Bamboo veneer

The term veneer is commonly applied to any one of the thin layers or sheets of wood cut or sawed from a log, that are glued or otherwise bonded together to form plywood boards.

In the case of bamboo, there are several methods for obtaining different types of veneers. These methods are: rotary, sliced and sawed veneer, which requires special types of machinery, and two handmade methods for the manufacture of veneer using the external or internal part of the culm. This is rotary veneer, a type of bamboo used in the manufacture of non structural plybamboo and for overlaying inferior plywood with decorative purposes.

This veneer is peeled from round section of giant bamboos. Since the bamboo culm is hollow and the diameter and thickness of the wall decrease from the base to the top, it is only possible to manufacture bamboo rotary veneer from the sections of giant culms which include 1 to 3 internodes (about 50-60 cm long) with a minimum wall thickness of 10 mm.

These sections must be cut with a circular saw from the center part of the culm which has the longest internodes, leaving the two nodes at the opposite ends.The culm sections are boiled at 100 degrees C for about 3 hours to soften the material. According to Takeuchi (1968) this treatment produces a high quality veneer and decreases culms cracking.

After the sections are softened, the nodes at the opposite ends are removed and the cut is made at right angles. The final length of the section has to be the same as the lathe. Then they are fixed to a small rotary cutter which works at a speed of 30 to 40 rpm. Generally the veneer is 3-4 meters long, depending on the thickness of the culm wall. The bamboo is air dried or dried with hot air to about 12% moisture content. The pressing can be done in a cold or hot press.