Study on Special Shaped Polyester Fibers and Development of Products

Non-circular profiled fibers are generally synthetic fibers that have a modified cross-section shape, which are created to mimic natural fibers or to obtain special properties. The shape of the cross-section has great influence on the properties of profiled polyester (PET) fibers and their fabrics. The structure and properties of flat-shaped and hexagonal-shaped profiled PET fibers and ordinary PET fibers, as well as the properties of their knit fabrics were characterized. Experimental results showed that air permeability, heat retention, and wrinkle resilience of profiled PET fabrics were better than that of circular a cross-section PET fiber fabric, while the circular cross-section PET fabric was softer than the profiled PET fiber fabrics.

A Simple Method for the Cross-Section Area Determination of Single Profiled Fibers and Its Application

One of the critical prerequisites for accurately measuring the mechanical properties of profiled fibers is the precise determination of their cross-sectional areas (CSAs). In this study, a new method is established for determining a single profiled fibers’ CSA based on the frozen section method and digital photo, pixel-ratio method (FS-DP). FS-DP is used to obtain a transverse section of a fiber, by acquiring an image of the cross section using optical microscopy or scanning electron microscopy, and then calculating the CSA using Photoshop. Using FS-DP, it was found that the shape of a fiber of silk changes little in a range of 50 μm, but varies considerably over a range of 1 m, while the CSA of cocoon silk (900 m) first increases and then decreases. Mechanical property tests showed that the elongation, strength, elastic modulus, and toughness values of the cocoon silk are consistent with those reported previously. Additionally, FS-DP was also used to observe other profiled fibers. The application tests indicated that FS-DP can be used to quickly and accurately obtain the CSA of a single profiled fiber, and that it is suitable for the large-scale determination and analysis of the mechanical properties of profiled fibers.

Structure and Properties of Novel Modified Polyester Fibers

The structure and properties of the fiber affect its processing and wearing performance of the textile product. There are 3 kinds of novel polyester fibers modified by copolymerization. To make good use of these modified polyester fibers and predict their processing and wearing performance, the structure and properties of the fibers were characterized by cross section, crystallinity, moisture regain, tensile test, DSC and TG. Results show that the 2 of the modified fibers are profiled fibers with lower crystallinity and higher moisture regain. The mechanical properties of the modified fibers are worse than that of the ordinary polyester, but much better than cotton fiber. The modified polyester fibers are more thermal sensitive than ordinary polyester fiber. The heat treatment temperature of them in the textile processing should be controlled more carefully than ordinary polyester fibers.

Preparation of Optical Reflective Fiber with Transparent Nylon

Optical reflective fiber has been widely used in protective clothing for road workers because of high-reflective effect which promised a strengthened visibility at night or in poor visibility. In this paper, four fibers with different cross section shape, i.e., round, triangle, rectangle and hollow pentagon, were melting spun from the transparent nylon which was analyzed and characterized previously. The spinning conditions were discussed in detail, and the hetercliteness of profiled fibers were also calculated. Both the reflectivity and brightness testing indicated that all profiled fibers showed the better reflective ability than the round one. Moreover, the mechanical, thermal and crystalline properties of round and triangle fibers after drawing were characterized.

Study on On the Cross-Sectional Shape Change of the Profiled Fiber along the Spinning Path in Melt Spinning

The cross-sectional shape of profiled fibers has made obvious influence on fibers physical properties. The fiber profiled factor is an index used to estimate the deformation degree of profiled fibers. Based on the equations of melt-spinning dynamics and deformation, a numerical simulation program for calculating the fiber profiled factor along the spinning path was developed. A numerical simulation for calculating the fiber profiled factor along the spinning path of trilobal fibers in the PET melt spinning was performed. The simulation result graph of the fiber profiled factor along the spinning path is close to the final average fiber profiled factor measured in the spinning experiment under the same condition.