Ching Wen Lin

Evaluation on the Sound Absorption and Mechanical Property of the Multi-Layer Needle-Punching Nonwoven

In this research, we used the special needle punching process to improve the disadvantages of the ordinary needle punching process. First, we manufactured the single-layer needle punching nonwoven by the ordinary needle punching process and then nonwovens were laminated followed by needle punching. We carried on this manufacturing processing until the multiple needle-punching nonwoven reached the certain thickness and area weight which were both limited in the ordinary needle punching process. The combination of two manufacture techniques as multiple thermal bonding and multiple needle-punching freed the single needle-punching from the limit of the expected thickness and area density. In this research, we tested the mechanical properties and sound absorption of the multi-layer needle-punching nonwoven and multi-layer thermal bonding nonwoven. According to the results, the tensile strength is higher than the multi-layer thermal bonding nonwoven; however, there was no distinct difference between the multi-layer needle-punching nonwoven and multi-layer thermal bonding nonwoven on the sound absorption performance.

Electromagnetic Shielding Effectiveness and Manufacture Technique of Functional Bamboo Charcoal/Metal Composite Woven

In order to fabricate textiles with electromagnetic shielding effectiveness (EMSE) and far infrared emissivity, we fabricated bamboo charcoal/metal (BC/M) composite wrapped yarns with metal wires (stainless steel wires or copper wires) as the core yarn and bamboo charcoal textured yarn as the wrapped yarns using a rotor twister machine. The optimum manufacture parameters included: the speed of the rotor twister was 8000 rpm and the wrapped amounts of the BC/M composite wrapped yarns were 4 turns/cm. The BC/M composite wrapped yarns were made into the BC/M composite woven fabrics using a loom machine. Moreover, we tested the BC/M composite woven fabrics in EMSE and then changed the lamination angles. When the lamination amount was 6, laminated angles were 0°/45°/90°/-45°/0°/45°, 0°/ 90°/0°/ 90°/0°/ 90°, and the frequencies of the incident waves were between 1.83 and 3 GHz, the EMSE of the BC/M composite woven fabrics reached 50 to 60 dB which was satisfactory.

The Effects of Thermal Consolidation Methods on PET Nonwoven Composites for Thermal Insulation Use

As available energy sources have grown increasingly scarce, people have started paying attention to their energy consumption. Although many methods for power generation are being actively investigated, efficient methods for solving energy problems must be based on reducing energy consumption. Thermal insulation can decrease heat energy loss and conserve energy waste, especially in the construction, transportation and industrial fields. In this study, polyester (PET) hollow fibers were blended with various ratios of low-melting-point PET fibers (10%, 20%, 30%, 40% and 50%). The fibers were blended using opening, carding, laying and needle punching (150 needles/cm2, 225 needles/cm2 and 300 needles/cm2) to prepare PET nonwoven fabrics. The PET nonwoven fabrics were thermally plate pressed (TPP) and air-through bonding (ATB). Thermal conductivity, physical properties and air permeability were investigated to identify the influence of manufacturing parameters on the PET nonwoven fabrics. The experimental results show that needle punching density, TPP and ATB would influence the thermal conductivity of PET nonwoven fabric, because the structure of PET nonwoven fabric was changed. The optimal parameters of PET nonwoven fabric clipped with an aluminum foil was used to evaluate the influence of aluminum foil on thermal conductivity. The PET nonwoven composite in this study can be used in industrial thermal insulation applications.

Preparation and Evaulation of Degradable Poly(lactic acid) Composite Dressings

Chitosan and sodium alginate are two prominent biomaterials because they have some unique properties such as good biocompatible and biodegradable. In this study, sodium alginate was as swelling and moisture retention layer; Chitosan was antibacterial layer.Polylactic acid (PLA) blended in different weight ratios with low melting point polylactic acid (LMPLA) to fabricate nonwoven fabric which reinforced by needle punching and hot pressing. Afterward, chitosan/ sodium alginate compound solution were treated by UV light in order to form cross-linking. Then chitosan/ sodium alginate compound solution coated on the PLA nonwoven fabric to make PLA composite dressings. The mechanical properties of chitosan/ sodium alginate membrane and dressing were measured. The optimum parameters of chitosan/sodium alginate composite membrane was treated by UV light for five minutes and the volume ratio of chitosan (3 wt %) and sodium alginate (1 wt %) solution was 8:2. After we coated chitosan/sodium alginate solution on PLA nonwoven fabric, the Tensile strength, and tear strength were upgraded by 80 % and 98 %; its air permeability and flexibility length, however, dropped by 18 % and 60 %, respectively.

