Wood Filler-recycled Polypropylene (WF-RPP) Composite Pallet: Study of Fastening Method

Materials handling pallets were developed using wood filler-recycled polypropylene (WF-RPP) composite in our previous work. An important stage in the development of the full-size pallet is the assembly of the various components that make up the pallet. The objective of this work is to find a suitable fastening method, fastener type, and size to assemble the stringer- class pallet made from the composite. The following investigations were carried out: (i) comparative study on the ease of fastening screws with and without pre-drilling, (ii) determination of minimum depth to which pilot holes need to be drilled to enable screws of various sizes (# 3 to # 10) to penetrate into the composite, (iii) comparison on the ease of fastening the components using different screw types, (iv) determination of the minimum distance between screws and minimum distance of screw from the edge required to assemble the components without cracking, and (v) comparative study on the ease of fastening of composites having different filler loading. The results of the study showed that it is not possible to use wood screws or tapping screws to fasten the various parts of the pallet without pre-drilling. A pilot hole of diameter 2.5mm and depth more than 6.0mm was found to be suitable for screws with nominal sizes ranging from gauge # 3 (2.515 mm) to gauge # 8 (4.166 mm) to penetrate into the composite without difficulty.