In the process of flame-retardant board manufacturers, the force of the ruler through the blade of the rotary knife, reduce the veneer back crack, increase the transverse tensile strength of the veneer, and then improve the veneer finish.

There are three types of pressure scale: fixed pressure scale, roller pressure scale and heating pressure scale. Among them, the pressure distribution of the fixed ruler on the veneer is more concentrated, can make the veneer surface smooth, and when the veneer passes through the knife door, the friction resistance is small, the thin veneer is not easy to plug the knife door, suitable for rotary cutting hard wood and thin veneer; Roller ruler is made of stainless steel or other materials with bearing support at both ends, itself can be driven by the motor or by the rotation of wood friction drive, roller ruler press surface is large, the press degree is gradually increased, used for rotary cutting soft wood and thick veneer.

The heating ruler is a new type of ruler. In order to limit the heat conduction to the ruler frame, the bottom of the ruler is grooved to reduce the contact surface, and the surface of the ruler is chrome plated to increase the wear resistance.