odd number of plies or even number of plies of the chinese plywood ?
Visited one plywood factory ,found that they were using even number of plies for their chinese plywood ?18mm is just 10 plies ,normally 11 plies or 13 plies .But the quality is good without warpping and shrinking .
Also tried to find more factories like this factory,in the location closed to the factories ,most of them using even number of plies for theirplywood ?
Do you know where is the location ?
Plywood is made from thin layers of wood grain, glued together into a sheet of consistent thickness. The plies in plywood sheeting serve specific purposes and are arranged to maintain the integrity of the plywood by minimizing shrinkage and warping. Sheets are built from the bottom up, with each layer glued to the one below.
The front and back ply of each sheet of plywood are known as the back and the face. Both are aligned with the grain running with the length of the sheet. The front face is typically made from the best material, designed to be mounted face out, while the back will be of lesser material, designed to be hidden. The one exception to this rule is hardwood cabinet grade plywood, which has two smooth sanded faces, both suitable for finishing.
Plywood is always made with an odd number of plies, the minimum number being three. The thicker and better the quality of the plywood, the more plies it will have. The odd number plies, including both outside plies, are always aligned with the grain running vertical or length-wise with the panel. This is consistent throughout the thickness of the sheet, no matter the grade of plywood.
Even numbered plies are aligned perpendicular to the face and back plies with their grain running the width of the panel, or horizontal. This cross-grain positioning helps to prevent permanent warping and minimizes the effects of swelling and contraction that occur due to changes of temperature and humidity. As with the odd numbered plies, this is consistent throughout all standard plywood and adds greatly to its structural integrity.