Investigation on the Bond Performance in Hybrid Wood-Plastic Components

Sustainable resource and energy management are essential aspects for the change of industrial products and processes of the coming years. The demand for resource-saving and sustainable products is increasing in many production areas. As a renewable resource with a wide range of properties, bio-based materials, such as wood, play a key role in this context. For the development of sustainable, lightweight as well as load-bearing structural components, the use of wood veneer shows great potential. Due to the microscopic structure of wood as cellulose fibers embedded in a lignin matrix, it is comparable to the structure of fiber-reinforced plastic semi-finished products such as tapes or organo sheets. In order to be able to serve a similar field of application as plastic-based semi-finished products, however, the wood-based product must meet the requirements in terms of functionalization, mechanical properties and process integration during production. One way to meet the specific conditions is to combine layered wood veneers together with plastic applications by means of wood-plastic hybrid components. The resulting plywood serves the function of bearing the load, while the plastic structure, e.g. ribs, ensures a sufficient stiffness of the part. Its structural integrity is mainly determined by the bond strength of the wood-plastic interface. The bond strength in turn depends on the type of plastic used, on the conditioning of the plywood and on the process parameters during overmoulding. In the context of this work, the bond strength between beech wood-veneers and different plastics polypropylene is investigated. Therefore, rib specimens are manufactured in an overmoulding process with varying parameters. Afterwards, the bond strength is determined in a rib pull-off test and the influence of the variation parameters is investigated.