Band 9, Heft 4

Basing on a detailed kinematics scheme of the R1 Rieter rotor spinning machine, calculation of spectral characteristics of yarn made on the spinning machine was done. The calculations served to create a computer programme facilitating the qualitative evaluation of the spinning process on the R1 spinning machine. It also allows a rapid localising of mechanical damages and technological errors in the machine. The calculations make it possible to detect the sources of periodical faults and damages of yarn which follow from: the noncentred work of elements of the spinning machine or from their being damaged, from damaged pulleys, gear wheels, driving belts, from dirt or damages of the elements driving the roller etc.

Down to the present day there are no sufficient techniques for a small intestine replacement, mostly because of the high standards for such implants. An indication for the need of novel operation techniques is the small patient survival rate of just 80 % for isolated small intestine transplantation and 62 % for combined liver-small intestine transplantation. The five year survival rates of the patients are merely 42 %. In order to overcome these limitations the authors are developing a partly resorbable textile-foam-composite for small intestine replacement The novel implant consists of a non resorbable textile PVDF mesh which is foamed with a micro porous, resorbable, and drug loaded polymer. The resorbable polymer serves on the one hand as initial sealing, therefore no intestine substance and bacteria can leak out into surrounding tissue, on the other hand it needs to be micro porous in order to ensure cell ingrowth. For the macro porous textile mesh warp knitting technology is used. The warp knitted tubular structure remains inside the body as a long term implant and provides mechanical support to ingrowing cells. In order to evaluate biomechanical properties of the warp knitted tubular PVDF meshes to compare them to the mechanical characteristics of small intestine tissue, tensile tests were conducted. Results of tensile tests on warp knitted structures with three different loop densities of 8, 12, and 16 loops per cm were compared to tensile tests on native small intestine tissue probes. The recorded curves of small intestine and warp knitted structures showed similar characteristics. The two characteristic Young Modules as well as the curve progression of the warp knitted structure with 12 loops per cm showed good accordance to the values of the native small intestine. Morphological analysis of the textile structures by digital image processing showed adequate pore size and porosity of the textile mesh.

The paper shows the new method of measurement of yarn length in loop which was developed regarding computer analysis of knitted fabrics pictures on the base of real axis loom path described by co-ordinates in coordinate system XYZ. The measurements of the three-dimensional yarn length in loop were realized in specially developed computer program "The three-dimensional analysis of the loop's picture" that also gives the possibilities of graphic presentation of real shape indicated axis loom path in rectangular coordinate system XY, XZ, YZ. There is shown the characteristic of developed research place that enables the realization of measurements in compute program in 3D system on the base of registered knitted fabrics pictures in particular measurement surfaces. It was also indicated that developed method of measurement of three-dimensional yarn length in loop regarding computer analysis of knitted fabrics pictures is characterized by high precision and gives results closer to experimental values than results gets by using theoretical methods.

In spite of some beneficial effects of ultraviolet (UV) radiation on skin, radiation can cause sunburn, skin aging, allergies and even skin cancer. Textiles can provide effective protection against such damage of UV radiation. Unlike cosmetics, using textiles protecting the skin or at least enhancing protection has only recently been researched. The design and modification of fabrics leading to a high protection against UV radiation is a relatively new application. It is very important to consider the kind of textile to be used, most of the garments worn during summer, the time of highest exposition, are light and colourless materials and therefore provide the lowest protection. We report the synthesis and characterization of nanosized zinc oxide particles known to highly absorb UV light. Sol-gel based inorganic-organic hybrid polymers were modified with these particles and were applied to cellulosic cotton (100%) and cotton/polyester (65/35%) fabrics. These modified inorganicorganic hybrids polymers were based on 3-glycidyloxypropyltrimethoxysilane (GPTMS). Complete finishing sol prepared in this work has remarked long stability for further processing. The effectiveness of the novel finishing was determined by UV-Vis spectroscopy and by evaluation of the ultraviolet protection factor (UPF). The influences of the finishing for some general textile properties as e.g. tensile strength, elongation, air permeability, degree of whiteness, wear-resistance, stiffness as well as the durability of the treatments were investigated.

Formaldehyde based low molecular weight precondensates (fixers) are always have very important role in processing of woven fabrics. Two important applications of these chemicals are in fixing of dyes and improvement of crease resistant behavior of fabrics. The synthesis of a series of precondensates by the reaction of formaldehyde with various percent mole ratios of melamine/urea is described which belong to the class of thermosetting resins. The dyed cotton specimens were impregnated with fixers and cured at 150°C for 3 minutes using acetic acid curing catalyst. The rubbing fastness to crocking, color fastness to washing and light fastness is reported and found to be dependent on the fixing efficiency of precondensate to dye. Precondensate based on 50:50% mole ratio of melamine-urea-formaldehyde showed the excellent fixing efficacy. The fastness to light is found to be dependent on the aromatic character of melamine ring which obviously is due to the preferably absorption in the UV region. The fabrics with an intense color and good characteristics were obtained thus presenting a possibility for extension of the applied in practice textile precondensates.