Chin-Mei Lin

Manufacturing techniques and electrical properties of conductive fabrics with recycled polypropylene nonwoven selvage

In this research, an original rotor twister machine, with a speed of 8000 rpm, spun complex ply yarns from recycled polypropylene nonwoven selvage (PPNS) and various metal wires. The core yarn was pieces of 30 g/m2 recycled PPNS and the wrap yarns were 80 μm stainless steel wires. Furthermore, 80 μm stainless steel wires and 80 μm copper wires, parallel to the core yarns, reinforced the complex ply yarns. Yarns were manufactured with wrap numbers of 0.5, 1.5, 2.5, 3.5, and 4.5 turns/cm. Complex fabrics were woven with the complex ply yarns as the weft yarns and PVC-coated PET filaments as the warp yarns. These fabrics were evaluated for surface resistivity and electromagnetic shielding effectiveness (EMSE). The presence of copper reinforcement wires was found to lower the surface resistivity of the fabrics. The lowest surface resistivity was recorded for a fabric woven from yarns with a wrap number of 4.5 turns/cm; that surface resistivity was 28.7 Ω/sq. EMSE measurements showed that fabrics with varied lamination angles provided good electromagnetic shielding. The optimum EMSE measured in this research was 56.1 dB on incident frequency as 2.36 GHz, for a fabric with 0°/90°/0°/90°/0°/90° lamination angles.

Physical properties of the functional bamboo charcoal/stainless steel core-sheath yarns and knitted fabrics

In this study, bamboo charcoal/stainless steel (B/S) core-sheath yarns were made of stainless steel wires and bamboo charcoal polyester textured yarn using a rotor twister machine. The speed of rotor twister was from 7000 to 11000 rpm and the wrapped amount varied from 2 to 7 turns/cm. The tenacity of 3.08 g/d was obtained when the speed of rotor twister was 8000 rpm and wrapped amount was 4.0 turns/cm. The tensile strain of 24.9% was yielded when the speed of the rotor twister was 7000 rpm and the wrapped amount was 5.0 turns/cm. The laminated amount of the knitted fabrics varied from 1 to 6 layers. The far infrared ray emissivity of the knitted fabrics was 0.934 when the laminated amount was 2 layers and wrapped amount was 6 turns/cm. Finally, the optimum anion density of the knitted fabrics was 610 ions/cm3.

Evaluation of the manufacture of sound absorbent sandwich plank made of PET/TPU honeycomb grid/PU foam

In this study, the sandwich plank consisted of 7D polyethylene teraphthalate (PET), thermoplastic polyurethane (TPU) honeycomb grid, and polyurethane (PU) foam; 7D PET and 4D low melting polyester fibers were needle-punched and thermal-treated so as to form the PET nonwoven layer. The PU foam was foamed with a different density in the mold so as to form the PU foam layer with a different thickness. Finally, PET nonwoven layer, TPU honeycomb grid, and PU foam layer comprised the PET/TPU/PU sandwich plank. The results indicated that the sound absorption coefficients of the specimens were over 0.93 for the frequencies ranging between 2000 and 4000 Hz.

Manufacturing and Properties of Fire-Retardant and Thermal Insulation Nonwoven Fabrics with FR-Polyester Hollow Fibers

Abstract In this study, nonwoven fabrics were manufactured using flame-retardant polyester (PET) hollow fibers (FR-PET fibers) and low-melting-temperature PET fibers (low-Tm fibers) for use as thermal insulation. Four nonwoven fabrics with different process routes were utilized to manufacture loose nonwoven fabric (LNF), thermal pressed nonwoven fabric (PNF), needle-punched and thermal pressed nonwoven fabric (NPNF), and needle-punched and through-air thermal bonded nonwoven fabric (NTNF). Thermal conductivity of these four nonwoven fabrics was assessed. Furthermore, LNFs were created using various thermal pressing temperatures (100, 120, 140, 160, 180, and 200°C), low- Tm fiber contents (10, 20, 30, 40, and 50%), and number of layers of nonwoven fabrics (1, 2, 3, 4, and 5 layer) to assess tensile strength, thermal conductivity, and the limiting oxygen index (LOI). Experimental results demonstrate that LNF had a low thermal conductivity of 0.5962 W/mK and the LOI of LNF was 35%.

Elucidating the Design and Impact Properties of Composite Nonwoven Fabrics with Various Filaments in Bulletproof Vest Cushion Layer

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 experiments 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.

Manufacture technique and performance evaluation of electromagnetic-shielding/far-infrared elastic warp-knitted composite fabrics

This study purposes to prepare elastic warp-knitted composite fabric which has multifunctions of shielding electromagnetic interference and emitting far-infrared ray, by altering number of rubber threads cycles. Bamboo charcoal/stainless steel wrap yarns were firstly formed via rotor twister machine, and then fabricated into three kinds of elastic warp-knitted composite fabrics using crochet machine beforehand different number of rubber threads was fed in. The mechanical, comfortability, and functional properties of resulting warp-knitted composite fabrics were evaluated afterward. Result shows that the maximum increase of breaking strength and shear strength of resulting elastic warp-knitted composite fabric was 329 and 176% respectively. The optimal far-infrared emissivity of single-layer warp-knitted composite fabric reached up to 0.9ε. Electromagnetic shielding effectiveness (EMSE) was promoted along with laminated layer and plied angle of composite fabrics. When laminated angle was arranged as 0°/90°/0°/90°/0°, EMSE of warp-knitted composite fabric reached 60 dB at incident frequency of 1988 MHz. The resulting elastic warp-knitted fabrics are applied as health care maternity belts, etc. in the future.

Process and Ballistic-resistant Buffer Effect of Cushion Composite Layer Made of Three-dimensional Crimped Hollow Fiber

This study utilized a 3D crimped hollow fiber web and high tenacity nylon-6 fiber web blended with low-melt polyester staple fibers to form a compound nonwoven fabric with a sandwich structure processed by needle punching and thermal pressing. The compound nonwoven fabric was layered with Kevlar fabric to form bullet-resistant complex fabrics. Impact properties and buffer effect were analyzed via the drop weight impact test and the bullet-shooting test. The compound nonwoven fabrics made of high-tenacity nylon-6 fiber and 3D crimped hollow fiber increased the buffer effect of ballistic resistance and decreased non-penetration damage and the layer of Kevlar fabrics. This study was expected to increase the safety of the ballistic resistant cloth and decrease its cost.

A simple JPEG-LS compressed technique for 2DGE image with ROI emphasis

Abstract In this paper, we proposed a JPEG-LS lossless region of interest compression scheme to compress images to smaller sizes and to preserve the significant protein data. The scheme involved manipulating NEAR of JPEGLS to compress the protein spots (ROI) in lossless mode and the non-ROI (unimportant) areas in lossy. Experimental results showed smaller size compressed 2D gel electrophoresis (2DGE) image, which can be recovered for its lossless ROI protein spots. The scheme can also be used to customise the size of compressed image by proportionally sacrificing the quality of the non-ROI areas of the image. The size to decrease would depend on the relative degree of distortion in the non-ROI that is acceptable to the user while the ROI protein spots remained undistorted.