Development of air textured core-and-effect glass yarns for improving the bonding strength of laminated composites

Delamination is the most common failure mode in laminated composites, due to the reduced strength in the through-the-thickness direction. This paper describes the development of core-and-effect textured glass yarns for improving the bonding strength of laminated glass woven fabric composites. Air-jet texturing introduces bulk and loops in the yarn which provides more contact surface between the fibers and the resin. However, the yarn tenacity decreases after texturing because of the reduced alignment of the filaments. The effects of texturing air pressure, yarn overfeed ratio, yarn linear density and core-sheath ratio were studied in this paper. The tenacity of glass yarns decreased significantly after the texturing process. The reduction was smaller for yarns with a higher core linear density. The effects of texturing air pressure on the tenacity were found to be insignificant.     

Properties of core-and-effect air textured yarns blended by diacetate and polyester filaments

In present work, PET FDY has been used to blend with diacetate filaments by air texturing process and core-and-effect air-textured yarns have been produced. The influences of both over-feeds of core and effect components on properties of textured yarns were mainly examined. It was observed that a spun-like effect of diacetate filaments occurred during air texturing and there were a little amount of free fiber ends besides loops on blended air textured yarns, while the number of free fiber ends changed little with variation in over-feeds. The tenacity of textured yarns decreased with increase in over-feeds of effect or core component. The breaking elongation increased with increase in over-feed of effect component, but decreased with increase in over-feed of core component. The yarn stability improves when both over-feeds are increased. The effect of over-feeds on boiling water shrinkage shows no clear trend. The core and average diameters are higher at high over-feed of effect component, but the over-feed of core component exhibits little effect on yarn diameters. The number and size of loops are increase with increased over-feed of effect component.     

Investigation on air texturing process for diacetate blending with polyester filaments

Influences of processing parameters on tensile property, stability and bulk of core-and-effect air textured yarns of diacetate and polyester filaments are mainly examined in this paper. When the air pressure is raised, the tenacity and breaking elongation of textured yarns are reduced, Instability I and II tend to decrease at first and then increase, the core bulk declines markedly at first and then changes slowly, whereas the overall bulk changes little at first and then goes up greatly. With increase in texturing speed, the yarn tenacity and breaking elongation both drop initially then begin to increase, the core bulk and overall bulk are almost linearly increased, while the yarn instability changes with an unclear trend. When the winding underfeed ratio is increased, the yarn tenacity, breaking elongation and core bulk are reduced, but the yarn stability is slightly improved. The wetting of the core component produces higher tenacity, breaking elongation, instability and bulk, compared with that of the effect component or that of both, but the difference is insignificant.     

Effect of blends proportion on the characteristics of dry and Pre-wet nylon/viscose blended air-jet textured yarns

Blending of nylon filament with viscose can overcome the drawbacks of these yarns. Thermoplastic and thermoset filament yarns can be blended in air-jet texturising method. The characteristics of nylon/viscose blended filament yarns are required to be understood in order to convert them in to useful products. Therefore, nylon/viscose blended yarns in different proportions were produced using nylon 6 and viscose filament yarns in air jet texturising machine. The textured yarns were also produced in dry and pre-wet conditions to understand the effect of water on textured yarn characteristics. It was found that the loops frequency, bulkiness of nylon/viscose blended textured yarns increase with increase in viscose proportion. The Loops stability, tenacity and breaking elongation decrease with increase in viscose proportion. Pre-wet textured yarn show higher loops, bulkiness, and good loop stability than their corresponding dry textured yarns.     

Improvement in the fracture toughness (Mode I) of laminated glass fabric composites through air-jet texturing

Delamination is the most common failure mode in laminated composites due to the reduced strength in the through-the-thickness direction. Air-jet texturing was used to provide more surface contact between the fibres and the resin by producing bulk and loops in the yarn. The development and characterization of core-and-effect textured glass yarns and the effect of texturing on the mechanical properties of laminated composites were presented in the previous papers. This paper describes the effect of texturing on the inter-laminar fracture toughness (Mode I) of glass laminated composites. The composites of twill weave fabrics were developed from both the textured and non-textured yarn and fracture toughness is tested in warp and weft directions. Significant improvement was observed in the Mode I fracture toughness of the composites after texturing. The bulkier, loopy structure of the textured yarn provided more surface contact between the fibre and the resin and significantly improved the bonding strength.     

