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Around the world, people living close to polluting industries have different perceptions of the risks of toxic exposure, ranging from anger to acceptance to denial. We draw attention to a case with relatively high levels of social trust, but also relatively high levels of risk perception: the communities living adjacent to the Fawley (UK) oil refinery and petrochemical complex, a site that has been operated by Esso since the early 1950s. Our findings are based on a novel comparative analysis of two qualitative studies of local risk perceptions in Fawley conducted more than two decades apart in 1997 and 2019, incorporating focus group and individual interviews with residents, alongside documentary analysis and stakeholder interviews. Perceptions of risk and trust in the local polluting industry have fluctuated over the years, with unease never far from the surface as industrial employment has slowly contracted. Yet overall, the picture in 2019 was not too dissimilar from that in 1997: while community–industry relations were strained amidst periodic risk incidents and a sense of decline, a cautious sense of trust in the polluting enterprise had endured, based on a delicate balance of heritage, risk, and recognition. We draw attention to the residents’ careful reckoning with risks over time and the tenacity of social trust as an act of negotiation that took risk into account but also included other important factors such as recognition and reciprocity. Local risk perceptions in Fawley are closely bound up with the residents’ shared industrial heritage and enduring perceptions of Esso as a ‘good neighbour’. Our longitudinal analysis allowed us to reflect on changes over time in Fawley, providing greater temporal depth to the risk perception literature.

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.

The events that followed the revolution of 25 January 2011 demonstrated the tenacity and resilience of gendered dissent and its centrality to collective action and civil disobedience, thus enriching the transnational feminist archive with the experiences and praxis of gendered revolutionary action. Paying particular attention to women’s activism during the uprisings in Egypt, this article focuses on the broader themes of gendered political resistance and the intersections of gender ideology, state policing, Islamism and militarism with protest and collective action. The aim is to take count of the challenges and gains of gendered resistance and women’s political participation during times of political upheaval.

This paper aims to identify the creep mechanisms of high tenacity (HT) polyester industrial fiber under different loads. In-situ synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) tests were conducted on a 1000 D HT fiber during the creep and creep recovery process with a low load (15 N) and a medium load (50 N) as well as creep rupture process with a high load (60 N). The measured creep strain-time curves comprised tensile zone (I), creep deformation zone (II) and creep recovery/rupture zone (III). The SAXS indicated that the macroscopic initial creep strain in zone I and creep deformations in zone II were attributed to conformation transition from gauche to trans in amorphous region, increasing the amorphous orientation and long period. Irreversible portion of conformation changes accounts for the small unrecoverable plastic creep strain after removing 15 N load in zone III. The initial creep strain in zone I and creep deformations in zone II of the 50 N creep process were bigger than the microscopic long period strain, because amorphous layers had conformational transformation and microfibril slippage which also produced a higher unrecoverable plastic creep strain in zone III. The long period increased significantly at the beginning of rupture zone with 60 N due to fragmentation of amorphous tie molecular. The disappearance of lamellar peaks at the end of rupture zone implied destruction of periodic lamellar structures, for the entire breakage of amorphous chains. The WAXS suggested that the crystal structure was stable under the creep loads.

Ultra-high molecular weight polyethylene fibre is popularly used in military for ballistic protection owing to its low density but high modulus and high tenacity. However, the inter-yarn friction in the corresponding ballistic fabric is too low and thus the yarns in the fabric are easily pulled out, in which lowers down the ballistic performance. This paper aims to improve the inter-yarn friction in the fabric by sol-gel method using TiO2/ZnO hydro-sols and investigate the ballistic performance of fabric treated. The results from the coefficient of friction test have showed that the inter-yarn friction treated with TiO2/ZnO hydro-sol can be increased 40%. Moreover, tensile test indicates that the tenacities of yarns after different treatments are increased whereas the strains and moduli of the yarns almost kept unaffected. Through ballistic performance test, the treated fabric displays higher ballistic energy absorption compared with the original one, indicating that higher inter-yarn friction is beneficial to fabric against ballistic impact.

In this research work, the authors have investigated the influence of fibre orientation on thickness and tenacity of needle-punched nonwoven fabrics by using three-factor three-level Box–Behnken Design. Three carding parameters such as feeder speed, cylinder speed and doffer speed, which are primarily responsible for fibre orientation, were considered as three factors with three different levels. Fibre orientation was evaluated in terms of anisotropy by using tracer fibre technique. Anisotropy was measured in both un-punched and punched fibrous structure. Tenacity was measured in both machine and cross directions. It was found that the tenacity in the cross direction and thickness decreases but the tenacity in the machine direction increases with the increase of anisotropy as well as fibre orientation.

