Sandwich‐structured light‐transmitting composites based on waste textiles: Fabrication, optical properties, and bending failure behavior

Abstract Currently, glass fiber‐reinforced resin composites, as an advanced optically transparent material, have garnered widespread attention and research. In the context of new‐era developments, there is a growing demand and expectation for the visual artistic expression of light‐transmitting composites. In this study, glass fiber fabric, silk fabric, and recycled polyester jacquard fabric were used as reinforcement materials, while epoxy resin was selected as the matrix material. A green decorative light‐transmitting composite with uniform light diffusion and soft light effects was prepared using the vacuum bag molding process. By altering the woven structure (plain weave, twill weave, satin weave), yarn density, and yarn twist of the silk fabric, the optical properties of the composites can be regulated. The unique triangular cross‐section, woven structure, and large folds of the plain‐woven silk fabric were particularly conducive to the reflection and refraction of light within the composite, thereby significantly enhancing the uniform light diffusion and soft light properties of the material. Furthermore, the bending failure behavior of the composites was investigated through three‐point bending tests, acoustic emission (AE) test, and micro‐computed tomography (Micro‐CT) scanning. The laminate specimens reinforced with plain‐woven silk fabric exhibited the best bending performance, with bending strength and modulus reaching 434.4 MPa and 19.0 GPa, respectively. The combination of AE and micro‐CT scanning techniques successfully established the correlation between AE signals and damage modes. This study identified the main failure modes for plain woven, twill woven, and satin woven silk reinforced composites as fiber breakage, interlayer delamination, and fiber/resin debonding, respectively. Highlights Waste textiles were recycled for use in transparent composites. Silk fabric's weave structure affected composites' optical properties. Fiber breakage was the main failure in bending of plain woven composites. Plain woven composites exhibited optimal diffuse light, superior flexural performance.