CONTRIBUTION OF SPINDLE-LESS ROTARY LATHE AND ITS EFFECT ON THE YIELD OF PEELED VENEERS AT PT. RIMBA RAYA LESTARI, KUTAI KARTANEGARA, EAST KALIMANTAN OF INDONESIA

Abstract

Rotary veneer peeling lathes with large spindles are widely used in veneer and plywood manufacturing plants in Indonesia. On average, half of the raw material logs become waste and 25% is contributed by the rotary lathe. Meanwhile, on the other hand, the world's demand for plywood products will never disappear, even will continue to rise. This is because plywood is one of the most environmentally friendly building material products deriving from renewable natural resources. With the regrowth of the plywood industry as in its former heyday, the demand for log raw materials will also increase in line with the potential for loss of logs as waste. In this regard, there must be fundamental changes in this industry, including the change in production machines from large rotary spindles to spindle-less. The purpose is to analyze its contribution to increasing the peeled veneer yield or volume. Furthermore, it aims to find out the volume of by-products, log-core, and spur-knife waste. The difference in results between the two types of lathes (spindle and spindle-less rotary lathes) was also tested. This study used a 3 x 2 x 5 factorial experimental design, with three factors or fixed variables: Quality, Diameter Range of Raw Material Logs, and Types of Rotary Lathe. Based on the analysis of the results of the calculations, in general, the spindle-less rotary lathe provided a yield of more than 60% of the raw material logs peeled off into veneers, in the form of continuous/endless veneers and poly piece core/odd veneers, in all quality and diameter classes, and the rest was waste in the form of round-up veneer and log-core by 15% with an average diameter of 23 cm. If the peeling was continued to a diameter of 7 cm, this would increase the veneer yield by more than 10%. The statistical analysis showed that only the factor of different types of rotary lathe had a nearly significant effect on the yield of the peeled veneer. The interaction of the three factors tested also had a very significant effect on the yield of the peeled veneer.

Keywords

• spindle-less rotary lathe
• veneer
• yield