Wood’s main physical property: Density and hardness moisture shrinkage and swelling, what’s more, wood also has many flaws, like knot in common, twill, creaks, clips, poles etc. According to the properties, woods for packaging make rules:
1. The way to pick up the woods is not only to check the performance, but adequate supplies, cheap price, easy to process and non-special treatment.
2. Requirement of good cut resistance and nail holding power.
3. Clear request to moisture content: under 20%
4. Diagonal tilt below one-tenth, Burl wood wide in diameter one-third, parts of the nail and there should be no knot at both ends. For stress components of wood, its size must not exceed the thickness of the dull edge and bark with one-second, in sheet width direction shall not exceed 2cm. Cannot have more than 1.2cm knot holes in the plates, Poles, die section and leakage.