet both the safety and the comfort of human beings. Porosity is considered to be one of the basic features representing a textile structure. The properties of fabrics were analyzed by determining the efficiency of fabric porosity. The woven fabric multi-layer structure, the warp and weft densities, and the type of weave are factors of a woven fabric, which as porous material enables to transmit air, heat energy, and liquid perspiration. Several methods considering thread distributions have been developed to determine the woven fabric’s porosity. A mathematical model based on an ideal geometry of the porous structure of a multi-layer woven fabric has been developed.

‘ProKNIT’ is the result of a project based on the consideration that knitted fabrics shrink in both directions, or that some of them shrink in one direction but expand in another. This shrinkage and extension is not proportional; it varies greatly depending on the type of knitted fabric. However, one value that always changes by increasing upon fabric shrinkage is the fabric’s weight. Increases in weight from shrinkage will not only increase the cost of production but may also affect the final product in a number of ways. Therefore, a program that would help to avoid problems of this nature could be created which would predict the weight of the knitted fabrics in different relaxed conditions, by using appropriate variables such as knitting machine gauge, yarn count, type of fabric, fabric loop length, tightness factor and courses & wales per unit length, but would not be too difficult to operate. This is how ‘proKNIT’ came about. The first part of the word ‘pro’ derives from the Greek meaning ‘before’; therefore, the name of the system appropriately refers to the estimations made before a knitting fabric is produced.

Poly (styrene-co-butyl acrylate) latex was prepared with a 70:30 weight ratio of styrene to butyl acrylate. Various weight percentages of cornstarch were incorporated into the prepared copolymer latex. Polyester nonwoven fabric reinforced-cornstarch-filled copolymer latex composites were manufactured by the impregnation method. The pickup ratio of latex to fabric was maintained at 3.2:1. The composites’ physico-mechanical properties, percent water absorption and percent thickness swelling were studied. The manufactured cornstarch-filled composites were evaluated for their ability to retain their shape after being moulded to the desired shape by measuring the percentage area, shape retention, hardness and resilience. It was observed that the manufactured thermoplastic composite specimens retained or increased their mechanical properties up to 20 wt% cornstarch loading.

This paper presents an automatic method that can measure the thickness of three-dimensional (3-D) braided composite preforms. The thickness of 3-D braided composite material preform is an important parameter of 3-D braided composites. With the development of 3-D braided composite technology, an automated measurement technology for thickness of braided composite preform has become an importantgoal. The objective of this paper is to present an automatic measuring system. The system we devised consisted of a computer, a proximity sensor, a pressure sensor, an analog-to-digital converter and pulse motor, etc. The measuring principle and results are discussed in the paper. The system was tested on both carbon and glass fibre preforms. We obtained very encouraging results. Experiments showed the pressure and eddy current resistance value are important parameters for measuring the thickness of 3-D braided composite material preforms. The measuring precision is higher when the pressure value ranges from 0.6kg/cm 2 to 0.8kg/cm 2 and the eddy current resistance is 2kΩ for preforms made of carbon-fibre than of other substances.

The Egyptian government has shown substantial consideration regarding the rehabilitation and restructuring of inefficient companies in the public sector with regard to converting them into profitable companies which will be ready for privatisation. Furthermore, textile manufacturing can be considered as one of the biggest industries in the public sector. So, the idea of showing how textile manufacturers in the public sector can be developed to meet the requirements of marketing and product strategies has been initiated. This study has been prepared to assist in developing one public-sector textile manufacturer to meet the requirements of a quality management system, which in turn reflects on improving the mill performance. Applying the technical means of quality management in the spinning industry, preparing the spinning industry for quality agreements, requirement profiles for different yarn quality characteristics and types, spinning quality problems and solutions, and optimum yarn quality at optimum costs are the key areas which are covered in a unique manner.