Textured Filaments Research Articles

Biodegradable Polyamide 6.6 for Textile Application

The study evaluates comparatively some physical and chemical properties of polyamide 6.6 standard and biodegradable. It also evaluates the period of biodegradation of the biodegradable yarn sample and standard sample. The physical properties analyzed were tensile strength, elongation, and tenacity. The chemical properties were related to the behavior of the samples in dyeing and the evaluation of subsequent strength dyeing. The evaluated samples were taken from knitwear produced with polyamide textured filament yarn 80 dtex f 68x1, standard and biodegradable, being purged, bleached, and dyed. The results of the physical tests, although statistically different, have values ​​very near the average, which in practice represent acceptable values ​​within the statistical control process. Both standard and biodegradable samples had the same chemical behavior and there is no difference. Concerning to biodegradation time under laboratory conditions, the carbon dioxide produced by the samples was monitored and measured to determine the percentage of biodegradation according to ASTM D 5511. After 735 days the percentage of biodegradation of the biodegradable yarn was 81.7% and of the normal yarn was 5.2%. This is an expressive gain in ecological terms for synthetic fiber.

ATY 노즐 직경에 따른 방호의류용 아라미드와 아라미드/나일론 하이브리드 ATY사의 물성변화

This paper investigates the physical properties of aramid and aramid/nylon hybrid air jet textured filaments for protective garments relative to ATY nozzle diameters. Three types of para-aramids(840d, 1,000d, 1,500d) and nylon(420d) filaments were prepared; in addition, 840d aramid/420d nylon and three kinds of aramid filaments were texturized with a variation of air jet nozzle diameters(0.6, 0.75, 1 and 1.2 mm) on the AIKI air jet texturing machine. The measured physical properties of 16 specimens are as follows. The linear densities of aramid and aramid/nylon hybrid ATY increased with a larger nozzle diameter. The tenacity and initial modulus of aramid and hybrid ATY linearly decreased with a larger nozzle diameter; in addition, the breaking strain increased with the nozzle diameter. The dry and wet thermal shrinkage of hybrid ATY increased with a larger nozzle diameter from 0.6 mm to 1 mm and then decreased at a nozzle diameter of 1.2 mm (which seems to be a critical diameter). The wet and dry thermal shrinkage of aramid/nylon hybrid ATY are influenced by the nylon part of the hybrid yarns because the wet and dry thermal shrinkages of aramid ATY are less than 0.2%. The instabilities of aramid and aramid/nylon hybrid ATY were not influenced by the air jet nozzle diameter; however, they increased with the linear density of ATY.

Relationship between microstructure and properties of false-twist textured and stabilized polylactide. Part 1: dimensional stability, mechanical properties and thermomechanical behavior

Polylactide fibers (PLA), false-twist textured at different temperatures (135, 150 and 165℃) and draw ratios (1.30, 1.35 and 1.40) were stabilized by a continuous setting treatment at 50 m/min and 100℃ using a specially designed chamber. The crystallinity and the orientation of the original textured filaments and those of the stabilized ones were measured. The effect of post setting on the dimensional stability, mechanical properties and thermomechanical behavior in accordance with the texturing conditions was studied. The relationships between crystallinity and the dimensional stability and between the orientation and both the relaxation shrinkage and the endset temperature of shrinkage were considered.

Effects of Heat Shrinkage on Structure and Property of Silk/Synthetic Fiber Textured Composite Filaments

The textured yarn was respectively prepared with pure silk, silk/polyester POY composite filament, silk/polyester FDY composite filament by the self-made processing device. The effects of heat shrinkage of polyester fibers on the structure and properties of the textured filaments were investigated. The results revealed that silk/POY composite filament contained higher heat shrinkage. Synthetic fibers produced crimps with larger amplitude and smaller bandwidth, and the textured filaments presented a larger yarn count, resulting in the notable crimped deformation.