There has been great interest in assessing yarn tenacity directly from available cotton fiber property data acquired by various means, including high-volume instrumentation (HVI). The HVI test is a primary and routine measurement providing fiber properties to cotton researchers. Knowledge about yarn tenacity within a cotton cultivar or between cultivars could be useful with regard to understanding the selection of cotton cultivars. This study examined the effect of cotton growth location, crop year, and cultivar on three relationships (fiber strength versus fiber micronaire, yarn tenacity versus fiber micronaire, and fiber strength versus yarn tenacity), and found great variations in the Pearson correlation and the gradients of respective regression lines. Instead of developing linear regression models from HVI fiber properties to predict yarn tenacity, this study applied a simple ratio method (i.e. normalized fiber strength or yarn tenacity against five HVI fiber properties) to relate fiber strength with yarn tenacity. The short fiber index was found to have a greater effect on the correlation between modified yarn tenacity and modified fiber strength than micronaire, yellowness, upper-half mean length, or uniformity index. This result implied the feasibility of utilizing HVI fiber short fiber index and strength data, as a semiquantitative and fast approach, to compare yarn tenacity performance within a cotton cultivar or between cultivars.

Based on the mechanical analysis of the forming process and tensile fracture of jet vortex spun yarn, this article establishes the theoretical calculating system of the breaking tenacity of jet vor...

There has been a major shift of investment in extractive industry to the global South in recent decades. The repercussions are evident in the rise of protests from local communities against mining, but these face multinational companies, state and financial institutions operating as a coalition of the powerful. This article investigates how an apparently powerless community in Bangladesh succeeded in harnessing long and strong connections with transnational organisations to halt a proposed open-cast mine. Local protestors first connected with national environmental rights groups and then with diverse transnational partners. I examine how the Phulbari resistance, as it is known, succeeded by managing connections using reciprocal tenacity and obligation towards the environment. A strong and independent national-level environmental justice mediator (National Committee) kept the coalition close to its local core. The article presents an empirical case on the rise of the global South in transnational environmental politics.

The self-reinforced composites based on poly(ethylene terephthalate) (PET) are relatively new materials, competitive to composites based on polymers from the group of polyolefins. The use of PET as a base material should be another step forward for this technology, taking into account the properties, price, and the recycling possibility of proposed composites. In this research work, the main subject was to assess the impact of processing conditions on the final properties of the PET self-reinforced composites (srPET). The examined samples were prepared by hot-compaction technique under variable thermal conditions. The input material was composed of PET resin and low-melting copolymer (LPET). The high tenacity PET fibers were used as reinforcement for PET copolymer matrix. Initially both materials were in the form of continuous fiber; they were woven into a hybrid yarn wherein the proportion of PET and LPET fibers was 50/50. The properties of this hybrid yarn were investigated by differential scanning calorimetry (DSC) analysis, where the hot-compaction process conditions were simulated. Composite samples were investigated using the dynamic mechanical analysis (DMA) and static tension tests. The structure of the composite was observed using the optical microscope. The obtained mechanical properties of such a composite are not comparable to commercially made composite sheets, in which overall properties are mostly higher.

Ramie ( Boehmeria nivea L.), a perennial herb, is an important bast fiber plant. Its fiber with the advantages of attractive luster, high tenacity, enhanced strength, and good microbial resistivity is well known as the queen of natural fibers. The abundant cellulose fibers in ramie raw materials are stuck tightly by gums consisting of pectic substances, hemicelluloses, and little lignin. The gum should remove from the ramie raw material through degumming process to separate fibers, unveil unique fiber properties, and improve fiber-spinning ability to fulfill textile requirements. Low degumming efficiency and high environmental pollution are the major problems hindering the utilization of ramie fibers. Ramie degumming involves the degradation of pectin and hemicelluloses, which requires chemical, physical, biological treatment, or a combination of several treatments. No stereotyped parameters of the given degumming method have been yet established for the extraction of textile-grade ramie fibers. This review evaluated integrated methodology involving chemical, physical, biological and biochemical methods to degum raw ramie and obtain textile-grade refined fibers.

Ioncell-F, a recently developed process for the production of man-made cellulosic fibers from ionic liquid solutions by dry-jet wet spinning, is presented as an alternative to the viscose and N-methylmorpholine N-oxide (NMMO)-based Lyocell processes. The ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate was identified as excellent cellulose solvent allowing for a rapid dissolution at moderate temperatures and subsequent shaping into continuous filaments. The highly oriented cellulose fibers obtained upon coagulation in cold water exhibited superior tenacity, exceeding that of commercial viscose and NMMO-based Lyocell (Tencel®) fibers. The respective staple fibers, which have been converted into two-ply yarn by ring spinning technology, presented very high tenacity. Furthermore, the Ioncell yarn showed very good behavior during the knitting and weaving processes, reflecting the quality of the produced yarn. The successfully knitted and woven garments from the Ioncell yarn demonstrate the suitability of this particular ionic liquid for the production of man-made cellulosic fibers and thus give a promising outlook for the future of the Ioncell-F process.

