pps proceeding - Abstract Preview
pps proceeding
Symposium: S04 - Functional, Nano and Bio Composites
Oral Presentation
 
 

Tailored Wood Strand Plastic Composites for High Performance Applications

Hartmann Robert (1)*, Koch Michael (1)

(1) Technische Universität Ilmenau - Thuringia - Germany

Processing of thin, oblong wood shavings (strands) is defined by the production of three-layered oriented strand boards (OSB). During the OSB manufacturing process, strands are wetted with a mixture of binder and additives in a large-volume drum, placed quasi-isotropic on a belt and are compacted in an open mold with specific conditions of temperature and pressure. Edge areas of OSB components have to be costly reworked and achievable mechanical properties are limited by the small proportion of strands that are aligned with significant load paths. Utilized binder systems for OSB are based on formaldehyde, which was classified as carcino- and mutagenic by the European Union in 2014. This publication introduces a high performance wood strand plastic composite material (WSPC), which compensates major disadvantages of OSB and enables the production of free-formed, load-conform, zero-waste and non-toxic lightweight components. Options for an automated WSPC production process were developed and requirements for suitable binder systems determined considering viscosity, adhesion and environmental compatibility. The behavior of strands when pressurized was investigated to specify the limit of the compression pressure which allows a maximum in mechanical characteristics while avoiding damage of the wood cell walls. Specimens were produced with an experimental mold by combining deliberately arranged strands with diverse formaldehyde-free thermoplastic and thermosetting matrices using resin injection and hot compression molding techniques. The measured density-specific bending strength parallel to wood fiber direction of a specimen compressed at 10 MPa and consisting of 10 wt-% polypropylene outperformed the reference sample made of OSB3 by 350 % and the comparative metallic sample made of aluminum alloy AlMg3F24 by 70 %. The proven lightweight potential and cost-effectiveness of WSPC are justifying its use for high performance applications in furniture, vehicles and construction.