The effects of texturing induced microstructural changes on the relaxation behaviour of polyamide 66 multifilament yarns

Polyamide 66 multifilament yarns are textured in order to be endowed the properties of natural staple fibre yarns for textile applications. Texturing changes crystallinity, orientation and promotes the formation of stable secondary links between the macromolecular chains. Two polyamide yarns with the same linear density but composed of filaments of different fineness were textured by the air-jet and the false-twist procedures. The microstructural changes induced by texturing modify the relaxation behaviour of yarns. By the application of the Nutting’s power law which relates stress, strain and time, the influence of texturing and filament fineness on the relaxation behaviour of the yarns stretched form 15% to 25% was studied. Relationships between Nutting’s model parameters and crystallinity, orientation and stability of secondary crosslinks formed during texturing were also studied.     

Effect of opening roller speed, drums speed difference and suction air pressure on properties of open-end friction spun polyester and acrylic yarns

The present paper is concerned with the influence of opening roller speed, drum speed difference and suction air pressure on properties of polyester and acrylic open-end friction spun yarns. The results shows that the opening roller speed and the suction air pressure have considerable influence on the characteristics of polyester and acrylic open-end friction spun yarns. In case of polyester yarns the unevenness, imperfection and hairiness decreases and the yarn tenacity increases with the increase in opening roller speed and suction air pressure. However for acrylic yarns the unevenness and imperfections decreases and tenacity increases with the increase in opening roller speed and suction air pressure.     

Mechanical properties of composites made from locally manufactured carbon fabrics and the composites produced from air-textured glass yarns

Composite materials have a wide range of applications in structural components because of their high strength-to-weight and stiffness-to-weight ratios. However, the most crucial and common life-restricting crack growth mode in laminated composites i.e. delamination is of great concern. Air jet texturing was selected to provide a small amount of bulk to the glass yarn. The purpose was to provide more surface contact between the fibres and resin and also to increase the adhesion between the neighbouring layers. These were expected to enhance the resistance to delamination in the woven glass composites. The development and characterisation of core-and-effect textured glass yarns was presented in the previous paper. This paper describes the comparison of the mechanical properties of composites produced from air-textured glass yarns and the composites made from locally manufactured carbon fabrics. The tensile, flexure and inter-laminar shear strength (ILSS) were compared and it was observed that although glass fibres are inferior to carbon fibres in terms of mechanical properties however, the flexure strength and ILSS of glass based composites increases after texturing and were found closer to the properties of carbon based composites.     

Comfort and handle related properties of P/V blended air-jet textured yarn fabrics

The effect of blend percentage on comfort and handle related properties of fabrics made from polyester/viscose blended air-jet textured yarn weft were studied and the results were compared with fabrics made from polyester/viscose ring-spun yarn wefts of similar linear densities. It is observed that with increase in polyester content in the blend, the air permeability and water vapour permeability reduces whereas thermal resistance, transverse wicking and shear rigidity increases both in ring-spun yarn and textured yarn fabrics and bending rigidity increases in textured yarn fabrics. Textured yarn fabrics exhibit lower air permeability and extensibility, higher thermal resistance, relative water vapour permeability, transverse wicking values and bending rigidity as compared to the ring-spun yarn fabrics.     

A comparison between the thermomechanical and structural changes in textured PET yarns after superheated steam and dry heat treatment

PET yarns textured at different texturing conditions were treated with superheated steam or dry heat at different temperatures for different times. The effects of the treatment conditions on the thermomechanical and structural changes of the yarn were examined by shrinkage, X-ray diffraction and birefringence measurements. With increase in superheated steam temperature, the crystalline orientation factor and birefringence decreased, whereas crystal size increased. Dry heat treatment had a smaller effect on shrinkage and structural properties in comparison with superheated steam treatment. The additional shrinkage after texturing process was investigated. The effect of heat-setting in both media was more significant at 200 °C. The time dependence of the properties was not linear.     

The effect of the processing factors on the physical properties of high shrinkable nylon composite yarns

This paper is aiming to develop high shrinkable differential shrinkage and mixed fibre nylon composite yarns by applying the high shrinkable polyester manufacturing technology. The wet and dry thermal shrinkages and mechanical properties of developed nylon composite yarns are measured and discussed with processing factors in the spinning and texturing processes. And the effects of the processing factors on the physical properties of high shrinkable nylon composite yarns are investigated. For this purpose, twenty seven nylon 30d/12f SDY were prepared with variation of spinning temperature, 2nd godet roller temperature and draw ratio on the spinning machine. The optimum spinning condition which showed maximum wet thermal shrinkage and stress was determined and high shrinkable nylon 30d/12f SDY spun under this optimum condition used as a core and three kinds of regular nylon filaments used as sheath were processed on the texturing machine with variation of 1st and 2nd heater temperatures. The optimum texturing process condition was decided through analysis of dry thermal shrinkage of these core and sheath nylon filaments. Finally, high shrinkable differential shrinkage and mixed fibre nylon composite yarns were made under the optimum texturing condition on the texturing machine, its wet thermal shrinkage was 13.8 %, which was much more higher than that of regular nylon composite yarns. The differential shrinkage effect of the developed nylon composite yarns was found in the yarn surface and cross section profiles by microscope and SEM.     