This study uses metallic wires, stainless steel (SS) wires, and copper (Cu) wires as the core and 75 denier polyester (PET) fibers as the wrap material to form the metal/PET wrapped yarns. The optimal SS/PET and Cu/PET wrapped yarns are then made into different woven fabrics. The test results of the metallic wrapped yarns show that the optimal tenacity occurs with the wrapping count being 12 turns/cm, while the metal/PET woven fabrics have a low surface resistivity due to the conductive metal/PET wrapped yarns along the weft direction. An increasing number of laminating layers increases the electromagnetic shielding effectiveness (EMSE) while decreasing the air permeability of the woven fabrics. The laminating angle is also proportional to the EMSE of the woven fabrics. In sum, the combination of metal wires and PET fibers provides the resulting woven fabrics with good EMSE.

This study considers how employees’ tenacity might enhance their propensity to engage in knowledge exchange with organizational peers, as well as how the positive tenacity–knowledge exchange relationship is invigorated by two types of role conflict: within-work and between work and family. Using data from a large Mexican organization in the logistics sector, this study shows that tenacity increases knowledge exchange, and this effect is stronger at higher levels of within-work and work–family role conflict. The invigorating role of within-work role conflict is particularly salient when work–family role conflict is high. These findings inform organizations that the application of personal energy to knowledge-enhancing activities is particularly useful when employees encounter severe workplace adversity because of conflicting role demands.

The effect of fiber cement interactions and its influence on flexural and tensile properties of cementitious composites are well known. In this research, acrylic fibers with different cross sectional and longitudinal shapes and different tensile strengths were selected as reinforcement of the specific fine aggregates concrete. Three point bending test, pullout test, and scanning electron microscopy were used to investigate flexural and pullout behavior of the composites. It was found that flexural toughness and pullout strength were increased 20% and 34%, respectively, by application of kidney shaped acrylic fibers in comparison to dog bone shaped acrylic fibers. It was also found that the flexural and pullout strength of composites containing non-crimped fibers are 33% and 26.5% higher than specimens with crimped fibers, respectively. Results showed that the flexural toughness and pullout strength of high tenacity fiber is 75% and 131% higher than regular fiber as well, respectively. The effect of fine aggregates on the adhesion of fibers to cement matrix was evaluated.

A fundamental understanding of the relationship between cotton fiber strength (or tenacity)/elongation and structure is important to help cotton breeders modify varieties for enhanced end-use qualities. In this study, the Stelometer instrument was used to measure the bundle fiber tenacity and elongation properties of different cotton fibers. This instrument is the traditional fiber strength reference method and could be still preferred as a screening tool owing to its significant low cost and portability. Fiber crystallinity ( CIIR) and maturity ( MIR) were characterized by the previously proposed attenuated total reflection (ATR)-based Fourier transform infrared protocol that has microsampling capability and is suitable for the tiny Stelometer breakage specimens (2 ∼ 5 mg), which cannot be readily analyzed by a conventional X-ray diffraction pattern. Relative to the distinctive increase in fiber tenacity with either CIIR or MIR for Pima fibers ( Gossypium barbadense), there was an unclear trend between the two for Upland fibers ( G. hirsutum). Although fiber elongation increases with elevated CIIR and MIR for Pima fibers, it generally decreases as CIIR and MIR increase for Upland fibers. Furthermore, small sets of Upland fibers with known varieties and growth areas were examined, and their responses to both CIIR and MIR are discussed briefly.

There are technological limitations in the processing of smooth, slippery and rather flat multifilament viscose rayon yarn. The present work describes a shorter route for viscose rayon modification through mechanical crimp texturizing. Texturizing was performed with different pre-twists and optimized texturizing twist. This work describes a shorter and cost effective route for viscose rayon modification through mechanical crimp texturizing. The prepared texturized viscose rayon yarn has achieved the desirable structural characteristics of spun yarn as depicted in SEM micrographs. The textured yarn has retained an almost identical fineness with the parent yarn. Unlike air jet texturizing, mechanical crimp texturizing has benefits in terms of retro-processing of costlier viscose rayon yarn. Although it was textured, it has not shown any significant drop in tenacity and, apart from that, shows enhanced the elongation property compared to the parent yarn.

