Textile Research Journal

Seam slippage, which occurs frequently in furniture upholstery fabrics on the parallel sewing line, even though it is undesirable, results in partial or full distortion of fabric appearance. The purpose of this study is to reduce the seam slippage in upholstery chenille fabrics, which are widely used in furniture production.

This is the preliminary study, in which the effects of sewing direction and the number of interlaced chenille yarns over warp yarns on seam slippage were investigated for the first time. Aside from the effects of fiber content, sewing stitch step, weft densities of fabrics, sewing direction according to the weft and warp and the number of interlaced chenille yarns over warp yarns on seam slippage were studied with the use of multifactor experiment. On the basis of these experiments, effects and impact factors of the aforementioned parameters on seam slippage were shown with the use of mathematical models.

A theoretical model for the oblique incidence sound absorption coefficient of thin woven fabrics backed by an air cavity is presented where the fabric is acoustically described by its specific airflow resistance and its surface mass density. The theoretical model is illustrated by an equivalent electrical circuit and validated in the case of normal sound incidence by experimental results obtained from impedance tube measurements on three fabric types. The influence of the surface mass density on the absorption coefficient is discussed and recommendations for practical applications are derived. Further, a simple formula to predict the specific airflow resistance of woven fabrics based on geometrical parameters is deduced. The normal incidence absorption coefficient and geometrical parameters of a set of 24 fabrics with a large range of interyarn porosities and specific airflow resistances were measured and used to validate the proposed geometry-based model to predict the absorption coefficient. Measured and estimated absorption coefficients show excellent agreement, with mean value and standard deviation of the differences of 0.03 ± 0.10. The model is therefore suitable for the design of new fabrics with an intended absorption coefficient.

The amount of research conducted on sound absorption properties of woven fabrics in comparison to nonwoven and spacer textile fabrics is very limited. The main aim of this research is to study acoustical and sound absorption properties of woven fabrics. Normal incident sound absorption coefficient was determined via the impedance tube method. To achieve the objective of the research, general acoustical properties of textiles together with existing standards were thoroughly studied. Samples of woven fabrics having varying structural elements, such as weave type, weft yarn linear density, thickness created by layering of test fabrics, yarn spinning system and depth of air space at the back of samples were tested. Results showed that, for most samples while the maximum value of the sound absorption coefficient occurred at a frequency of 1000 Hz, the minimum value was observed at frequencies of 250 and 2000 Hz. Results showed that, the sound absorption coefficient of woven fabrics is influenced by both density and porosity of fabrics. It was found that, plain fabric absorbed sound wave more than the other weave types. Results also indicated that, for a given weft density, fabrics produced with weft yarn linear density of 24.5 tex has a higher absorption than fabrics woven with weft yarns of other counts. It was found that, finer weft yarn and higher thickness of fabric causes the noise reduction coefficient or NRC of the fabric to be increased. It was established that, fabrics woven using rotor-spun yarns exhibited the highest absorption in comparison to samples woven using ring-spun or compact yarns.

The primary function of military body armour is to provide protection from fragmenting munitions and improvised explosive devices (IEDs). This is usually achieved by the use of multiple layers of woven para-aramid fabric. The resulting body armour is heavy and contributes to the burden on the dismounted soldier. Reduction in body armour mass and hence thermophysiological loading without reducing the level of protection is therefore of interest worldwide. Many manufacturers quilt the fabric component of body armour which reportedly improves fragment protective performance, however, the topic does not appear to have been explored thoroughly. In this work a preliminary study on the effect of quilting on the fragment protective performance of a commercially available woven para-aramid fabric is reported. The fragment protective performance of specimens varying in construction (1, 2, 3 and 5 layers) with three quilting regimes (no quilting, diamond quilting, square quilting) is presented and analysed.

This study was undertaken to establish a relationship between aerobic biodegradability and molecular structure of acrylate copolymers for the design and production of the copolymers with good biodegradability for warp sizing. Biological oxygen demand for five days (BOD₅) and chemical oxygen demand (COD) of the copolymers were assessed and the BOD₅/COD ratio was used to evaluate their biodegradability. The influence of the number of carbon atoms in the alkyl group of alkyl ester chain on the biodegradability was studied and the effect of α-methyl group was evaluated. Moreover, the impact of molar content of acrylate units on the biodegradability was also studied. It was found that the decrease in the number of carbon atoms in the alkyl group of alkyl ester chains and the reduction in molar content of acrylate units improved the biodegradability of acrylate copolymers. Biodegradation of acrylate copolymers proved to be difficult if an α-methyl group was present in the acrylate units. To produce acrylate copolymers that are able to biodegrade more easily, a suitable amount of acrylate monomers with shorter alkyl side-chains and without an α-methyl group should be applied to monomer formulation for the copolymerization with hydrophilic monomers. The preferred molar content of the acrylate monomers should be in a range of 60% to 70%. The acrylate copolymers thus prepared were biodegradable and aerobic biodegradation was capable of converting macromolecules to lower molecular weight end-products.