Moisture and thermal permeability of the hollow textured PET imbedded woven fabrics for high emotional garments

This study examined the effects of the total porosity, pore size, and cover factor on the moisture and thermal permeability of woven fabrics made from DTY (draw textured yarns) and ATY (air jet textured yarns) composite yarns with hollow PET (polyethylene terephthalate) yarns. The wicking of the hollow composite yarn fabrics was found to be superior to that of the high twisted yarn fabrics, which may be due to the high porosity in the hollow composites yarns, but this was not related to the cover factor. The drying characteristics of the hollow composite yarn fabric with high porosity were inferior compared to the high twisted yarn fabrics due to the large amounts of liquid water in the large pores, which resulted in a longer drying time of the fabric. The thermal conductivity of the hollow composite yarn fabrics decreased with increasing measured pore diameter due to the bulky yarn structure. The effects of the hollowness of the yarn on the thermal conductivity were more dominant than those of the yarn structural parameters. The air permeability increased with increasing measured pore diameter but the effects of the cover factor on the air permeability were not observed in the hollow composite yarn fabrics. The effects of porosity on the moisture and thermal permeability of the woven fabrics made from the hollow composite filaments were found to be critical, i.e., wicking and air permeability increase with increasing porosity. In addition, the drying rate increased with increasing porosity and the thermal conductivity decreased with increasing pore diameter, but were independent of the cover factor.     

Frictional characteristics of woven and nonwoven wipes

Demand for the fabric wipes is growing continuously. Wipes in industry are used for cleaning purpose. Cleaning involves rubbing action, so it is very important to know how much frictional force is encountered during the cleaning action. In this study the effects of normal load, sliding speed on frictional characteristics of nonwoven and woven wipes, both dry and wetted with different liquids, against glass and floor tile surfaces have been reported. With the increase in the normal load the coefficient of friction goes on decreasing for both nonwoven and woven wipes and this trend is observed in both dry and wet wipes. The coefficient of friction of both nonwoven and woven wipes against glass surface is in general higher than the floor tile surface. The wipes wetted with water shows an increase in coefficient of friction as compared to dry sample, but there is reduction in the coefficient of friction when the wipe samples are wetted with vegetable oil. In case of dry wipes, the coefficient of friction in case of nonwoven wipe is higher than the woven wipe. In case of woven wipes, the ranges of coefficient of friction either due to change in liquid type, normal load or sliding speed are in general smaller than that in case of nonwoven fabrics.     

A novel method to reduce hairiness level of ring spun yarn

The quality of ring spun yarns is largely determined by its level of hairiness. The existence of hairiness inevitably affects the quality of ring spun yarns. This paper presents an innovative method on lowering the level of hairiness of ring spun yarns. This can be achieved by shooting compressed air to the yarn, through a swirl nozzle comprising a yarn duct and an airjet nozzle attached to a traditional ring spin frame. When compressed air is applied from the air-jet nozzle to the yarn duct, the swirling air flow tucks surface fibers of the ring spun yarns into its body. Four controllable variable parameters for the process, supplied pressure, nozzle position, twist factor and spindle speed, and their effects on the lowering of yarn hairiness will be clarified. Their impact on the quality of the yarn is statistically analyzed, and the optimum outcome of the combination of parameters for the process, will thus be determined.     

Statistical Modeling of Thermal Properties of Biobased Compostable Gloves Developed from Sustainable Polymer

Polylactic acid (PLA) is a biodegradable and compostable polymer obtained from annually renewable resources and is acknowledged to be sustainable and non-polluting polymer with substantial commercial prospective as a textile fiber however, there is lack of literature on apparel applications of this polymer. Therefore in this study it was aimed to develop biobased compostable gloves from PLA draw textured melt spun yarns and to examine the effect of yarn linear density, fabric structure and stitch density on thermo-physiological comfort and moisture management properties of PLA based gloves. 100 % PLA based multifilament yarns of two different linear densities were melt spun and later draw textured on false twist texturing machine to be used for gloves knitting. Single jersey and rib structures were produced with two different stitch densities to investigate their effect on thermal conductivity, thermal resistance, relative water vapour permeability, air permeability and moisture management properties of the gloves. Minitab statistical software was employed to analyze the results of test samples. The coefficients of determinations (R² values) presented good estimation capability of the established regression models. The outcomes of this research may be useful in determining suitable manufacturing requirements of PLA based gloves to accomplish precise thermo-physiological and moisture management properties.     