This article presents the strength, diameter, elongation and tenacity variations of banana pseudo-stem fibres extracted from five common Sri Lankan cultivars. The banana plants that were selected represent the dry and wet climatic zones of Sri Lanka. Mixtures of all layers of stem from the selected cultivars were subjected to three different extraction methods. Decortication technique was used for mechanical extraction, sodium hydroxide was used for chemical extraction and pectinase enzyme was used for biological extraction. The mechanical extraction method resulted in coarser fibres, chemical extraction resulted in a 30% reduction in the fibre diameter, while the biologically extracted fibre presented a 40% increase in fibre strength compared with the mechanically extracted fibres. Scanning electron microscopy analysis revealed the presence of damaged fibrils in mechanical extraction and removal of binder material in the chemical and biological extraction methods. Furthermore, Fourier transform infrared spectroscopy analysis proved the removal of lignin in chemical and biological extraction. Different cultivars presented different behaviours in extensibility, which is common in natural fibres.

The relative rate of degradation of poly(ethylene terephthalate) geotextiles in various monovalent alkali hydroxides was studied in both aqueous and alcoholic systems. In an aqueous system, the reaction of all three alkalis on poly(ethylene terephthalate) geotextiles is restricted to the surface since tenacity loss was insignificant and no surface cracks was noticed, whereas in an alcoholic system, significant loss in tenacity occurred due to the formation of surface crack. Furthermore, the relative rate of reactivity of metal hydroxides in aqueous and alkaline media was temperature dependent. However, in equimolar concentration, at 80℃, the relative rate in an aqueous system is of the following order: LiOH > NaOH > KOH in the ratio of 1.65:1.1:1.0. Above 80℃, the reaction is reversed, as aqueous KOH reacts faster than aqueous NaOH. Two different activation energies were found for aqueous KOH at a threshold temperature of 80℃. Furthermore, in heterogeneous systems using dimethyl terephthalate, aqueous KOH was slightly faster than aqueous NaOH in the temperature range of 70–80℃. In an alcoholic system, KOH is almost 1.5 times faster than NaOH at 20℃ and at 60℃.

A crystal silica was intermingled with an elastic ethylene-vinyl acetate polymer to fabricate an encapsulant and improve its thermal conductivity. The encapsulant showed not only an improved thermal conductivity and adhesiveness but also good thermal stability and tenacity. Its thermal conductivity with various sizes, dosage, and surface properties of silica (SiO2) was investigated using laser scattering method. The tenacity and adhesion properties were evaluated using dynamic viscoelasticity and peel strength, respectively. The integrated properties of the encapsulant were obtained while SiO2 reached to 80 wt portions in composite. Thermal conductivity of the composite was less dependent on the surface properties of SiO2.

In the present work, chitosan was applied on to the braided silk sutures at three different concentrations and the effects of chitosan coating on the characteristics of braided silk suture were explored. The frictional characteristics of BSS were studied by determining the dynamic coefficient of friction at various normal loads and sliding speeds. At higher normal loads and sliding speeds, both the chitosan coated and uncoated braided silk suture showed lower value of dynamic coefficient of friction. Furthermore, for all the tested normal loads and sliding speeds the chitosan coated braided silk suture showed lower value of dynamic coefficient of friction than the untreated BSS. Instron tensile tester was used to measure the tenacity and knot strength. The result showed that the tenacity and knot strength of braided silk suture increases with the increase in chitosan concentration. The scanning electron microscopy reveals the uniform deposition of chitosan on to the surface of the braided silk suture. The antimicrobial activity of chitosan coated braided silk suture against Escherichia coli and Staphylococcus aureus were evaluated using agar diffusion method (SN 195920) and shake flask method (AATCC 100). The braided silk suture treated with higher chitosan concentration exhibits excellent antimicrobial activity against both the bacteria.

This study was performed in order to investigate the effects of tandem and conventional vacuum steaming on the physical properties of 100% cotton and 100% viscose yarns. The yarns with different twisting coefficients and numbers were twisted and exposed to tandem and conventional vacuum steaming at different temperatures. Tenacity, unevenness, hairiness, twist liveliness, package hardness values, and spirality of knitted fabrics produced from these yarns were measured before and after vacuum steaming. The results obtained were assessed by means of COSTAT statistical analysis program. Variation analysis and SNK test were carried out at 5% (0.05) level of significance. The findings of this study indicate that the effects of vacuum steaming methods on the tenacity, unevenness, hairiness, twist liveliness and package hardness values of yarns are statistically significant. Although the effects of tandem vacuum steaming vary depending on the temperature applied and the raw material used, decreases are observed in unevenness, hairiness, twist liveliness and package hardness values of yarns. Apolteks Textil San. Tic. A.Ş Epiriler Textil San. Tic. A.Ş

In this study, two methods, the numerical simulation and the artificial neural network, are adopted to predict the vortex yarn tenacity from some process and nozzle parameters. The fiber-airflow interaction and the motional characteristics of the fiber inside the vortex spinning nozzle are analyzed through the numerical simulation method to predict the yarn tenacity from the parameters of the jet orifice diameter and the yarn delivery speed. The back-propagation multilayer perceptron (MLP) neural network is adopted to predict the tenacity of vortex yarn spun from modal fibers. The following parameters are used as inputs: nozzle pressure, jet orifice angle, distance between the guiding needle and the spindle, and spindle cone angle. The predicted and measured tenacities show low relative errors and a high correlation coefficient, indicating the artificial neural network method provides accurate prediction results. In addition, the effects of these parameters on the yarn tenacity are also analyzed.