Manufacturing Technique and Properties Evaluation of Ni-Coated Copper Composite Fabrics

The existence of the electromagnetic radiation may lead to diseases, which also includes cancer and cause the repellence of electrical compatibility. The textiles which have electromagnetic shielding effectiveness become more important in modern life. In the research, the PET/ Ni-coated Copper composite yarn were made by the wrapping machine, which the core yarn is Ni-coated Copper wire and the wrapped yarn is PET filament. After that, the composite yarn is fabricated by the automatic sampling loom into woven fabrics and had the tests of mechanical properties and electromagnetic shielding effectiveness. The test results revealed that the EMSE of the PET/Ni-Cu complex woven fabrics is 32.28dB, which the test frequency is 900 MHz, laminated layer number is 3 and the laminated angles are 0°/45°/90°, respectively.

Preparation and applications of polyamide 6/IRM® tooth root composite filling material

Intermediate restorative material (IRM®) is the most commonly used temporary filling material. This research mixed IRM with Polyamide 6 (Nylon 6) fibers, forming the Nylon/IRM tooth root composite filling materials. Tests such as setting time, degree of solubility, compressing strength, and micro-leakage were carried out to examine the properties of the Nylon 6/IRM® composite material. The result showed that there was no significant difference in the setting time and degree of solubility after adding the Nylon 6 fibers. The loading after the yielding point of the Nylon 6/IRM® was more than 250 N; micro-leakage was found on the 13th day.

Manufacturing Technique and Property Evaluation of Impact-Resistant Polypropylene/Glass Fiber Composites

Using the injection molding method, impact-resistant polypropylene (PP) and glass fibers (GF) with weight ratios of 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% and 30 wt% were blended twice, completing high-impact PP/ GF composites. Next, the tensile strength test, flexural stress test and IZOD impact strength test measured the composites. According to the results, with an increase in glass fibers, the composites exhibited a greater tensile strength, which further reached to climax when the GF weight ratio was 25 wt%. However, tensile strength appeared inversely proportionate to the blending frequency. In addition, regardless of blending frequencies, the optimum flexural stress occurred when the GF weight ratio was 25 wt%; nevertheless, it started declining when the ratio was 30 wt%. Finally, indicated by IZOD impact test, the greater the GF weight ratio, the lower the impact strength the composites exited.

Property Evaluation of Sound-Absorbent Nonwoven Fabrics Made of Polypropylene Nonwoven Selvages

The rapid development of textile industry at the beginning of the Industrial Revolution results in the invention of synthetic fibers. As synthetic fibers cannot be decomposed naturally, significant textile waste is thus created. Selvages, which make up the majority of our total garbage output, have a low value and thus are usually sold cheaply or outsourced as textile waste. This study aims to recycle and reclaim the nonwoven selvages which are discarded by the textile industry. The recycled polypropylene (PP) selvages, serving as a packing material, and 6 denier PP staple fibers are made into the recycled PP nonwoven fabrics. The resulting nonwoven fabrics are subsequently tested in terms of maximum tensile breaking strength, tearing strength, surface observation, thickness measurement and sound absorption coefficient.

Preliminary Study of Polypropylene/Coir/Carbon Black Conductive Wood Plastic Composite

Our living environment is full of diverse electronic products, making conductive polymer a popular subject for researchers. Insulating polypropylene (PP) can be improved in terms of conductivity by intermingling with electroconductive materials. Carbon black and carbon fiber are two materials that can supplement electroconductive and mechanical properties in insulating polymer materials. In this study, natural coir is first alkali-treated and then melt-blended with PP and carbon black, forming the composite. The resulting composite is tested in terms of its electromagnetic shielding effectiveness and mechanical properties. According to the results, when the amount of carbon black is 12 wt% and coir 3 wt%, the composite displays the optimum electromagnetic shielding of -23.56 dB, tensile strength of 37.07 MPa, and flexural strength of 47.21 MPa.

Preliminary Study of Polypropylene/Sawdust Green Composite

In this study, sawdust and polypropylene (PP) are melt-blended and injection-molded to form the wood-plastic composite (WPC).The WPC is then tested in terms of mechanical properties and compared with control groups of pure PP plate and PP/glass fiber (PP/GF) composite. In the tensile test, the WPC displays a tensile strength of 25-27 MPa, regardless of whether the sawdust content is 5, 10, or 15 wt%. Pure PP composite has a tensile strength of 30 MPa; PP/GF composite with 15 wt% glass fibers has a tensile strength of 57 MPa. In the bending test, the WPC displays a flexural strength of 44-45 MPa as the sawdust content does not influence the bending strength. PP/glass fiber composite yields a bending strength of 85 MPa when the content of glass fiber is 15 wt%. WPC is 5% lighter than PP/glass fiber composite.