Silk Fibers

High stiffness and strength carbon fibres are commonly used to reinforce epoxy-resin composites. While wild Antheraea pernyi silk fibres exhibit high toughness originating from their α-helix/random coil conformation structures and their micro-fibre morphology, their insufficient strength and stiffness hinders them from being used in similar structural composites. In this work, we use interply hybridization of silk and carbon fibres to reinforce epoxy-matrix composites. With increased carbon fibre content, the quasi-static tensile/ flexural stiffness and strength increases following the rule of mixtures while more silk fibre acts to increase ductility and impact strength. This results in a composite comprising equal volumes of carbon and silk fibres achieving an impact strength of 98 kJ m −2 , which is twice that of purely carbon-fibre reinforced composites (44 kJ m −2). This work shows tough natural silk fibres and strong synthetic fibres can be successfully integrated into epoxy-resin composites for tailored mechanical properties.

The aim of this study was to synthesize glass ionomer-silk fiber composite and examining the effect of adding natural degummed silk fiber on the mechanical properties of glass ionomer cement (GIC). For this purpose, natural degummed silk fibers with 1 mm length and 13-16 µm diameter were added to the ceramic component of a commercial glass ionomer cement in 1, 3, and 5 wt. %. Compressive strength (CS), three-point flexural strength (FS) and diametral tensile strength (DTS) of the prepared glass ionomer-silk fiber were measured. Analysis of variance (ANOVA) was used to compare the obtained results. Moreover, SEM technique was used for the investigation of the surface morphology of the as-prepared composite and the fractured area. The results showed that the highest compressive strength, flexural strength and diametral tensile strength were obtained using 3, 3, and 5 wt. % of silk fiber, respectively. However, at 3 wt. % of silk fiber, all three measures of strength exhibited a significant increase compared to the commercial GIC. Therefore, it can be suggested that the addition of 3 wt. % silk fiber to the ceramic component of GIC is desired for dental restorations and orthopedic implant applications, where the maximum strength in all three modes of loading would be beneficial.

Silk fibres exhibit good biodegradability, biocompatibility and balanced strength and toughness, which are useful for toughness/impact-critical composites in the biomedical field. However, the impact of hydration has not been studied for silk fibre-reinforced polymers (SFRPs). In this work, SFRPs fabricated vacuum-assisted resin infusion (VARI) were treated under three hydration conditions. A hydration condition of 40 ◦C at 89% relative humidity (RH) was sufficient to induce a reduction in the tensile and flexural modulus and yield strength of SFRPs.Acoustic emission (AE) analysis showed that interface failure played a key role in the damage modes of SFRPs. Although mild hydration treatment appeared not to affect SFRPs, high hydration led to more susceptible interfacial failure. This work is intended to reveal the structural mechanisms of SRPPs under hydration, and to provide a useful reference for potential biomedical applications.

This paper is about mechanical properties in waste silk in silk related industries situated in the Dharmavaram is a city in Anantapur district of the Indian state of Andhra Pradesh. The city is famous for its handloom silk sarees. The city is renowned for cotton, silk weaving industries and leather puppets. Experiments were conducted under laboratory condition to assess the effect of different environment such as subzero, steam, saline water and natural conditions for various time lengths. The change in weight, volume and dimensions are studied for various treatments. Shear strength of the composites was evaluated by three point bend test as per ASTM standard. The increase the potential use of waste silk fiber, in the present study the erosion wear behavior of silk fiber and hybrid laminate composites with Jute and synthetic fiber glass have also been carried out. Dharmavaram region in Anantapur is world-famous for the handmade pure silk sarees. It’s a major hub for Silk trade with end to end silk related industries situated in the region supporting a major portion of population. silk manufacturing also wastes are generated during manufacturing. These wastes to some extent are used for manufacturing less delicate products such as sportswear, draperies and upholstery. In order to find value added application of this waste, the present work deals with preparation and characterization of epoxy composite with addition of waste silk fibers

There is an emerging interest in natural silkworm silks as alternative reinforcement for engineering composites. Here, we summarize the research on two common silkworm silks and silk fibre reinforced plastics (SFRPs) from the authors over the past few years in the context of related research. Silk fibres from silkworms display good strength and toughness under ambient and cryogenic conditions owing to their elastic-plastic deformation mechanism. In particular, the wild Antheraea pernyi (A. pernyi) silk also displays micro-and nano-fibrillation as an important mechanism for toughness and impact resistance. For SFRP composites, we found: (i) it is critical to achieve silk fibre volume fraction to above 50% for an optimal reinforcement and toughening effect; (ii) the tougher A. pernyi silks present a better reinforcement and toughening agent than B. mori silks; (iii) impact and toughness properties are advantageous properties of SFRPs; (iv) hybridization of natural silk with other fibres can further improve the mechanical performance and economics of SFRPs for engineering applications; and (v) the lightweight structure designs can improve the service efficiency of SFRPs for energy absorption. The understanding on the comprehensive mechanical properties and the toughening mechanisms of silks and silk fibre-reinforced polymer composites (SFRPs) could provide key insights into material design and applications.