Vibration Isolation Properties of Novel Spacer Fabric with Silicone Inlay.

Spacer fabrics are good for impact force absorption and have the potential for vibration isolation. Inlay knitting of additional material to the spacer fabrics can give reinforcement to the structure. This study aims to investigate the vibration isolation properties of three-layer sandwich fabrics with silicone inlay. The effect of the presence of the inlay, inlay patterns and materials on the fabric geometry, vibration transmissibility and compression behaviour were evaluated. The results showed that the silicone inlay increases the unevenness of the fabric surface. The fabric using polyamide monofilament as the spacer yarn in the middle layer creates more internal resonance than that using polyester monofilament. Silicone hollow tubes inlay increases the magnitude of damping vibration isolation, whereas inlaid silicone foam tubes have the opposite effect. Spacer fabric with silicone hollow tubes inlaid by tuck stitches has not only high compression stiffness but also becomes dynamic, showing several resonance frequencies within the tested frequency range. The findings show the possibility of the silicone inlaid spacer fabric and provide a reference for developing vibration isolation materials with knitted structure and textiles materials.

Evaluation of the design and materials of anti-vibration gloves: Impact on hand dexterity and forearm muscle activity.

Many anti-vibration gloves are available in the market but there are lacks of understanding of their effectiveness in facilitating various hand movements. This study addresses the knowledge gap through a wear trial with five types of anti-vibration gloves made of chloroprene rubber and spacer fabric. Surface electromyography of three forearm muscles of 16 male subjects was conducted during gripping, key pinching, woodblock transporting, screw inserting and screw driving tasks. The correlation between the compression properties of the gloves and hand performance was also evaluated. The results show that hand dexterity is inhibited and more muscle activity is needed to carry the woodblocks with the spacer fabric glove without special design features. A thicker glove can reduce the demand of the flexor digitorum superficialis muscle when using an impact driver. A thinner dorsal side and tailored padding can enhance hand dexterity. The findings can be used as a reference for designing anti-vibration gloves.

Effect of Silicone Inlaid Materials on Reinforcing Compressive Strength of Weft-Knitted Spacer Fabric for Cushioning Applications.

Spacer fabrics are commonly used as cushioning materials. They can be reinforced by using a knitting method to inlay materials into the connective layer which reinforces the structure of the fabric. The compression properties of three samples that were fabricated by inlaying three different types of silicone-based elastic tubes and one sample without inlaid material have been investigated. The mechanical properties of the elastic tubes were evaluated and their relationship to the compression properties of the inlaid spacer fabrics was analysed. The compression behaviour of the spacer fabrics at an initial compressive strain of 10% is not affected by the presence of the inlaid tubes. The Young's modulus of the inlaid tubes shows a correlation with fabric compression. Amongst the inlaid fabric samples, the spacer fabric inlaid with highly elastic silicone foam tubes can absorb more compression energy, while that inlaid with silicone tubes of higher tensile strength has higher compressive stiffness.

Preparation and characterization of polyurethane/soluble eggshell membrane nanofibers.

Superfine Particles (SP) of soluble eggshell membrane and medical grade polyurethane (MPU) blend nanofibers were prepared by electrospinning different blend ratios of SP/MPU suspensions for regeneration of the natural fiber-like structure of the eggshell membrane. The addition of SP had no obvious effect on the electrospinning process of MPU nanofibers, and the SP were randomly dispersed in the MPU nanofibers with no agglomeration of SP when the amount of SP was less than 20 wt%. Although the average diameter of the blend nanofibers is approximately 30% larger than that of the pure MPU nanofibers, they exhibit excellent tensile strength and tensile resilience that are close to those for pure MPU nanofibers. In addition, the blend nanofibers become fully hydrophilic, and the water contact angle of the blend nanofibers decreases dramatically to 0°. Therefore, with the advantages of a collagen ingredient and good hydrophilicity, these blend nanofibers are suitable for applications such as facial masks, wound dressings, and pharmaceutical carrier materials.

Effect of electron beam irradiation on the structure and properties of electrospun PLLA and PLLA/PDLA blend nanofibers.

Poly(L-lactide) (PLLA) and a PLLA/poly(D-lactide) (PDLA) blend (50/50 wt.%) were electrospun into nanofibers. Electron beam (e-beam) irradiation of the electrospun PLLA and blend nanofibers was used as a method to alter their structures and surface properties. The crystalline structures of the nanofibers before and after irradiation were investigated by differential scanning calorimetry. Tensile tests of the aligned nanofibers were also performed to determine the effects of irradiation on the mechanical properties of the nanofibers. The hydrophilicity of the nanofibers was determined by water contact angle measurements, while any degradation of the fibers caused by irradiation could be detected by intrinsic viscosity measurements. The e-beam irradiation method was able to improve the surface hydrophilicity of the PLLA and blend nanofibers, although bulk degradation was inevitable.

Carbon nanotube reinforced Bombyx mori silk nanofibers by the electrospinning process.

Nanocomposite fibers of Bombyx mori silk and single wall carbon nanotubes (SWNT) were produced by the electrospinning process. Regenerated silk fibroin dissolved in a dispersion of carbon nanotubes in formic acid was electrospun into nanofibers. The morphology, structure, and mechanical properties of the electrospun nanofibers were examined by field emission environmental scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and microtensile testing. TEM of the reinforced fibers shows that the single wall carbon nanotubes are embedded in the fibers. The mechanical properties of the SWNT reinforced fiber show an increase in Young's modulus up to 460% in comparison with the un-reinforced aligned fiber, but at the expense of the strength and strain to failure.