Search results

Uses a general large displacement beam theory to formulate a finite element‐based numerical method for simulating fabric drape, manipulation and contact. Presents numerical results corresponding to real fabric materials. Shows a broad class of fabric mechanics problems including how these effects can be solved.

Applies a sound theory to predict in‐plane bending deformation of flexible beams under large overall motions to predict the locus of the trailing end of the ply during wiping off the conveyor surface of the layup machine. A computerized numerical solution was used to estimate the locus of the trailing end of the ply for seven woven fabrics of wide range of thickness, weight, and bending rigidity. The least square method was employed to obtain regression relationship between the horizontal and vertical displacement of the trailing end of the ply for each of the seven fabrics. The regression equations and the slat height were used to calculate the minimum gap between two slats of the stacking conveyor so that the fabric trailing end does not touch the top or the side surfaces of a slat during the layup process.

Describes one of the most frequently occurring processes in automated garment manufacture – the picking and placing of fabric panels. This can be carried out using pinch grippers which comprise two pegs that are pushed down on to the top of the fabric. The pegs are then brought together so that the fabric buckles up and is secured between them. It is essential that this operation has very high reliability and repeatability as an error can result in distorted, badly placed or misaligned fabric panels, which would then lead to the production of a faulty garment. The important parameters are the frictional characteristics of the peg surface/supporting surfaces combined with the weight and bending stiffness of the fabric, the opening distance of the pegs and the downward pressure applied to them. Describes a model for these relationships and uses experimental data on frictional and bending properties to predict the gripping behaviour for a given gripper design and gripping strategy. The predictions are compared with experimental results.

Understanding the behaviour of fabric in bulk form is necessary for the optimum design of automated material handling systems. Considers the bulk behaviour of stacks of cut fabric parts; the objective is to predict the bulk behaviour of stacks under compression. Uses a single ply fabric compression model developed by De Jong, Snaith and Michie to develop a compression model for stacked fabric.

There are many instances in automated garment manufacture where static fabric panels have to be picked up and placed onto a moving surface such as a conveyor. The techniques used and, in particular, the effects of lowering a fabric held by its upper edge, onto a moving horizontal surface are described. The particular case of a non‐symmetrical piece is analysed in detail.

Introduces and evaluates a finite‐element computer model which predicts the bending behaviour of fabric in contact with a surface, in order to optimize the design of equipment used for automated processing of apparel. Describes how simulations were executed for all combinations of eight fabrics and three contact surfaces, and presents the experimental results obtained for similar conditions and fabrics. Proves the validity of the computer model by comparing the experimental results with those obtained by simulation. Describes how the computer model could be used to choose the optimum diameter of a fabric feeder picking roller.

Describes the redesign of the Clupicker, a ply separation device used in the textile industry, based on design for assembly techniques. Presents design for assembly (DFA) guidelines. Describes Boothroyd's Systematic DFA Methodology and Zorowski's PDM program, and analyses the design of the Clupicker using both of these methods. Presents and analyses a proposed redesign of the Clupicker based on DFA techniques.

A robotic system for testing fabrics under low‐stress conditions has been developed at UMIST. This system is capable of conducting all the mechanical tests on a single piece of fabric, without operator intervention, thus eliminating human‐related errors. Looks at test control strategy and acquisition of force and deformation data, from the viewpoint of process control in garment assembly.

This paper aims to investigate the elasticity of hemp woven fabric under action of bending force, before and after washing treatment.

Bending elasticity was monitored in three different ways: through the value of bending modulus, on the basis of fabric's resistance to creasing expressed through the value of quality number, and through the value of bending deformation components. On the basis of the results obtained from the mentioned three types of investigations, the complex criterion of quality of washed and unwashed hemp fabric, from the aspect of their elasticity, was formulated.

Values of complex criterion as well as the values of bending modulus, quality number and total recurrent deformation pointed to the conclusion that investigated hemp fabric has, not good, but satisfied bending elasticity, especially after washing treatment. The values of bending deformation components served for establishing Frenkel's model of elastic behaviour under action of bending force of washed as well as unwashed hemp fabric.

Shows that the way on which Frenkel's model was established might be interesting because of its simplicity.

Provides information on the elasticity of hemp woven fabric before and after washing.

Gives a review of the various methods which have been developed to measure the stiffness of fabric and describes a new method. This new approach enables the testing of knitted fabrics which are difficult to test using the cantilever system. The inter‐operative reproducibility of the new instrument is compared with that of the cantilever method and the drape meter. Also reports inter‐laboratory comparisons on woven fabric and on knitted fabric, the latter having been measured on a KES‐F system.