Thermoplastic Hybrid Composites with Wood Fibers: Bond Strength of Back-Injected Structures

Abstract

Due to their lightweight potential and good eco-balance, thermoplastic hybrid composites with natural fiber reinforcement have long been used in the automotive industry. A good alternative to natural fibers is wood fibers, which have similar properties but are also a single-material solution using domestic raw materials. However, there has been hardly any research into wood fibers in thermoplastic back-injected hybrid composites. This article compares the bond strength of an injection molded rib from polypropylene (PP) and wood fibers to different non-wovens. The non-wovens consisted of wood fibers (spruce) or alternatively natural fibers (kenaf, hemp), both with a polypropylene matrix. Pull-off and instrumented puncture impact tests show that, given similar parameters, the natural and wood-fiber-hybrid composites exhibit very similar trends in bond strength. Further tests using viscosity measurements, microscopy, and computed tomography confirm the results. Wood-fiber-reinforced thermoplastic hybrid composites can thus compete with the natural fiber composites in terms of their mechanical behavior and therefore present a good alternative in technical semi-structural applications.

Utilization of textile fabric waste as reinforcement for composite materials in car body applications: A review

“…The design of automobiles, their usefulness, and more economical construction, as well as lower fuel consumption, are the most important factors in choosing high-performance plastic materials over other materials used in automobiles. Every 10% reduction in vehicle weight is projected to result in a 5% to 7% reduction in fuel consumption [37][38][39][40][41][42]. (see in Figure 8) In recent years, global textile waste production by the apparel and textile sectors has reached millions of tons annually.…”