The impact of staple strength on later stage processing of fine fleece wools (19 µm) and the blending with pieces is investigated. The staple strength findings complement those of previous researchers who used wools of different fibre diameters or from single flocks. The results reported here show that, as previously, the direct effect of staple strength is limited to the production of tops, where staple strength influences fibre length in the top and the generation of combing waste. Blending fleece wool and pieces was shown to increase combing noil and reduce fibre length in the top. The topmaking results conducted at CSIRO suggest that there may be an economic advantage in incorporating lower staple strength, and hence cheaper wools, in an all-fleeces consignment while still being able to meet the technical requirements for yarn and fabric production. Although statistically significant, the small tenacity and elongation differences for 1/64 Nm yarns produced from the high and low staple strength test batches appear to have had no significant impact on the fabric tensile properties. There were no inter-batch yarn evenness and fault level differences recorded, with top dyeing having a much greater influence on yarn quality than any differences associated with staple strength. Blending fleeces and pieces in a 60/40 ratio had a greater impact on processing from raw wool to fabric than the effect of staple strength over the range investigated. In comparison to an all-fleeces batch it would appear the economics of processing a fleeces-and-pieces batch may not be attractive, as the blend composition had an adverse effect on yarn fault levels, tenacity and elongation, which in turn may adversely affect weaving performance. However, the effect on fabric properties appears to be minor.

In this study, the effect of vacuum steaming temperature and time on the physical properties of polyamide (PA) 6 yarns has been investigated. Also, the effect of vacuum steaming temperature and time on twist liveliness and package hardness of PA 6 yarns has been studied and the results obtained have been evaluated using statistical methods. Further, the effect of vacuum steaming on dyeability properties of PA 6 yarns has been examined and the effect of vacuum steaming temperature and time on dye absorption properties of PA 6 yarns has been analyzed. As a result of this study, it has been seen that vacuum steaming temperature and time have significant effects on the tenacity properties, twist liveliness, package hardness, and dyeability properties of PA 6 yarns.

In this study, the effects of splicing parameters, fiber and yarn properties on the tenacity and elongation of spliced yarns were investigated in detail. For this purpose, yarns from eight different cotton types, having three different counts (29.5, 19.7 and 14.8 tex) and three different twist coefficients (α tex 3653, αtex 4038, αtex 4423) were produced. Fiber properties measured using an Advanced Fiber Information System fiber tester were evaluated. Artificial neural network and response surface models were used to analyze spliced yarn tenacity and elongation as dependent variables. As independent variables, fiber properties together with the machine settings such as opening air, splicing air and splicing time, yarn twist and yarn count were chosen. As a result of the study, equations and neural network models that predict the tenacity and elongation of the spliced yarns were obtained. The obtained equations and models are statistically important and have high coefficient of multiple determination ( R2).

The aim of this work is to explore a new method for producing spun yarn on a modified ring spinning system which is called “clusterspun yarn”. Here, we describe the effects of the clustering of polyester multifilaments on the internal structure and properties of a composite yarn. Cotton fibers and polyester multifilaments were spun into 19 Ne cluster and core-spun yarns at five different twist levels. These yarns were then tested to compare their properties, including tenacity, elongation, and evenness. Surface morphology and structural variations of cluster and core-spun yarns were studied by scanning electron microscopy. Microtome and image-processing methods have been used to study the structure and packing of fibers in the cross-section of yarns. The results show that the special structure of a cluster-spun yarn results in pronounced enhancement in the structural mechanics and yarn properties. The statistical analysis results indicate that the tenacity and breaking elongation of cluster-spun yarn is significantly more than that in core-spun yarn. The results show that the twist factor at about 3.9(α e) gives the optimum properties. In addition, lower twist is needed to produce quality yarn in cluster-spun yarns as compared with normal core-spun yarns.

This study investigated the tensile properties of a rotating or ballooning staple yarn. The results indicated that the effect of rotating speed on the tensile properties of a ballooning staple yarn was significant. As the yarn rotating speed increased, the tenacity of the rotating or ballooning yarn decreased, while the yarn breaking elongation increased. The effect of rotating speed on the tenacity of a ballooning staple yarn varied for different yarns. These results demonstrated that the breaking force of a ballooning yarn was much lower than the yarn breaking force obtained from normal tensile tests. These results provide new insight into the problems of yarn breakage in yarn spinning and twisting processes.

