How is the artificial dyed veneer processed?
Guide: There are two kinds of wood veneer used for surface veneer of wooden furniture products, one is natural wood veneer, and the other is artificial dyed wood veneer.
Natural bark is a kind of natural wood, which has natural texture and color without artificial modification; Dyed veneer is the veneer modified by artificial dyes.
Dyed wood veneer is generally based on natural wood veneer, which is obtained by using machine processing technology to change the color of natural wood veneer or repair defects; There are also some whole wood that has been dyed. We call it dyed wood. The wood bark made from this kind of dyed wood is also dyed wood bark.
As far as the market is concerned, the artificial dyed veneer has the following advantages: 1. The dyed veneer has the original touch and texture of the natural veneer, and is more ornamental than the natural veneer after processing. 2. After processing, all the original defects of natural wood will disappear, and natural defects such as wormhole and scab of natural wood will be eliminated during processing. This makes the surface more smooth and comfortable than that of natural wood. To sum up, the natural wood veneer is made of pure natural materials, its grain can not be changed, and it is more natural and beautiful, with a strong three-dimensional sense and artistic sense; Dyed wood veneer is said to be “from nature, better than nature”, and can even restore various rare wood, which can better meet the needs of different customers. There are different dyeing methods according to different uses of dyed materials. Veneer dyeing, solid wood dyeing and standing wood dyeing are commonly used. Veneer dyeing The so-called veneer dyeing refers to the uniform dyeing of peeled or planed veneer by immersion method. The veneer thickness is generally 0.2~1mm. The dyed veneer can be used as a component material of wood-based panel veneer, furniture veneer and artificial simulated wood. Taking the most common dyeing process of imitating rosewood veneer with acid dyes as an example, the process includes veneer decolorization → acid dye dye solution → fixation treatment → soaping → drying. Solid wood dyeing Solid wood dyeing refers to the surface and interior dyeing of solid wood. In the process of solid wood production, it is necessary to dye the interior of solid wood (the dyeing depth is more than 1cm). Due to the high thickness of solid wood, it is difficult for dye to penetrate under normal conditions, so it is necessary to use pressure decompression impregnation dyeing or cooking method to treat dyeing. Generally speaking, do not choose coniferous wood species with oil resin, such as masson pine and larch, and do not use tree species with developed wood infill, such as robinia pseudoacacia and quercus acutissima. If it is necessary to dye the tree species with poor wood permeability, the corresponding degrease must be extracted to eliminate the obstacles affecting fuel permeability. Standing dyeing The so-called standing dyeing refers to a method that uses the sap flow generated by sap transpiration as a natural driving force to disperse the dye to the dry part of the tree so as to dye the wood. Using this method, the dyeing speed is fast, and the dyed wood can see the dyeing state of the fine structure clearly, which can maintain sufficient brightness. This method uses the natural driving force of standing trees to save energy; At the same time, it can realize the whole tissue dyeing of small diameter wood of coniferous and hardwood. Not only does it not cover up the texture of the wood itself, but also highlights the sense of hierarchy of the wood surface; It can endow wood with colors that it does not have, so it is widely used in interior decoration, handicraft materials, etc. Factors affecting dyeing effect Among the factors affecting dyeing effect, the first one is the permeability of wood. Wood is a kind of heterogeneous capillary material. The fuel passes through the wood capillary channel with water solution, diffuses through the wood cell wall, and then settles on the fiber surface, making the wood stain. The permeability of wood is closely related to wood dyeing, especially the dyeing of wood interior. Generally speaking, the higher the permeability of wood itself, the better the permeability of its fuel inside the wood. The permeability of main wood in China can be divided into four grades: 1 The most difficult to penetrate tree species include coniferous wood such as larch, Chinese fir, paclitaxel, etc; Broad leaved wood such as black locust, sassafras, oak, etc. II The species that are difficult to penetrate include coniferous species such as Chinese fir, Huashan pine, Korean pine, etc; Broad leaved materials such as camphor wood, color wood, yellow pineapple, etc. III The species easy to penetrate include coniferous wood such as Pinus sylvestris var. mongolica, Abies liaotungensis, etc; Broad leaved wood such as locust, maple birch, etc. IV The most permeable tree species include coniferous wood such as Chinese pine, red pine, golden larch, masson pine (sapwood), etc; Broad leaved wood such as ash, aspen, birch, basswood, poplar, etc. The dyeing effect of wood is not only affected by the permeability of wood itself, but also related to the composition of dye solution and dyeing process parameters. Specifically, it is closely related to the moisture content, tree species, chemical composition and tissue structure of wood. 1. The ideal wood moisture content is 12%~15%; When the wood moisture content is 30%, the dyed wood has uneven phenomenon such as stain; When the moisture content is lower than 8%, the dye uptake decreases. 2. Wood species and their tissue structure The density of coniferous wood is low, the dyeing time is short, and the dyeing is uniform; The density of hardwood is high, the structure and texture of early and late wood are different, the dye solution is difficult to penetrate into the late wood, the dyeing time is long, and the effect is poor. The fiber structure of wood has a significant effect on the dyeing property of wood. The intercellular layer is mainly composed of lignin, and the cell wall is composed of lignocellulose and hemicellulose. Metabolic substances are deposited in the tumor like layer of the inner wall of the cell cavity. After being treated with colorants, they have different color reactions. 3. The higher the temperature, the better the dyeing effect. However, the temperature shall be determined according to the use of the product, wood species, material thickness and dye variety. 4. Dye tinting At present, there are 13 kinds of special fuels for wood dyeing in the domestic market, including boxwood, teak, black walnut, etc. When selecting dyes for dyeing, try to use a certain dye corresponding to the chromatography. According to performance, dyes can be divided into direct dyes, acid dyes, basic fuels, active fuels, etc. Because acid dyes have good permeability, light resistance and chemical property, strong binding ability with lignin, low price and complete chromatography, and the dyeing ability of cellulose is greatly improved after auxiliary, acid dyes are currently used most in wood dyeing.
