국산 대나무 OSB의 못 및 나사못 인발저항

Nail ＆ screw withdrawal resistance of OSB made from domestic bamboo

Bamboo is a fast-growing, economical, renewable, and processable material that has been shown to exhibit equal or better physical and mechanical properties compared to commercial wood species. But bamboo has very weak cleavage resistance. This study was carried out to examine the nail and screw withdrawal resistance of the OSB that was made from korean domestic bamboos. Bamboo strands were cut by laboratory disk type strander into the dimension of 50 mm in length, 7-8mm in width, and 0.5-0.7mm of thickness. Three layered strandboards were made using urea-formaldehyde resin content level of 12%, one percent of liquid paraffin wax emulsion, and one percent of ammonium chloride. The pressing temperature was 170℃, and pressing time was 5 minutes with target density of 0.75 g/㎤. The main objective of this work was to obtain basic data on the nail and screw withdrawal resistance of bamboo strandboard for processing. This information can be used in the manufacture of bamboo structural composite products and in other possible applications. Nail withdrawal resistance of bamboo strandboard showed not only 2∼3 times as high as that of pine, but also twice as high as that of pine with compensation for specific gravity. Screw withdrawal resistance of strandboard made from 3 months old bamboo was higher than those of PB and aspen OSB.(Bamboo Strandboard : 135.5kgf, PB:82.6kgf, aspen OSB: 78.1kgf) Three months old bamboo gave the highest of all. P. bambusoides exhibited higher nail and screw withdrawal resistance than P. pubescens