1,721,059 research outputs found
Development of an individual warp beam tension control system for warp assembling machines in direct warp preparation
Get PDFWarp preparation is a process prior to weaving that brings all the ends side by side and then winding them on a warp beam with the same tension and length at a predetermined width, density and length. Modern warp preparation machines employ feedback control systems controlling total or individual warp tension. Older warping machines in industry mostly do not have a precise feedback tension control systems and do not match with the quality requirements of today's market expectations. This paper presents a research in which an individual section beam warp tension control system is explained for converting older beam-assembling machines to a new technology in a direct warping process. The total warp tension of each section warp beam was measured and breaking torque of the magnetic powder brake was adjusted when a deviation occured from the set tension value. It was shown that average loom efficiency increased by 5.65% despite an increase in average loom speed from 663 to 733 rpm in an air jet loom factory. The fabric fault ratio decreased from 3.45% to 1.04% per 100 m of fabric and warp waste decreased from 0.5% to below 0.2% with the new individual section warp beam tension control system adapted to an older version of the assembling machine having total tension control and section warp beam pneumatic brake system
A comparative study on the acoustic absorption properties of green synthesis cellulose nano enset fibers
No full textNatural fibers are becoming a valid alternative to most commercially used synthetic fibers in sound absorbing materials. In recent years, natural fibers have been considered as valid raw materials for producing ecofriendly sound absorbing materials at low cost. This paper presents a new study on enset nanofiber sound absorbing material which was prepared by enzyme treatment and mechanical hammering of the surface of enset woven fabric. Enset nano fiber (ENF) was fabricated by defibrillation of underutilized abundant byproduct fibers from the surface of enset woven fabrics into micro and nano-scale fibers by alpha-amylase enzyme treatment and then mechanical hammering. The purpose of this approach is that the product will be economic and environmentally friendly and also consumption of eco-friendly products is a serious concern of researchers and policymakers. The study was conducted by using impedance tube method and the sound absorption properties of enset micro and nanofibers in a frequency range of 1000 to 6000 Hz were studied by changing the diameter, thickness and percentage of enzyme concentration during fiber treatments. Parameters for enset nanofibers were: number of board layers (single, double, triple and fourth-layer having sample thickness of 10-13 mm), fine fiber size (micro and nano meter), and fine fiber treatments content (10, 15 and 20% w/v), pressing time (10 min), board density (0.95 g/cm3), press pressure (40 kg/m2) and press temperature (180 degrees C) were held constant. The experimental results revealed that at the same frequency (4500 Hz), the sound absorption coefficient value was improved by 176 and 213% when neat enset fabric was treated and hammered with 10 and 20 w/v % concentration of amylase enzymatic respectively. The maximum sound absorption of neat enset fabric and enset nanofibers was recorded as 0.47 and 0.99 around 5351 Hz respectively. These results indicate that the acoustic property of enset fiber was improved by 47% when neat enset fiber was converted into green enset nanofiber forms by enzyme treatment and mechanical hammering. The experimental results shown that green synthesis of fine fibers from the surface of woven fabric improved the maximum acoustic peak values by 43% (microscale) and 59% (nanofiber) compared with macroscale enset fibers. These simple and cost effective green cellulosic enset nanofiber formations would have a promising result for small scale acoustic enterprises
Investigation of ballistic properties of woven-unidirectional hybrid panels according to energy absorption capabilities