Melt spinning of reused nylon 6: structure and physical properties of as-spun, drawn, and textured filaments

Polymers are considered to be important environmental pollutants. Polyamide 6 (PA6) is an example of an expensive monomer compared to other polymers. Thus, its recycling seems to be necessary in order to avoid environmental pollution and for the economical reuse of its wastes. To determine the feasibility of industrial processing of waste nylon, new and recycled PA6 chips with different blend ratios were melt spun. As-spun yarns were subjected to drawing and draw-texturing processes. Fiber structure and physical properties of yarn samples were measured and evaluated. Results showed that viscosity and molecular weight of samples with recycled PA6 displayed higher loss compared to the new PA6 fibers after melt spinning. Birefringence of recycled PA6 as-spun yarns was lower than that of new PA6. This difference was compensated by the drawing. In general, noticeable differences were not seen between the fiber structure and tensile properties of new and recycled samples. However, crimp properties of recycled PA6-textured yarn showed higher values than those of new PA6 fibers.

Wicking mechanisms in yarns—the key to fabric wicking performance

In view of the interest in wicking as an alleged comfort feature for active and leisure wear an analysis of the wicking and liquid retention properties of nylon 6.6 continuous and textured filament yarns commonly used for lightweight high performance woven fabrics was carried out taking into consideration the effects of yarn structure and static tension. The yarn wicking performance was significantly affected by the tension applied and the twist inserted. The heterogeneity of pore size, shape and orientation affected the penetration of the liquid into the yarn structure and hence its liquid retention properties as exhibited by the textured continuous filament yarns. Microscopic examination of the yarns showed unsaturated, saturated and dry zones.

Laser Fusion to Impart Cohesion to Textured Filament Yarns

The conventional intermingling process uses a high-speed air jet, positioned in the path of the yarn being textured; to create knot-like intermittent entangled nodes (‘nips’ or ‘tacks’) in the textured thermoplastic continuous multi-filament yarn. This paper reports a proof-of-concept research into the use of a pulse laser to fuse such yarns at discrete points at regular intervals along its length to impart cohesion at required frequencies. Pulse frequency and duration, hence the heat intensity, are varied to determine a suitable range of operating conditions. Results from a range of polyester and nylon yarns show that fusing textured filament yarn to create nips is feasible using a pulse laser as an alternative to intermingling by air jets. The multifilament yarn is also modeled to compute the heat flow in the yarn when heated by a pulse laser. This model can be used, as a tool to estimate the heat energy required to fuse a given textured yarn.

Development of Ag-sheathed wires based on Bi compounds

We are developing three types of Bi-based superconducting tape. In BiPb-2223 long tape, critical current densities ( J c: criterion 1 μV/cm) at 77 K were 33 and 29 kA/cm 2 for 120 and 850 m tape, respectively, This difference was caused by the 2223 phase purity in filaments. In 100 m class Bi-2212 tape, the J c of 11 kA/cm 2 was obtained by the reduction of filament sausaging. A short BiPb-2212 tape had low transport ability even if it contained good textured filaments. However, it was revealed that the BiPb-2212 tape had higher T irr than that of overdoped Bi-2212 tape with the keeping of high critical temperature ( T c). It was indicated that the BiPb-2212 phase basically had high performance against magnetic field in tape shape.

Evaluating Yarn Crimp with Fractal Geometry

Fractal geometry is used to evaluate the irregularities of crimped filament yarns. To measure the fractal dimension of textured filament yarns, methods based on the box counting dimension, the compass dimension, and the equipaced dimension are applied to digital images of the textured filament yarns, obtained using a charge coupled device (CCD) camera. For textured PET filament yams, as the crimp and twist level increase, higher values of fractal dimension are obtained, confirming that the fractal dimension can be used to evaluate fiber crimp. The fractal dimension and crimp also show an exponential relationship, which is well verified experimentally. Therefore, time-consuming direct measurements of fiber crimp may be effectively replaced by this automatic process, based on the acquisition of crimp images and fractal dimension analysis. The ideal sine wave. which has an equal length, crimp, and twist per meter, is synthesized as a topological model to study the physical properties of crimped yarn. This sine wave study shows that the major parameter of the crimped structure is the period of the crimp, and the dominant effect of yarn shrinkage development in boiling water is the increment of crimp amplitude.