Study on splicing performance of different types of staple yarns

The present paper reports the detailed study on the splicing behavior of viscose staple fiber yarns made from ring, rotor, friction and air-jet spinning technologies. The linear density of all the yearns was kept constant at 29.5 tex. The splicing parameters like splicing pressure and duration of the splicing were taken as variables. Three levels of splicing pressure at constant splicing duration and three levels of splicing durations at constant splicing pressure were considered. Splices were introduced at all these levels for the four different technologies. These splices were tested for their tensile properties and the properties of splices were evaluated in terms of retained splice strength (RSS) and splice break ratio (SBR). The splice photographs were taken and splices were analyzed for their structure and for diameter profile along the length of the splice.     

Comfort characteristics of fabrics made of compact yarns

Comfort is one of the most important aspects of clothing. Thermal comfort is related to fabric’s ability to maintain skin temperature and allow transfer of perspiration produced from the body. Properties like thermal resistance, air permeability, water vapor permeability, and liquid water permeability are suggested as critical for thermal comfort of clothed body. In this study the fabrics developed from the EliTe compact yarns are compared with the fabrics made from normal yarns. The thickness of the fabrics made from EliTe® compact yarns is also slightly less than the fabrics made from normal yarns. Fabrics made from EliTe® compact yarns have shown greater air permeability as compared to the fabrics made from normal yarns. It is observed that, thermal resistivity values of the fabrics developed from EliTe® compact yarns are lower than the fabrics made from normal yarns indicating they are cooler fabrics compared to normal fabrics. Fabrics developed from the EliTe® compact yarns have shown slightly higher values of MVTR (moisture vapor transmission rate) as compared to the fabrics made from the normal yarns. The wicking characteristic of fabrics developed from EliTe® compact yarns was slightly higher than the fabrics developed from normal yarns.     

Preparation and characterization of melt-spun PVC filament yarns

Polyvinyl chloride (PVC) fibers were melt-spun to prepare mono and multifilament yarns. To find optimum spinning and drawing conditions, various parameters such as spinning temperature, spinneret diameter, drawing temperature, and drawing ratio were examined. From the observation of the spinnability under various conditions, we found that the optimum conditions were as following: the extrusion temperature and die temperature were 175–180°C and 185–190°C, and the drawing temperature and drawing ratio were 85–95°C and 3.4, respectively. Under these conditions, the spinneret diameter could be reduced to the minimum value, 0.5 mm. Spun PVC filament yarns were subjected to the different yarn texturing process of stuffing box and pin false-twist method. The PVC yarn fabric was prepared by the knitting of textured yarns. Finally, the anion-emission and antibiotic properties of the knitted PVC fabrics were precisely evaluated.     

Effect of fiber friction, yarn twist, and splicing air pressure on yarn splicing performance

The impact of fiber friction, yarn twist, and splicing air pressure on mechanical and structural properties of spliced portion have been reported in the present paper. The mechanical properties include the tensile and bending related properties and, in the structural properties, the diameter and packing density of the splices are studied. A three variable three level factorial design approach proposed by Box and Behnken has been used to design the experiment. The results indicate that there is a strong correlation between retained spliced strength (RSS) and retained splice elongation (RSE) with all the experimental variables. It has been observed that RSS increases with the increase in splice air pressure and after certain level it drops, whereas it consistently increases with the increase in yarn twist. The RSE increases with the increase in both fiber friction and yarn twist. It has also been observed that the yarn twist and splicing air pressure have significant influence on splice diameter, percent increase in diameter and retained packing coefficient, but the fiber friction has negligible influence on these parameters. Yarn twist and splicing air pressure has a strong correlation with splice flexural rigidity, where as poor correlation with retained flexural rigidity.     

Investigation on the physical and structural properties of melt-spun multifilament yarns,drawn yarns and textured yarns produced from blend of PP and oxidized PP

In the present study, effect of OPP (oxidized PP) fraction on the mechanical and structural properties of produced fibers is investigated. Polypropylene powder without antioxidant materials was oxidized at the suitable thermal condition. The various fractions of OPP were blended with PP in the chips shape, and employed as starting material in a melt spinning machine for production of filament yarn. Then as-spun filaments were drawn and finally textured. Structural properties including density, birefringence and FTIR and physical properties consisting of shrinkage, tensile properties and crimp properties were measured. Results show that blending of OPP with virgin PP reduces tacticity and crystallinity, but it hasn’t any effect on orientation. Physical properties of drawn yarns and textured yarns were reduced with increasing of OPP fraction. Moreover, increasing of OPP fraction in blend, reduce crimp properties of textured yarn.