No full textThis paper presents an investigation regarding the ballistic performance of hybrid panels formed by combining para-aramid woven fabrics and unidirectional fabrics. For this purpose, hybrid panels are formed at different structure and fabric ply numbers by combining Twaron CT 710 type woven and K-Flex unidirectional fabrics. The hybrid panels formed this way are subjected to ballistic tests according to NIJ standarts. Ballistic performance of test samples are determined by measuring trauma depth and diameter. The energy absorbed by fabric layers and the energy transmitted to the back of fabric layers are determined from trauma depth and diameter values using a different approach. It is shown that in hybrid panels, around 4.48% improvement is obtained in trauma depth in hybrid panels compared to panels formed by 100% woven fabrics and 3% improvement is obtained in trauma diameter in hybrid panels compared to panels formed by 100% unidirectional fabric panels. As far as the energy transmitted to the back side of the panels is concerned, an improvement of 13.9% is gained with hybrid panels compared to 100% unidirectional fabric panels. It is also found that an improvement of 8.48% in energy absorbed per unit weight is obtained with hybrid panels compared to the panels formed by using 100% woven fabrics.SAMPE Baltimore/Washington Chapte
Dynamic analysis of Cam driven Sley mechanism
No full textToday looms work at high speeds. For instance, speed reaches greater than 1000 cycles/minute in air jet looms. This situation requires some precautions like mass balancing in order to prevent vibrations In this study, by making dynamic analysis on a loom which have a cam driven sley mechanism, the forces acting on the mechanism and the bearing forces that cause vibrations are provided. And they were presented as graphics with respect to the main cam shaft rotation angle.AATCCINDATAPPIThe Fiber Societ
ANALYSIS OF HARDNESS VARIATIONS IN RADIAL AND LONGITUDINAL DIRECTION OF BOBBINS IN STEP PRECISION WINDING
No full textStep precision winding is a widely used bobbin winding method in industry, especially for dyeing bobbins. It is important to adjust winding parameters in an optimum way to obtain optimum hardness variation and best dyeing performance. Main winding parameters are winding pressure, crossing angle and yarn tension. This paper presents a research investigating the effect of main winding parameters on hardness distribution in radial and longitudinal directions of bobbins wound with step precision winding. Bobbins are produced from Ne 30/1 and Ne 10/1 cotton yarns. Bobbin hardness is measured by a new instrument called UNITORQ, which enables the measurement of relative bobbin hardness in radial and longitudinal directions with small increments of distance. It is found that crossing angle affects mainly longitudinal hardness variation while radial hardness variation is determined and affected in a large variation interval by winding tension. Winding pressure is seen to have no significant effect on winding hardness distribution in both radial and longitudinal directions but it determines bobbin hardness level together with winding tension and crossing angle
An investigation into ballistic performance and energy absorption capabilities of woven aramid fabrics
No full textThis paper presents an investigation regarding the ballistic performance of protection panels of different fabric ply numbers used in body armours. Twaron CT 710 type fabric layers of differing numbers are joined by using three stitch types to form the panels and then the panels are subjected to ballistic tests according to NIJ standards. Ballistic performance of the panels is determined by measuring trauma depth and trauma diameter. The energy absorbed by the fabric layers and the energy transmitted to the back of the fabric layers are determined from the trauma depth and trauma diameter values using a different approach. It is shown that the fabric ply number and stitching type have significant effects on ballistic properties and the effect of conditioning is limited
One-step preparation of woven fabric-reinforced hydrogel composite
No full textCotton-woven fabric-reinforced polyvinyl alcohol-based hydrogel composite was produced by constructing cotton as warp and polyvinyl alcohol/cotton hybrid and polyvinyl alcohol yarns as weft yarns in the fabric structure. As-prepared polyvinyl alcohol/cotton fabrics were treated with different concentrations of aqueous borax and glutaraldehyde crosslinking solutions. Polyvinyl alcohol molecules were transformed to crosslinked gel structure after the treatments. Since cotton yarns kept their yarn structure in the fabrics, woven fabric-reinforced hydrogel composites were obtained. Chemical analysis to investigate crosslinking was conducted by attenuated total reflection-Fourier transform infrared spectroscopy spectra analysis, and the results revealed that a proper crosslinking of polyvinyl alcohol molecules in polyvinyl alcohol yarns occurred by using both borax and glutaraldehyde as crosslinkers. Thermal stabilities of the samples were observed via thermogravimetric analysis measurements. Even though borax crosslinking increased the thermal stability, glutaraldehyde crosslinking did not have a significant effect on the thermal stability of hydrogel composite. Crystalline microstructural analysis was carried out with X-ray diffraction measurement. Tensile properties of the samples by focusing on the crosslinker ratio and water contents in the hydrogel composites were performed. The results revealed that tensile properties of hydrogel composite tremendously increased with fabric reinforcement. Also, breaking force gradually increased when the hydrogel composite structure released the water from its structure at both borax and glutaraldehyde samples. Since the produced fabric-reinforced hydrogel composites have high strength, they are promising candidates as hygroscopic materials for planting and erosion control at inclined terrains
