The following information comes from, 8035 Wood Industry Network - the big timber market that never ends
Veneer processing is the production of man-made panels such as plywood and laminated veneer lumber (LVL). Important process. Currently, the two main methods of veneer processing at home and abroad are rotary cutting and planing. The corresponding processed veneers are called rotary cutting veneers and planing veneers.
The thickness of rotary cut veneer and planed veneer depends on the process technical parameters of the respective machines. The thickness of rotary-cut veneers in our country is about 0.25~5.5mm. The thickness of rotary-cut veneers by foreign special-purpose rotary cutting machines can reach up to 12mm; the thickness of planed veneers also has a wide range of variation, which is 0.2 ~lOmm.
At present, the thickness of veneers produced by rotary cutting machines is mostly above 1mm and below 3mm. The thickness uniformity of veneers in this range is good, which is convenient and difficult for gluing and other processes in the production of plywood. Through glue. The peeled veneer is large in format and has a beautiful chordal pattern.
Now, with the improvement of people's living standards, people's requirements for the quality of life are also getting higher and higher. In order to make full use of high-quality wood, veneers (also known as thin wood) are currently produced by planing. The texture of the sliced ??thin veneer is beautiful and lifelike, and it is suitable for making parquet patterns, plywood, veneers for furniture and building parts, etc.
Sliced ??veneer (veneer) has the following advantages and is very popular: ① Sliced ??veneer not only has the chordwise texture of rotary cut veneer, but also has the beauty and elegance that rotary cut veneer does not have. , the most realistic radial texture of natural wood and the smallest shrinkage rate. ② Since longitudinal slicing is along the length of the wood fiber, veneer cracks caused by transverse slicing are avoided. Sliced ??veneers have higher transverse tensile strength than rotary-cut veneers, and there are almost no back cracks or surface cracks. Not only the thickness is uniform, but also the smoothness is very good. It can be directly decorated with high-grade veneers without sanding, thereby improving the strength and surface quality of the veneer. ③ Compared with sawing and rotary cutting veneers, the thickness of planed veneers is easier to reach less than 0.2mm, which facilitates the development of thin wood, can more effectively utilize precious and rare wood, and expand the use area of ??precious and high-quality wood.
Rotary cut veneer is generally used to produce plywood and laminated veneer lumber; while sliced ??veneer is generally very thin and can be used on the surface of particleboard, medium density fiberboard and plywood. It is the main material for high-end furniture, musical instruments and architectural decoration, and is also the main material for surface pasting of secondary processing of wooden artificial panels. Both rotary-cut veneers and planed veneers can be used as decorative materials. Generally, there are two types: diameter-cut wood grain and chord-cut wood grain. However, diameter-cut wood grain is more acceptable than chord-cut wood grain. With the maturity of laminated veneer lumber production technology, it has been widely used in construction, furniture, vehicle and ship manufacturing and other industries. Using thick veneers to manufacture laminated veneer lumber is beneficial to the production process and cost reduction. Due to the increase in the thickness of the veneer, if LvL is produced with the same thickness and solidity, the number of layers of the veneer can be reduced, thereby reducing the amount of glue applied on the veneer and reducing environmental pollution (according to surveys, most of the Glue is harmful to the human body). In addition, the time for pre-pressing, hot pressing, billet assembly, etc. is greatly reduced, improving productivity.
Japanese Kinoshita Suyuki and others have done useful experiments and research on thick veneer peeling. In the test, the thickness of the veneer peeling was 10mm, and the peeling quality was good. There is little research on cutting thick veneers. According to German researchers, some tree species can cut veneers as thick as 15mm.