This paper reports the variability of mechanical properties of banana fibers with respect to diameter, testing speed and gauge length. We report interesting findings on banana fibers. Tenacity of the fibers significantly improved for the fibers with lower linear density. An increase in speed resulted in improvement of fiber properties to a certain degree. Higher gauge lengths resulted in poor properties due to an increase in flaws in the structure. The banana fibers showed very high variability in linear density and mechanical properties.

The structuring effects of the core and sheath on the tensile properties of core-spun yarns need to be systemized in order to meet potential application requirements. In this study, the core— sheath structuring effect was modeled theoretically, using a spring and damper as mechanical elements. Core-spun yarns with high tenacity filaments as the core and cotton staples as the sheath were prepared and tested to determine their tensile properties. Results demonstrated that the tensile system of the ring core-spun yarn could be described with four mechanical elements, two elements for the core-sheath geometry and two elements for the structuring effect. The core-spun yarns had a lower elastic modulus than the core filaments, and an easy viscous deformation of the core-spun yarn occurred with core spinning. Increasing the number of twists led to a consistent decrease in the strength of aramid core-spun yarn, while the high tenacity PET core-spun yarn had almost unaffected tenacity for various twist levels. The basalt core-spun yarn, however, demonstrated a twist factor level that indicated a potential maximum yarn tenacity. The breaking elongation of the aramid core-spun yarn had an increasing tendency with the number of twists. The high tenacity PET core-spun yarn remained in a limited range of elongation with twists. The basalt core-spun yarn had noticeably greater elongation as the number of twists increased.

Nonwoven materials have been used in ballistic protection applications because they offer the advantages of light and flexible fabrics. This study examined the ballistic protection efficacy of a nonwoven structure with high tenacity polyamide staple fiber as its main component. The nonwoven structure was reinforced with low-melt polyester fiber. High tenacity filaments were laid between two layers of polyamide webs and bonded via needle punching. The impact-resistant properties were assessed using dropped weight and bullet-shooting impact tests. The results of the dropped weight-impact test were used to examine the optimum processing conditions for composite nonwoven fabrics. Furthermore, the results of the bullet-shooting test were used to examine the ballistic protection performance of composite nonwoven fabrics. The experiment's results demonstrated that the cushion structure of composite nonwoven fabric could reduce non-penetration damage and increase the ballistic-resistant properties of bullet-resistant vest.

Enzymatic treatment of fabrics is known to have a negative impact on the fabrics' tensile characteristics. The strength loss problems would be more severe in the case of nonwovens, since cellulase could attack bonded areas of the fabric. To prevent the fabric strength loss, a study was undertaken to treat cotton fibers as opposed to the final fabric. Raw cotton fibers were hydrolyzed with Cellusoft L and endoglucanase without a cellulose— binding domain. Factors such as the reducing end group, fiber length and tenacity were followed throughout the enzymatic hydrolysis. The results showed that if the concentration of Cellusoft L cellulase mixture was minimized to 0.25 % owf, extensive weakening of cotton fibers could be prevented. Endoglucanase demonstrated a moderate reduction in fiber strength; most of the reduction occurred at the beginning of hydrolysis. The concentration of reducing ends was observed to have a maximum for both enzyme solutions. The location of enzymatic attack and changes in surface morphology were monitored by Congo red staining and scanning electron microscope, respectively.

The study was carried out to investigate the effect of nuts (almond, hazelnut, peanut, walnut) enrichment (5, 10 and 15%) on the rheological properties of dough using alveograph, consistograph and rheofermentometer measurements. The loaf volume (LV) of bread added nut paste was also determined. The increase in nut percentage increases the dough viscoelastic characteristics (tenacity, extensibility, and strength) and mixing time, but decreased the dough consistency and tolerance, and the CO2 production during fermentation. Loaf volume increased when 5 and 10% of nut paste are added. Dough added walnut paste presented the lowest tenacity, strength and water absorption values, but the highest values in dough development time, tolerance and stability. Dough added almond, hazelnut and peanut paste had a similar behavior during mixing and handling.

In this replicated experiment, we investigated the impact of cashmere on blends with superfine wools on the quality of tops, rovings, and worsted spun yarns. We also investigated the relative performance of soft, low crimp/low fiber curvature superfine wool when compared with cashmere and also when compared with traditional high crimp/high fiber curvature superfine wool in pure and blended yarns. The results indicate both the cashmere blend ratio and fiber curvature/crimp of wool affected processing requirements and the attributes of worsted pure and blended tops, rovings, and yarns. Adding wool to cashmere improved the processing of cashmere roving and reduced yarn faults. Mean fiber curvature was a good predictor of yarn hairiness and yarn tenacity.

