Veneer is a wood-based material, there are thin sheets of wood with a thickness of 0.1 to 10 mm.

Veneer can be obtained in three ways - by peeling, planing or sawing.
The main area of ​​rotary cut veneer's application is the production of laminated glued materials such as plywood, wood laminates, bent glued products, etc.
Birch is considered the best breed for peeling, as it has the following advantages:

  • low displacement;
  • structure uniformity;
  • high strength.

Hardwood raw materials are harvested in logs. With a 16 cm diameter and more, the lengths of deciduous logs are 1.3 and 1.6 m and multiples thereof; with a 18 cm diameter and more, logs with a length of 1.91 can also be made; 2.23; 2.54 m and multiples of them.
The technological process for the production of rotary cut veneer includes the following operations:

  1. Delivery of raw materials to the warehouse;
  2. Hydrothermal treatment of raw materials;
  3. Cut logs into blocks;
  4. Debarking of raw materials;
  5. Block peeling;
  6. Cutting of veneer strips into format sheets and selection of lumpy veneer;
  7. Veneer drying;
  8. Sorting;
  9. Repair of veneer sheets and joining lump veneer into cut sheets.

Hydrothermal treatment of raw materials is a mandatory operation that allows to increase the wood plasticity. Without this operation, it is impossible to obtain high-quality veneer, it will crack during the peeling process.
The duration of the hydrothermal treatment depends on the breed, the size of the raw material, its initial temperature and humidity, as well as the temperature of the processing agent.
Hydrothermal treatment can be carried out in water (this operation is called boiling) or in a saturated steam environment (steaming). In the production of rotary cut veneer, boiling is usually used.
Most often, there are open or closed cooking tanks those are used for the hydrothermal treatment of raw materials by boiling.
Cut logs into blocks. The log is a round assortment, the length of which is a multiple of the length of the block. When bucking, the cuts must be made strictly perpendicular to the block axis. The formation of end chips and step cut is not allowed.
Debarking of raw materials can be carried out both on specially designed debarking machines and on a peeling machine.
Block peeling. Peeling is the process of cutting wood in a plane parallel to the direction of the fibers and perpendicular to their length. When peeling, the block is given a rotational motion, and the knife is given a straight-forward motion of the feed to the axis of the block rotation. The width of the resulting strip of veneer is equal to the length of the block, and the total length depends on the block diameter and the veneer thickness.
Cutting of veneer strips into format sheets is most often carried out using guillotine format shears. The use of a looping conveyor allows to create a buffer stock of veneer and reduce the length of the conveyor.
Veneer drying veneer. The most common veneer drying equipment is roller dryers, in which the veneer is moved in a stream of heated drying agent by paired rotating rollers. Roller dryers are continuous installations with forced multiple circulation of the drying agent.
Sorting. After drying, the veneer is sorted, that is, divided into groups taking into account the wood type, the size and quality of the veneer sheets.
Veneer intended for the subsequent production of general-purpose plywood from it is divided into 8 grades:
• five grades - for outer layers of plywood: E (elite), I, II, III, IV;
• three grades - for inner layers of plywood: 1, 2, 3.
Sorting is carried out depending on the presence of grade-forming wood defects in veneer sheets, which include: knots; fungal lesions; color changes; cracks, as well as processing defects, the main of which is the surface roughness.
Repair of veneer. The quality of veneer can be improved: a) by cutting down sections of the veneer strip containing unacceptable wood defects; b) by repairing formatted veneer sheets; c) by tightening of cracks with adhesive tape or staples.