Automation in Measurement of Inverse Creep in Textile Yarns

From decades Creep has been known and studied for textile materials. In comparison, a newly observed phenomenon of inverse creep seems not to have received much attention. A new instrument has been fabricated to measure creep and inverse creep in textile materials particularly yarns. Creep and Inverse creep measurements of few of the textile yarns like nylon multifilament yarn, Polyester multifilament yarn, Cotton and wool yarn at different levels of stress have been studied, using the new instrument along with Transreceiver, embedded system and Personal computer the automation is achieved and results are reported in the present paper.

Features of Formation of a Multifilament Yarn from Crystallizing and Amorphic High-Heat Resistant Thermoplastics

In laboratory conditions, the molding process was simulated by extrusion of a multifilament yarn with a diameter of the monofilament equal 250-350 μm from high performance plastics. The possibility of obtaining a microfilament bundle of polyetheretherketone, polyphenylene sulfide and polyetherimide using a specially made forming head is shown. The technological modes of extrusion have been worked out, which makes it possible to obtain thermoplastic fibers from the studied thermoplastics. It was revealed that the obtained microfilaments can be subjected to post-processing by cold drawing to reduce their diameter by 40-70 %.

Crimping analysis of textured polyester multifilament yarn

The properties of textured POY PES multifilament yarns are conditioned by texturing temperature, texturing speed, stretching degree and by the ratio of disc peripheral speed and yarn speed. In the paper attention is focused on crimping of yarns. New method for defining crimping limits is proposed. The method is based on the flow analysis of the force-elongation function. POY multifilament polyester yarns, having the fineness of 167f36x1 dtex were analyzed. The texturing of PES multifilament yarns was performed using different first heater temperatures (350 oC, 400 oC, 450 oC) and maintaining the constant temperature of the second heater (180 oC), then with different texturing speeds (500 m/min, 600 m/min, 700 m/min, 900 m/min, 1000 m/min, 1100 m/min), using different ratio of the disc circumferential speed to yarn speed (2.15, 2.20, 2.25) and at the extension degree of 1.665.

Influence of Weave Parameters on Woven Fabric Tear Strength

The influence of weave on woven fabric tear strength is analysed in this paper. Brierlay’s factor Fm, Milašius’ factor P and P’ and modification of parameter P made by the authors (P’weft) were used in the investigations presented. Woven fabrics of 100 % viscose multifilament yarn manufactured from the same yarns and with the same density but with seven different weaves (plain weave, weft rib 2/2, warp rib 2/2, twill 2/2, twill 3/1, basket weave 2/2 and 4 healds sateen) were used for the investigations. It was stated that the well-known weave parameters of Brierley Fm and Milašius P and P’ cannot be used for the prediction of the tear strength of all kinds of weaves without any limitations. All parameters presented can be used for the strength prediction of a weave when they are divided into two groups – a rib-based group and twill-based group. Prediction of the tear strength for rib-based weaves in the weft has to be carried out using parameter P’weft, where the influence of parameters P1 and P is varied.

Influence of Twist on Selected Properties of Multifilament Yarn

Owing to twisting of filament fiber bundle, the structure and consequently various parameters and properties of a fiber bundle are changed. The aim of the work is to verify the effect of multifilament yarn twist (or twist coefficient) on selected mechanical properties such as multifilament tenacity, breaking elongation, and coefficient of fiber stress utilization in the yarn. Furthermore, the influence of twist on structural parameters such as the angle of peripheral fibers, the packing density, and the substance cross-sectional area of fiber bundle is observed. Two multifilament yarns with different filament cross-section shape and material were used for the experiment. Experimentally obtained data was compared with the known model dependencies derived decades ago based on the helical model. It can be stated that multifilament yarn retraction can be predicted based on the angle of peripheral fibers using the Braschler’s model. The coefficient of fiber stress utilization in the multifilament yarn determined experimentally corresponds with a theoretical curve, constructed according to Gégauff and Neckář, in the area of Koechlin’s twist coefficient α > 54 ktex1/2 m−1. Results as well as possible causes of deviations of experimental data from the theoretical one are discussed in this work.