In this study, the bundle elongation and tenacity of cotton fibers were measured using a modified tensile testing instrument to which Pressley clamps (1/8” gage length) were adapted. 32 cotton genotypes with a range of bundle tenacity and elongation were carefully selected based on their distinct physical properties. The work of rupture was calculated from the load vs. elongation curves for each type of cotton. Results demonstrated the importance of fiber bundle elongation in the work of rupture of fiber bundles, which is critically important to processing performance. This study lays a foundation for future efforts to calibrate the high volume instrument elongation measurements and to breed new cultivars with improved work of rupture. This should result in lower fiber breakage when the cotton fibers are submitted to different mechanical stresses (ginning, carding, spinning, and weaving).

The properties and structural parameters of compact and conventional ring yarns produced at five different twist levels were compared. A modified version of the tracer fiber technique ( J. Textile Inst., 43, T60-T66, 1952) combined with the Image Analysis Application Version 3.0 (B.A.R.N. Engineering) was utilized to explore yarn structure. Results obtained from these analyses showed that the high tenacity values of compact yarns can be attributed to the higher rate and amplitude of fiber migration in these yarns compared to those in conventional ring yarns. Another important finding was the superiority of compact yarns in terms of tensile properties is less noticeable at higher twist levels and in 50/50 polyester/cotton blend.

A generalized mathematical model has been developed for predicting the strength of spun yarns produced by ring, rotor, air-jet and open-end friction spinning systems. The model is based on the translation of fiber bundle tenacity into the yarn tenacity and it is applicable to all spun yarns. The model describes the failure behavior of spun yarns. Experimental strength results are compared with the predicted ones on the basis of theory, and a satisfactory agreement is reached. The limitations of the model are also analyzed.

An end break will occur in spinning when the tension in the balloon exceeds the strength at the weakest point in the yarn, which is at the point of twist insertion and before the fibers are fully twisted together. Other than gross faults such as slubs, the cause of an end break is generally a very thin place, the incidence of which can be estimated from the mean linear density of the yarn and its variance. A good correlation was found between the end breakage rate and the irregularity (CV%) of the yarn, which appears to be independent of yarn count. The tenacity of the yarn at a break was estimated to be only about 1.85 g/tex. For wool yarns which are woven in the warp as singles, end breaks in spinning effectively remove those thin places which are likely to break in warp ends during weaving. It is recommended that such yarns be spun at high speed to remove those short, very thin places which might not be detected in clearing, but which may fail in weaving.

Nearly all electrostatic dissipating yarns or fabrics are fabricated from a man-made carbon conducting core surrounded by a sheath of polyester or nylon, electroplated staple fiber, fabric or stainless steel staple fiber. Few electrostatic dissipating materials are spun from continuous, well conducting metal wires. This work uses metal wire as the core and fabricates the yarn using a ring-spinning machine. The copper and stainless steel wires were employed as core materials, and rayon and T/R (polyester/rayon) roving were used as cover materials. During the spinning process, the metal wire was fed from the front rollers and underwent drafted roving to spin yarn with a complex core. The guide device was designed and installed on the roller-weighting arm to increase the stability of spinning of the metal wire. Various parameters such as the core materials, the roving materials, the twist level and the count of the spun yarn were changed to investigate how various parameters affect the tenacity and hairiness of the complex core spun yarn.

Owing to growing demand for figure hugging and comfortable clothes made with stretchable fibers, spandex fibers are being used in underwear, diapers, hosiery, leisurewear, sportswear, jeans, and so on. In the present study a polyester core-spun yarn containing spandex fibers was made using a self-designed, multi-section drawing frame and a ring spinning frame. The mechanical properties of the core-spun elastic yarns were examined in various processing conditions. The analytical results show that when the main drawing ratio of the spandex fibers was either 2.2 or 2.7, the maximum breaking tenacity and elongation of the core-spun elastic yarns exceeded those in any other of the main drawing ratio conditions.

The SDL Quickspin System is designed to allow spinners to quickly evaluate raw cotton and observe its effects on the resulting yarn quality and spinning performance. This work reports on the effects of several critical processing parameters of the Quickspin System, including navel type, rotor speed, and sliver linear density, on the tenacity of Quickspin yarn. The results show that there are several significant effects of these critical parameters and their interactions on the tenacity of Quickspin yam. The navel type exerts significant effects on the tenacity of Quickspin yam. A higher tenacity, finer Quickspin yarn can be obtained at a lower rotor speed. Reducing the linear density of sliver is beneficial to the tenacity of Quickspin yarn. These findings confirm that the parameter settings of the Quickspin System closely match those of conventional rotor spinning adopted in normal yarn production. From this investigation of the interactions of the critical parameters, optimum settings of the Quickspin System can be obtained and used as a reference for spinners.

