Tensile tests on acrylic yarns and fibres extracted from various steps of textile processing reveal mechanical and thermal modifications due to the manufacturing operations. To examine this, viscoelastic modelling based on mechanistic models for fitting experimental data of tensile tests were investigated. Crystalline/amorphous distribution was assessed by the differential solubility technique, and the models account for changes in property values due to microstructure modifications.

The water vapour permeability resistance of a commercial polytetrafluoroethylene (PTFE) membrane was measured under reduced pressures at constant temperature. The PTFE membrane is hydrophobic, wind-proof and water vapour permeable. The device used for this investigation consisted of two concentric cylinders; one was filled with distilled water, the other was kept at a low water vapour concentration which was 20% relative humidity at 293 K by means of a potassium acetate saturated solution. The apparatus was devised so that no air layer existed on either side of the test specimen. The water vapour permeability resistance of the microporous PTFE was almost unchanged at the reduced pressures examined. To confirm the present experimental method, an additional measurement was made with the use of a polyester (PET) net, which was selected because of its open structure. The water vapour permeability resistance of the PET net decreased with decreasing atmospheric pressure. The reasons for this difference are discussed in relation to the sizes of the micropores and the mean free path of the water vapour molecules.

Previous work on the morphology of naturally coloured green cottons has suggested that the secondary wall of the fibres consists of alternate layers of cellulose and a waxy organic substance called suberin. The work described in this paper has shown that modem varieties of green cotton do contain a large proportion of suberin. Data from fibre swelling is consistent with alternate layers of suberin and cellulose in the secondary wall. The naturally coloured fibres have a lower tenacity and work of rupture than conventional white fibres although they have an acceptable level of textile properties. The crystallinity of the coloured fibres is lower than of white cotton, but the cellulose has the Cellulose I structure normally found in cotton.

Accelerated flex fatigue testing has been carried out on gel-spun ultra-high modulus, high-performance polyethylene (HPPE) fibres, under the influence of a fixed applied tension, and over the tempe...

Paracrystalline as-spun fibres of low orientation were identified previously as suitable precursors for the production of drawn fibres of very high tenacity. This study is concerned with the effect...

Part I [1] described a basic bulking method. This paper deals with the question of incorporating the technique in a conventional ring spinning process.

Abstract In Part I of this work, a framework for the design of efficient small-lot weaving-preparation systems was presented. The design objective was to specify the lowest-cost system that will meet the desired production goals for a given product mix. A key element of this framework is the analysis engine, which evaluates the performance of candidate systems in the light of production targets and generates information about the direction in which to evolve the design. In this work, it is shown that simulation methodologies and sensitivity analysis can be used to perform the analysis-engine function. Two candidate systems representing possible points in the over-ail design space are evaluated to determine if one has an advantage in producing small lots. In addition, information gained from the analysis procedures can be used to point to further improvements in system performance for a relatively small increase in capital expenditure.

High-speed cine-photographic observations were made of fibres in flight and of their deposition onto the forming end of a yarn in the disc-spinning process. Analysis of the photographs was carried out in order to determine the degree of straightening and the parallelism of the deposited fibres. It was found that the average speed of fibres leaving the opening-roller unit was significantly lower than the surface speed of the opening roller. The leading ends of fibres were noted to have decreased in speed before being accelerated to the disc groove, where they were deposited onto the forming yarn tail. The trailing ends underwent a constant acceleration to the point of deposition. When the leading end of a fibre first contacts the yarn, its inclination to the yarn axis can he used to define its position in space. Furthermore, the inclination to the yarn axis of the velocity vector of the trailing end of the fibre can be used to define the direction of the velocity. It was found that, on average, when the le...

A model was developed to support a structured approach to the investment-decision process in the weaving industry. This model assists the initial investigation through an investment guide. It enabl...

(1996). Airborne Dust in Wool Textile Mills-Reply. The Journal of The Textile Institute: Vol. 87, Issue 1, Parts 1 and 2, pp. 240-240.