Like the raw wood, wood material would be easier to bend if it contains a lot of moisture. There is an empty in the middle of the structure of the wood stuff which is composed of a slender cell. With a reinforcing bar, the arrangement of the cell would be described as concrete. The reinforcing bar of lies is usually of the cellulose (a high molecule that joined to each other as of a chain), which helps to crystallizes to form the microfibrillar, filled up to lignin affixed to the material.
With a view to perk up the imminence between the concrete and the reinforcing bar, the hemicellulose (a high molecule stay alive on the plane of the reinforcing bar) is placed. It takes almost no consequence of the temperature and moisture, as the microfibrillar is crystal stuff. But the lignin and the hemicelluloses become softer, causes the wall to be slacken enough, this is how to make the microfibrillar to be moved with no trouble. Under the above circumstances, we know that with the help of the method of boiling, steaming or the microwave, it will add to temperature of the material and the moisture content. This is how the bending course of action could be done without and difficulty.
Furthermore, so many more alteration might be done to the wood materials with the help of a press method contrast to the pulling technique. The wood substance with a moisture content of 17% breaks up when the bend is at about 5% when it is pressed or about 1% when it is pulled, in a room temperature. Nevertheless, it breaks when the warp is about 2% when it is pulled in the temperature of 100°C with 33% moisture, but do not split even the bend should be more than 35% during it is pushed. This put forward if we could hold using a pulling method and only uses a press to transform the material, and then it becomes feasible to bend till to a small diameter.
Therefore, for a small radius bending, if we join the strap and the wood material together during the bending or we put a fastening with a appropriate thickness to the expanding side of the material, means so that the pulling force would be wrapped up by the strip (Tip: the strap functions acts as an absorber by the force which is caused by the pulling action at the outer side), then we should be able to bend it devoid of breaking it. This method is known as “Tohnet’s Method”, this is also widely used now.
Special note: A lump sum calculation states that, we take for granted that the force produced by both materials are same at the contact surface, based on the young index of both the hardwood and the strap . Next, the thickness of the strap can be computed at about 1/10 of the thickness of the bended wood stuff. On the other hand, because of same wood material is not equal at all, this value is just for orientation. The extension quantity of the strap for steel and mild steel is completely different.