In this study, various wood material sources were used for the manufacture of wood-polymer composites (WPC). The materials were categorised as virgin wood particles (VWP), reprocessed WPC particles (RWP) and recycled thermoset composite particles (RCP) and derived from two virgin wood sources, three-layer particleboards, medium-density fibreboards (MDF) boards, or two different wood/polypropylene composites. All produced wood-polypropylene compounds contained 60% wood material and were manufactured using a co-rotating extruder. Malleated polypropylene was used as a coupling agent. Specimens were injection moulded and subsequently tested for their physico-mechanical properties. To characterize particles before and after processing, dynamic image analysis (DIA) measurement were performed. Additionally, X-ray micro-computed tomography (XµCT) was used to characterize the internal structure of the composites and to verify the obtained particle’s characteristics. It was found that length and aspect ratio of particles were remarkably different before and after processing (loss in length of 15–70% and aspect ratio of 10–40%). Moreover, there were notably differences between the particle sources (RCP retained the highest length and aspect ratio values, followed by VWP and RWP). The results suggest that increased aspect ratios can indeed significantly improve mechanical properties (up to 300% increase in impact bending strength and 75% increase in tensile strength, comparing WPC based either on virgin spruce or MDF material). This phenomenon is suggested to be partially superimposed by improved dispersion of particles, which is expected due to lower variance and increased mechanical properties of RWP composites. However, no notable alterations were observed for composite density. Reprocessed WPC and, particularly, RCP material have proved to be an appealing raw material substitute for the manufacturing of wood–polymer composites.
A technological approach to the analysis of wooden artefacts from stone-tool using cultures remains underdeveloped relative to technologies from other materials such as stone and bone. However, in recent years archaeologists have begun to approach wood assemblages in a systematic manner, including macro- and micro-analyses of traces, and conducting experiments to build reference samples on manufacturing, use and taphonomy. However, there is as yet a lack of established nomenclature that would facilitate intra-site comparisons. Therefore, this glossary and associated code is a first step to initiate a synthesis and standardisation of analytical terms for early wood technologies from stone-tool cultures. An agreement and clear definition of terms is useful to avoid confusion and overlaps pertaining to all phases that help us understand the biography of wooded artefacts. This glossary and code relies both on the collective expertise of the authors as well as on existing publications, particularly those reflecting recent systematic analyses and descriptions of wood technologies and traces from stone-tool using cultures. As a work in progress, we hope to collaborate and communicate with others working on archaeological wood, particularly pertaining to assemblages from stone-tool using cultures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.