Two modeling methods are used to predict the tensile properties of air-jet spun yarns. A numerical simulation provides a useful insight into the flow characteristics and wrap ping formation process of edge fibers in the nozzle of an air-jet spinning machine. By analyzing the results of the numerical simulation, the effects of nozzle parameters on yarn tensile properties can be predicted. A neural network model provides quantitative predic tions of yarn tenacity. The effects of parameters on yarn tenacity are also determined by the neural network model. Excellent agreement is obtained between these two methods.

Case-based reasoning (CBR) is an advanced reasoning technique simulating how hu mans routinely solve problems. There are several steps in CBR: presentation of a new problem, retrieval of the most similar cases from the database of cases, adaptation of the most similar old solutions, validation of the current solution, and updating of the system by adding the verified solution to the database of cases. This study briefly demonstrates how CBR provides a new and alternative approach for understanding the complex rela tionships between fiber properties and predicting their influences on the resulting yarn qualities. This investigation reveals that CBR is sufficiently transparent for spinners to understand how the yarn strength of a particular cotton sample is derived.

Elastic fibers are mostly used in elastic textiles. In this study, we develop a novel and original method to make highly elastic complex yarns using a self-designed, multi-section drawing frame and rotor twister. We examine the mechanical properties of these elastic complex yams. Their maximum breaking tenacity is high when the speed of the rotor is 4000 rpm and the wrapping count of the textured nylon filaments is either 2.5 or 3.0 turns/cm. These data are useful for the textile industry.

Polypropylene (PP) filaments have become one of the most important industrial filaments. Fibers from advanced Ziegler-Natta and metallocene catalyst-based polypropylene have made inroads in technical textiles. High-modulus—high-tenacity PP filaments have found various uses in industrial applications on the basis of their superior properties and inert nature. The feed parameters as well as the processing variables - all have an important impact on the ultimate properties of PP filament, as has been observed by various researchers. This article critically reviews the production of high-modulus—high-tenacity PP filament along with proposed changes in microstructure leading to the superior mechanical properties. The contribution of crystallite and amorphous orientations, amorphous modulus, crystallinity, taut-tie molecules, and flaws in the shaping of mechanical properties of such filaments have been discussed. The chasm between practical and theoretical values in modulus and tenacity values are still large and a great deal of challenge involved in achieving high draw ratios. In most of the cases, high draw ratios have been achieved with single or multiple steps but with low strain rates and low processing speeds. Majority of the processes are batch processes and limits productivity.

INTRODUCTION Anyone who has been involved in the application of IEC 61508 (1) and the Safety Integrity Level (SIL) determination for Safety Instrumented Functions (SIF) will appreciate the amount of effort and tenacity that is required to undertake the task. However, the SIL determination of Safety Instrumented Functions, or trip functions as they are often called, is only the tip of an iceberg when we come to consider what is involved in reviewing or configuring a typical alarm system.

This paper investigates the effects of bond roll pattern and bonding temperature on the microstructure, tensile properties, flexural rigidity, and abrasion of polyethylene (PE) nonwovens. Bond roll variables include percent bond area, bond point concentration, and side-wall angle. Temperature greatly affects nonwoven mechanical properties. Of the various bond roll variables, bond point concentration significantly affects the elongation and flexural rigidity of PE nonwovens, whereas the side-wall angle affects tenacity. Microstructure analysis indicates that PE nonwovens fail by disintegration of the bond area rather than by fibers breaking at the bond perimeter. A one-dimensional, unsteady-state heat conduction model of the area under a bond point confirms that partial melting occurs in the center of thermally bonded areas.

The effect of a water jet pressure profile (WJPP) and initial web geometry on the properties of hydroentangled fabrics is investigated. Different web structures (obtained by parallel, cross, and air-laid formation) are produced and hydroentangled at the same total pressure but with different water jet profiles. Composite structures are also made by combining different web structures followed by hydroentangling. The fabrics are then characterized in terms of key physical properties. Although the total pressure may be constant, the WJPP influences the tensile properties of fabrics, especially those containing air-laid structures. The results also suggest that to produce high tenacity fabrics, the webs should be hydroentangled on both sides at almost the same total pressure. The MD/CD strength ratios indicate that the most isotropic fabrics are air-laid, composite web struc tures combining cross and parallel-laid webs.

This paper reports an investigation of the differences in structures and mechanical properties of two kinds of composite yarns and of conventional two-ply staple yarns. The cross section of one composite yarns (Sirofil) shows a circular shape, which is similar to the structure of single spun yarns and to the helical geometry line of two-ply yarns. The other composite yarn structure (twisted ring spun singles yarns with filaments) is similar to that of two-ply yams. The tensile properties of composite yarns mainly depend on the tensile properties of the filaments, and their tenacity is higher than that of two-ply wool/PET staple fiber yams. The bending rigidity of these two kinds of composite yams is lower than that of two-ply staple fiber yams. Wool/PET composite yarns show higher residual torque than conventional two-ply staple yarns, and the reason is their structure and lower torque-relaxation.