The purpose of this research was to find out which kind of dowel works better under tensile and bending strength. In this case, it is important to ensure combining strength and durability of various components forces. The dowel must be the exact diameter and the hole drilled in the best possible fit. To find out these tests results, the author had to work out how he could test the tensile and bending strength by eliminating outside factors. First, details from birch were made, then glued together using two different kind of dowels, sizes 8 x 40 mm and 10 x 40 mm. The test results of tensile strength showed that fluted birch dowel is to some extent better than a twisted dowel. The reason that smooth dowel is stronger is because the grooves are deeper and the glue between detail’s surface and dowel’s surface helps to bind their grains better. The test results of bending strength showed assuredly that a twisted dowel is stronger than a fluted dowel. This is caused by how they are made. In the process of making twisted dowels wood becomes denser as it is rolled through 3 rollers which create the grooves. The technology to make fluted dowels is much simpler. A milling machine just cuts the grooves into a stick. No high pressure is being used.
Keywords: wooden dowels, birch, tensile and bending strength analysis
Authors
Dobris J.
Faculty of Chemical and Materials Technology, Tallinn University of Technology, Tallinn
Luts A.
Wood Processing Technology, Võru County Vocational Training Centre, Väimela, Võru
Meier P.
Competence Centre, Võru County Vocational Training Centre, Väimela, Võru County
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