Tensile Properties of Textured Polyester Woven Fabrics: Theoretical Model for Plain Weave Fabric

A force-geometric model is developed to predict the stress-strain relationship of textured polyester woven fabrics for small strains. The model is based on yarn param eters, fabric geometry, and force equilibrium principles. Strains due to removal of weave crimp, removal of textured yarn crimp, and extension of textured yam filaments are assumed to be in series and then summed to yield total predicted fabric strain as a function of stress. Only two strain components are considered: strain due to weave crimp removal and to textured yarn crimp removal. The analysis adopted by Johnson is used to derive the weave crimp component. Predicted stress-strain curves are com pared to experimental curves for eight different fabrics representing two levels of feed yarns and four levels of textured yarns; the fabrics are in the dyed state, having been woven and hot water bulked prior to jet dyeing. In this state, these textured woven fabrics have maximum stretch potential resulting from yarn crimp in the woven fabric and textured filament crimp generated during wet finishing. There is good agreement between experimental and predicted stress-strain curves for low modulus fabrics, but agreement between predicted and experimental values is not good in all cases.

Multifilament BPSCCO superconductor: fabrication and heat treatment study

The fabrication of long lengths of multifilament antimony-doped BPSCCO (Bi/sub 1.6/Pb/sub 0.3/Sb/sub 0.1/Sr/sub 2/ Ca/sub 2/Cu/sub 3/O/sub x/) wire or tape by conventional processing methods is reported. A combination of intermediate heat treatment followed by rolling and final anneals is utilized to obtain textured filaments in a silver matrix. The addition of antimony has been found to improve the irreversibility line as compared to the undoped samples, which may be useful for obtaining improved performance in BPSCCO wires. >

Factors Affecting the Dimensional Properties of the Cotton 1×1 Rib Knitted Fabrics

The effects of some factors on the dimensional parameters (Us=Cu×Wu×lu2=Su×lu2, Uc=Cu×lu, Uw=Wu×lu, and Uc/Uw = Cu/Wu, where lu is the total length in the SKC, Cu is course units/unit fabric length, Wu is wale units/unit wide and the SKC is the smallest repeating unit of the structure) and t/l (where lu is the fabric thickness and l is the loop length) of 1 × 1 rib knitted fabrics are investigated experimentally, using the cotton yarns (30s//3, 20s/2 or 30s/3) and the nylon sewing threads (from raw or textured filament yarns).For the 1 × 1 rib fabrics knitted from the nylon sewing threads, U-values are approximately constant, but t/l increases with the increase of the fabric tightness (K = n√T/lu, where n is the number of loop in the SKC and T is the yarn linear density in tex).The results obtained for the cotton 1 X 1 rib knitted fabrics are as follows : (1) For all fabrics after each relaxation treatment (DR, WR, BR, LR (1), (2) and (3) are the dry, wet, boil wash (1), (2) and (3) relaxation treatments respectively), Uc and t/l increase with the increase of K.(2) For all fabrics after each relaxtion treatment espect for LR (2) and (3), Uc/Uw increases with the increase of K, but Uw and Us decrease with the increase of K.(3) For the fabrics knitted from 20s/2 or 30s/3 after LR (2) or (3), Uc/Uw and Uw show a similar tendency to those obtained after DR, WR, BR and LR (1).(4) For the fabrics knitted from 30s//3 after LR (2) or (3), Uc/Uw and Uw over a range of K > 13 show a similar tendency to those obtained after DR, WR, BR and LR (1), but Uc/Uw and Uw over a range of K≤13 show a reverse tendency to those.(5) After LR (2) or (3), Us-values of the fabrics knitted from 20s/2 or 30s/3 are independent on K, but Us for 30s//3 increases with the increase of K.