Yarn-reinforced hydrogel composite produced from woven fabrics by simultaneous dissolution and cross-linking
No full textPolyvinyl alcohol (PVA)/cotton (Co) woven fabrics were produced by constructing Co as warp yarns and PVA as weft yarns in the fabric structure. As-prepared PVA/Co fabrics were treated with borax/water solution. Because of the simultaneous dissolution and gelation of PVA yarn in the fabric and transformation of PVA molecules into cross-linked gel structures, gel penetrated among the yarns in the matrix form and hence Co yarn-reinforced composite hydrogels were obtained. The retention time of water by composite hydrogels was first increased and then decreased by increasing borax concentration in the cross-linker solution. With yarn reinforcing, the tensile strength of hydrogel structure significantly increased. Mechanical properties of hydrogel composites were very variable depending on water content in the structure and tensile strength tremendously increased when water evaporated from the structure. Thermal and chemical characterizations of yarn-reinforced hydrogel composites were conducted in addition to swelling and mechanical analysis to investigate the performance of the hydrogel composites
An investigation into the parameters of terry fabrics regarding the production
No full textThis paper aims at introducing an approach for determining the constructional parameters of a terry fabric for weaving. Experimental work has been conducted with 72 different terry fabric samples designed and produced for this purpose. The weaving contractions of the terry fabrics are found to change between 1.5 -2.0% in both warp and weft directions. Contractions after washing are between 5.5% and 11.5 depending on the fabric construction. The weight per square metre, shearing waste and weft, ground warp and pile warp yarn ratios have been measured, and the effects of the constructional parameters of terry fabrics on these values are discussed. The shearing waste is found to amount to between 9.4% and 17.4% for different fabric constructions. Mathematical expressions are derived for the calculation of weight per square metre in terms of terry fabric constructional parameters, and for the required weft density and pile length satisfying a desired weight per square metre. A close agreement is found between the calculated and measured weight per square metre. A close match is also found between the measured pile lengths and the distance between the short and full beat-up points. It is concluded that the use of mathematical expressions, with the support of some experimental data such as the contractions, minimises or in some cases even eliminates the need for trial production
Regenerated cellulose woven fabric reinforced hydrogel composite
No full textThis study evaluates the effects of different aqueous borax solutions on the morphology, mechanical, thermal and chemical properties of regenerated cellulose fiber woven fabric reinforced hydrogel composites. The fabric reinforced hydrogel composites were fabricated with PVA/viscose ring, PVA/viscose open-end (viscose OE), PVA/viscose continuous filament (viscose CF) blended woven fabrics. Mechanical tests results showed that regenerated cellulose fiber woven fabric reinforced hydrogel composites made from PVA/viscose CF (380 N) exhibited better mechanical performance than its viscose ring (258 N) and viscose OE (318 N) counterparts. Another significant result, evaluated using statistical package for social sciences (SPSS) data analysis showed that there was a high level positive and meaningful relationship between borax-water concentration and breaking force at the breaking points of regenerated cellulose woven fabric reinforced hydrogel composites in the warp direction. The results have suggested that the regenerated cellulose fabric reinforced hydrogel composites with enhanced mechanical properties could be used as agricultural water retention materials and in geotextiles applications
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