Have been in the plywood industry for more than 9 years since 2004 ,visited so many plywood manufacturers’s production lines ,checked and inspected more hundreds of thousands of pieces of plywood and various different wood spieces and types of in personal .Found one good interested thing is how to increase or improve their plywood thickness without increasing costs :The major ways I found are below :
1.Reduce the pressure of the pressing machines
All the plywood must have passed the COLD PRESS AND HOT PRESS production process ,so ,the factories find a way to reduce the PRESSING RATE to make sure the plywood are not well pressed ,then the thickness of the plywood are a little thicker than normal plywood ,from the visual testing or apperance test ,the plywood are thicker than it was .So ,professional inspectors can test the density or weight of the plywood to test if the manufacturers use accurate pressing rate to make plywood .This can create not uniform thickness of the 4 sides of the plywood ,they found a way to make sure the 4 sides of the plywood thickness are uniform ,they put some materials on the shelves of the pressing machine ,to make sure the machine pressure can not press too heaviely.
2.Add one layer STRIP plywood core veneer around the circle of the plywood edges .
During the core construction lay-up ,they put one layer of thin strip plywood for each side of the plywood edges ,just outside edges .From the edges you can see how many layers core veneer they used .This method of increasing the plywood thickness normally can creat one quality problem ,the inside of the plywood thickness are a little thinner than the outside of the plywood thickness ,when you cut them to small pieces,you can find the outside layers thickness are ok ,the inside layers of the plywood thickness are much thinner than outside layers or edges .the inspectors can account the norma layers or plies of the core construction far away from the 4 corners of the plywood ,or edges . 11 plies or 12 plies …