The role of strain level in the assessment of wrinkling performance of 100% cotton fabric treated with various in-wear wrinkle-resistant (IWWR) additives was investigated. Two additives, a cross-linking agent and a fabric lubricant were both separately and in combination applied to cotton fabric samples. In this investigation multiple laboratory tests were used, including fabric bending hysteresis and stress relaxation under medium to high curvatures, fabric shear, controlled laboratory fabric wrinkling (wrinkle tester) as well as crease recovery angle measurements. The results were analyzed, with reference to the viscoelastic and frictional model of fabric wrinkling, in order to evaluate the IWWR performance of the treated and untreated fabric samples objectively and quantitatively. The correlation between these results and the subjective evaluation of wrinkle recovery performance of shirts in an in-wear panel test was evaluated.

Green tea has recently been reported to be a good dispersant of single-walled carbon nanotubes (SWCNTs) in aqueous media. In the current work, green tea extract powder was examined for dispersion of SWCNTs in organic solvents. Dimethyl sulfoxide (DMSO) was found to be a good solvent of green tea extract for dispersing SWCNTs. A combination of green tea (dispersant)/DMSO (solvent)/polyvinyl alcohol (PVA) (nanotube wrap) was obtained that resulted in the dispersion of SWCNTs almost to individual nanotubes or to very thin nanotube bundles. The reinforcing ability of highly dispersed SWCNTs was explored in a PVA matrix producing PVA-SWCNT gel-spun fibers. Extraordinary reinforcing effects on the tensile and dynamic mechanical properties of the composites were observed by incorporating a minute amount of SWCNTs (∼1 wt% to PVA). The analysis revealed effective stress transfer through the PVA crystalline interfaces surrounding the nanotubes.

Dynamic permeability is relevant to textile applications subjected to fluid/gas flow under high pressure, such as automotive airbags, wearable airbags and parachute fabrics. Dynamic permeability can be determined when a porous medium is tested under transient pressure conditions. This paper utilizes a reliable approach to measure and characterize dynamic permeability for woven fabrics. The experimental principle is based on the ideal gas law and the non-linear Forchheimer equation. Compared with static permeability measured under a constant low pressure, the dynamic permeability is an intrinsic property determined by change of fabric geometry and structure due to a high-pressure load. The pressure-induced deformation is identified, including effects on fiber and yarn arrangement, yarn porosity and fabric thickness. The level of deformation is a function of the number of fabric layers and initial pressure drop. The experimental results show that the dynamic permeability is higher than the static permeability for loose fabric, while it is lower for tight fabrics. For tight fabric, more fabric layers and a lower initial pressure can reduce the difference between the static and the dynamic permeability. Analytical models are used to explain and predict both static and dynamic permeability.

In this paper we describe the manufacturing and testing of an intelligent carbon fibre composite based on 3D-woven reinforcement. Piezoresistive fibrous sensors developed and optimized previously have been inserted into the carbon fibre reinforcement in the weft direction on a modified loom. These sensors were integrated at the top and bottom faces. Afterwards the reinforcement with embedded sensors was impregnated in epoxy resin using VARTM technology. The composite specimens thus obtained were tested for bending using the three-point bending test method. The results obtained show that the sensors allow simultaneous mapping of compression and traction at the top and bottom of the reinforcement when it undergoes bending. This is due to the fact that, unlike traditional strain gages, our sensors become integral part of the reinforcement and follow the tow architecture as dictated by the weaving process and interlacement pattern. Moreover, these sensors are compatible with the weaving process as they are flexible and sensitive enough to follow the deformation pattern of the reinforcement. Such sensors can be inserted inside various types of reinforcements during weaving in both warp and weft directions. Their location can be strategically chosen so as to form a network of sensors inside the reinforcement capable of following the deformation patterns of the reinforcement and mapping its stress–strain history.

In this paper, the low velocity impact characteristics and impact damage of sandwich composites, produced at four different core thicknesses from 3-dimensional (3D) integrated sandwich fabrics, with and without foam filling, have been examined. The 3D sandwich fabrics have been produced using the same yarn and weaving densities. Thus, the impact characteristics are only affected by the core thickness and whether foam filling is used or not. Low velocity impact tests have been conducted at 32 and 48 J energy levels. The impact behavior has been determined as a function of the peak load, the energy to peak load, the time to peak load and the absorbed energy. The impact damage and the change in the compressive strength after impact have been analyzed. The findings obtained indicate that core-skin delamination on 3D sandwich composites has been fully prevented. Impact tests carried out on integrated 3D sandwich structures have shown that impact damage is limited to the vicinity of the point of impact and does not affect the integrity of the structure. This indicates that such damage can be easily repaired and the service life of the product can be sustained.