Wood slicer machines are the main equipment for the production of veneer and thin wood. If classified according to the direction of movement of the planing knife in relation to the horizontal plane, wood slicers can be divided into two categories: vertical and horizontal. Depending on whether the planing direction is perpendicular or parallel to the length of the wood fibre, slicers can be divided into horizontal and longitudinal slicers.
Comparison of slicer and veneer peeling machine
The modern slicer is only 1/3 of the size of the old planer, it is compact, light and easy to install and commission; it can produce veneer continuously, saving time in loading wood, and is highly productive; it works extremely smoothly and is almost inaudible.
The veneer peeling machine is also one of the main machines used to produce veneer. In a sense, rotary cutters are more widely used than slicers. Rotary cutting machines are divided into two categories: concentric and eccentric, according to whether the wood section rotates around its own axis. Concentric rotary cutting machines are divided into spindle veneer peeling machines and spindle less rotary cutting machines. Eccentric rotary cutting can obtain beautiful radial pattern, but the productivity is lower than concentric rotary cutting.
Comparison of peeled veneer and sliced veneer
Veneer processing is an important process in the production of plywood, veneer laminated lumber (LVL) and other man-made panels. The two main methods of veneer processing are rotary cutting and slicing, and the corresponding processed veneer is called rotary cut veneer and sliced veneer.
The thickness of rotary cut veneer and sliced veneer depends on the technical parameters of the respective machines. The thickness of rotary cut veneer in China is about 0.25 to 5.5mm, while the thickness of veneer cut by special purpose rotary cutting machines abroad can be up to 12mm. The thickness of sliced veneer also varies widely from 0.2 to 10mm. At present, the thickness of veneer made by veneer peeling machines is mostly above 1mm and below 3mm. This range of veneer thickness uniformity is better, for the production of plywood in the process of sizing and other processes convenient, not easy to glue through. The width of the veneer is large and has a beautiful chordal pattern. Nowadays, as people’s living standards improve, their requirements for quality of life are becoming higher and higher. In order to make full use of quality wood, veneer (also called thin wood) is now mostly made by slicing. Sliced thin veneer texture is beautiful and realistic, suitable for making parquet patterns, plywood and furniture and building pieces of veneer, etc.
Sliced veneer has the following advantages that make it so popular. Sliced veneer not only has the chordal grain of rotary cut veneer, but also has a beautiful, generous, natural wood feel that rotary cut veneer does not have. It also has a radial grain and a radius grain with minimal shrinkage. Because the longitudinal planing is along the length of the wood fibre, the cracking of the veneer caused by transverse planing is avoided and the planed veneer, therefore it has a higher transverse tensile strength than the rotary cut veneer. Back cracks and face cracks are almost non-existent. Not only is the thickness of the veneer uniform, but the finish is so good that it can be directly decorated with high-grade veneer without sanding, thus improving the strength and surface quality of the veneer. Compared to sawn and rotary cut veneer, the thickness of sliced veneer is easier to reach below 0.2mm. This facilitates the development of microwoods and allows for more efficient use of precious and rare woods, expanding the area of precious and high-quality woods.
Rotary cut veneer is generally used for the production of plywood and veneer laminates. Sliced veneer is generally very thin and can be laminated on the surface of chipboard, MDF and plywood. It is the main material for high-grade furniture, musical instruments and architectural decoration, as well as the main material for the secondary processing of wood-based panels. Both rotary cut veneer and sliced veneer can be used as decorative materials, and are generally available in both diameter-cut and string-cut grain. However, the diameter-cut wood grain is more acceptable than the string-cut wood grain. With the maturity of veneer production technology, it has been widely used in the construction, furniture and vehicle and boat manufacturing industries. The use of thick veneers for veneer laminates is advantageous for both the production process and cost reduction. Due to the increased thickness of the veneer, such as the production of the same thick solid degree of LvL, the number of layers of veneer can be reduced, thereby reducing the amount of veneer glue, reducing environmental pollution. In addition, the time for pre-pressing, hot pressing and forming blanks is greatly reduced, increasing productivity. In Japan, Kishita Suyuki and others have done more useful tests and research on thick veneer spinning. The thickness of the veneer cut in the test was 10mm and the quality of the cut was good. There is little research on thick veneer planing. According to German researchers, some species of veneer can be cut up to 15mm thick.
Ways to improve the quality of sliced veneer and rotary cut veneer
Ways to improve the quality of sliced veneer
1.Change the cutting motion of the planer so that the tool does an oblique up and down reciprocating motion relative to the direction of the wood fibres. The actual (working) wedge angle of the knife edge becomes smaller, the cutting resistance is reduced, the impact is not large, the planing is light and fast, and the quality of the thin board can be improved.
2.When the wood rays are not developed, planing wood should be cut with the annual cycle. When the wood ray is developed, should be counter-annual planing.
3.into the knife, the use of beveled edge cutting, reduce the vibration of the planer and veneer tear, thereby improving the quality of veneer.
4.The material of the cutter must be of a certain hardness and toughness. The grinding angle of the tool should be different depending on the tree species. In addition, the shape of the tool, the relative position of the tool and the pressure ruler also have a great influence on the quality.
Ways to improve the quality of rotary cut veneer
1.Master the steaming temperature of the wood section.
2.When using low alloy tool steel knives, the surface must be treated to improve the hardness and toughness required for the knives during rotary cutting. Ensure that the wedge angle, back angle and edge sharpness of the knives are as sharp as required. In addition, the press rate of the inner and outer veneer and the species itself are also important factors.