Chen Hung Huang

Electromagnetically shielding composite made from carbon fibers, glass fibers, and impact-resistant polypropylene Manufacturing technique and evaluation of physical properties

In order to create polymer composites that can shield machine and instrument casings from electromagnetism and to reclaim waste material, this study melt-blended impact-resistant polypropylene (PP) chips, carbon fibers (CFs; 5, 10, 15, or 20 wt%), and glass fibers (GFs; 0, 5, 7 wt%). This process used a single-screw extruder to make electrically conductive composites. The resulting composites were then evaluated in terms of mechanical properties, electromagnetic shielding effectiveness (EMSE), and surface resistivity. According to experimental results, an increase in CF content increased PP/CF composites’ tensile strength to 29.31 MPa and flexural strength to 38.93 MPa but decreased the impact strength to 49.04 MPa. When the CFs were increased to 15 wt%, the EMSE and surface resistivity of PP/CF composites were above 20 db and 3.3 × 103 Ω/square. For PP/CF/GF composites, with an increase in GF content, the EMSE decreased and the surface resistivity increased.

Property evaluation of Bletilla striata /polyvinyl alcohol nano fibers and composite dressings

This study used nonwoven manufacture and electrospinning to create wound dressings with solid mechanical properties and hemostasis function. 10% Polyvinyl alcohol (PVA) and 5% Bletilla striata (BS) were blended into the PVA/BS solution, which can be made into nanomaterial with high specific surface area by electrospinning. The PVA/BS solution was electrospun onto the dressing matrix made of polyester (PET) and absorbent cotton (AC), forming the PVA/BS composite dressings. According to the experiment results, when the volume ratio of PVA to BS was 9 : 1, the resulting dressings had optimal fiber formation, the finest average diameter, and the lowest toxicity.

Sound-Absorbing Evaluation on Nylon 6/Low-Melting PET Nonwoven Fabric

In recent years, as quality life improves, people begin to focus on quiet environment. Long-term noise pollution makes trouble of dysphoria and concentrating for people, thus noise-reduction has become an urgent project. This study uses Nylon 6 fibers, blended with different contents of low-melting PET fibers (10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%), to fabricate Nylon6/ LPET nonwoven fabrics after needle-punching process. Afterwards, their maximum tensile strength, air permeability, sound absorption coefficient were all evaluated. When low-melting PET fibers contain 30 wt%, the nonwoven fabric has the better sound-absorbing property. Herein, the maximum tensile strength reaches 70.79 N and 31.01 N, respectively in CD and MD; the air permeability is about 116.5 [cm3/(cm2/s)]

The Design and Optimization of Nonwoven Composite Boards on Sound Absorption Performance

This study aims to investigate the optimal value of design parameters for the sound-absorbing nonwoven composite board. The number of laminated layers and thickness of polyester fiber are viewed as the design parameters for fabricating the nonwoven composite board. The 2D, 7D and 12D polyester fibers are individually mixed with 4D low-melting point polyester fiber to produce 2D polyester nonwoven fabric (2D-PETF), 7D polyester nonwoven fabric (7D-PETF) and 12D polyester nonwoven fabric (12D-PETF) respectively. The developed nonwoven fabrics are then used to fabricate 2D-PET, 7D-PET and 12D-PET nonwoven composite boards through the multiple needle-punching and thermal bonding techniques. The sound absorption performance of each PET composite board is carefully examined. The experimental results reveal that the 7D-PET composite board with 10 laminated layers has the optimal sound absorption performance.

Processing Technique of Fiber-Based Composite Sound Absorbent/Thermal-Insulating Board

The rapid advances in technology have driven people for seeking ways to improve the quality of their living environment. While excessive noise is more likely to affect people physically and psychologically such as tiredness, dulling of the senses, lack of concentration, and reduction in work efficiency, etc, therefore, noise suppression has become an important research issue. In this research, 7 D polyester staple fiber and 4 D low melting point fiber have been used to fabricate the polyethylene terephthalate (PET) fabric through the process of opening, blending, carding lining, lapping, and needle-punching. Meanwhile, the contents of low-melting point polyester fiber are varied as 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% in PET fabric. The physical properties of PET fabrics are then evaluated after hot pressing process. Experimental results show that 50 wt% low-melting point polyester fiber is the best choice for PET fabric. Further, the techniques of lamination and multiple needle-punching are employed to make the PET/PP composite sound-absorbing board. A layer of polypropylene (PP) nonwoven selvages is placed between two layers of PET fabrics in the process of lamination. The PET/PP fibers casted into a mold are then put into a hot-air circulation oven around 170 °C for 10 minutes. Afterwards, the evaluation of PET/PP composite sound-absorbing board on sound absorption, flame resistance, thermal insulation, and relative mechanical properties is properly conducted.

Evaluation Mechanical and Sound Absorption of PET/PP and Nylon/PP Nonwoven Fabrics

With increase of life quality, demand for surrounding environment becomes more and more severely. Noise pollution in daily life lowers comfortablility and quiet of life. It is reduced accordingly if effective utilization of sound absorbing materials. This study uses polyester (PET) fibers and Nylon fibers bended with PP fibers respectively to form PET/PP and Nylon/PP nonwoven fabrics and then thermally bonded preparing PET/PP and Nylon/PP composites. The optimal parameters are evaluated by mechanical strength, and sound absorption tests. This study expects to prepare sound-absorbing composites in application of automotive interior and indoor building wall. Nylon/PP composites prepared in this study have the optimum sound absorption coefficient of 0.4 at high frequency, when containing 10 wt% proportions of PP fibers.

Effects of Foam Density and Content on Puncture Resistance and Cushioning Properties of PU/ Vermiculite Foam Composites

This study presents effects of foam density and vermiculite content of puncture resistance and cushion properties of PU/vermiculite foam composite for resisting against sharp objects and impact load. Results show that puncture resistance property improves significantly with foam density and slightly with increase of vermiculites. Cushion property becomes worse lower after vermiculite addition. With improvement of foam density, cushion property shows an uncertain trend. Besides, comparing with different contents of vermiculites, PU/vermiculite foam composite containing 5 wt% vermiculite has the lowest cushion property because vermiculite bonds with polar group among polar group among PU molecular.

Impact-Resistant Polypropylene/Short Glass Fiber Composites with Far-Infrared Emission: Manufacturing Technique and Property Evaluation

This study produces the far-infrared emitting composites by using impact-resistant polypropylene, short glass fibers, and far-infrared masterbatches. The addition of short glass fiber and far-infrared masterbatches is then evaluated to determine their influence on the mechanical properties and far-infrared emissivity of the resulting composites. The experimental results show that with an increase in the content of short glass fibers, the tensile strength increases from 34 MPa to 56 MPa, the far-infrared emissivity increases from 0.85 to 0.93, but the impact strength decreases from 1037 J/m to 197 J/m, proving that the resulting composites have desired mechanical properties and far-infrared emission.

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/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.