Following are the main steps of plywood manufacturing process.
- Selection of Log
- Layer Formation
- Exposure to Heat
A brief description of these steps is discussed below.
Selection of Log
The first step is the selection of a good log from selected tree wood according to the demand of the type of plywood to be manufactured. This log is known as peeler. Peeler is straight and has a good diameter as large number of layers are expected to make from it.
The large blade is used for the processing of thin layers inside sawmill and made sheets of veneers. A horizontal placement of log under blade is maintained to get a better result. Continuously blade is pressed and several layers are cut into pieces.
Exposure to Heat
The sheets are then exposed to heat for removing water content from those. An good dehydration of sheets is confirmed before next step.
After drying the sheets those are glued together maintaining the system of a different type of plywood. In this step, caution is maintained to get the best result. After patching and grading this gluing takes place. urea formaldehyde and phenol formaldehyde is used for gluing. And Furmecyclox is used for fungal resistance quality.
The glued plywood primary sheets are sent for baking and pressing at required temperature and pressure. The minimum temperature is 140 degree Celsius and pressure is 1.9 MegaPascal.
Finally, defects of manufactured plywood sheets are solved. Holes, pits or any unfinished edges are given finishing. Also resizing, reshaping takes place.