Ways to increase the yield of sliced ​​thin wood

Due to the lack of precious wood resources that are widely loved and expensive, the production of precious wood is often processed into thin wood as a finishing material, which can save precious wood and provide high-grade wood decoration effect. To this end, improving the yield of sliced ​​thin wood is an important way for enterprises to increase production and improve economic efficiency. This paper discusses the ways to increase the yield of thin wood.

1.1 Prevention of discoloration and decay of logs

For decorative thin wood, the appearance quality is its most important indicator, and the quality of the logs, especially the discoloration is crucial to the quality of the sliced ​​wood. Customers often refuse to accept the discolored wood. Severe discoloration and even decaying logs can only be used for other purposes. In severe cases, they should be disposed of as waste materials. Logs are generally piled up under the same conditions. If a log is heavily discolored or decayed, most of the logs (especially the logs of the heart) will change color or decay. The yield of sliced ​​thin wood is calculated based on the total volume of logs. Therefore, effectively preventing wood discoloration is an important way to increase the total yield of logs. The causes of wood discoloration can be divided into two categories: one is chemical discoloration, including tannin discoloration and oxidative discoloration; the other is fungal discoloration, including mildew and blue (also known as cyanosis, sapwood discoloration). Generally speaking, wood discoloration refers to the discoloration of fungi, and the impact is more serious. Since wood mold changes only the surface of the wood is discolored and the depth of discoloration is shallow, it can be removed by a brush or it can be removed by shaving the surface layer. Mildew has little effect on the quality of the wood itself and is therefore generally not considered a defect. However, when the mold infects the wood, it can increase the permeability of the liquid to the wood, thereby promoting the formation of blue. Wood blue change usually refers to the discoloration of all sapwoods appearing in wood. Blue change is a general term for the discoloration of wood sapwood. In addition to blue change, it also includes other colors such as black, pink and green. Logs after harvesting should be sawed and processed as soon as possible. If it cannot be processed in time, it should be treated with anti-blue.

1.2 Prevention and control of wood blue and mildew

Anti-blue/mildew treatment can be applied to the end of the log and the bark peeling off to prevent the fungus from invading the wood. Most enterprises control the moisture content of logs to prevent the breeding of fungi, that is, stacking logs, spraying them together, increasing the moisture content of logs to make them higher than the moisture content of fungi, and controlling fungi to pollute logs. This method is most effective. The lowest cost. In addition, the log yard of the open-air stacking in summer should be equipped with a black sun protection awning to prevent the evaporation of the water from the upper logs too fast. Sodium pentachlorophenolate (NaPCP) has been used as an anti-blue and mildew agent in the past 50 years, but it has been gradually banned in more and more countries since the discovery of chlorinated phenolic compounds containing carcinogenic dioxin compounds. At present, new compounds that are generally accepted in most countries include: thiocyanatomethylbenzothiazole (TCMTB); methylidene dithiophenate (MBT); 3-iodo-2-propynyl butyl amide (IPBC); quaternary ammonium salts, such as dimercaptodimethylammonium chloride (DDAC); octahydroxyquinoline copper; triazole compounds, such as azaconazle, hexaconzole; chlorothalonil, etc. [2].

2 Planed wood products

2..1 The truncation of the log is 1220mm×2440mm due to the size of the veneer. Consider leaving a small amount of machining allowance and cut the log into a length of (2.60±0.05) m. The first kerf of the log is critical to the rate of thin wood [3]. For logs with a total length of (10+0.2)m, it can be sawed into 4 sections, each section taking 2.50~2.53m (the chain sawing saw has a sawing width of about 3cm and a total of 3 kerfs), which can improve The yield of wood.

2.2 Wood sawing According to the requirements of the splitting process, the saw is cut into wood on the sports car band saw. Different sawing solutions directly affect the yield of thin wood. According to the research, it is more reasonable to use the "three-open" method for the large-hearted logs of 30-50 cm diameter (referring to the logs with the core material area accounting for more than 40% of the entire cross-section) [4]. The sawing method is shown in Figure 1. Fig.1 Schematic diagram of the sawing road of the three-opening method Fig.1 Three-divisionradialsawingmethodforlogs2.3 After the cutting, the angled material of the core plate is the remaining residual plate after the partial cutting (refers to the wood cutting to the last remaining thin plate) ), the sliced ​​surface can be cut after being cut at a certain angle, thereby increasing the yield of the thin wood. The angle is generally 20 to 30°, and it is necessary to use a scribing saw to accurately cut. The cutaway schematic is shown in Figure 2 (the dotted line is the sawing path). Figure 2 Schematic diagram of the cut Fig.2 Sawingmethodforthecore

3 The purpose of steam cooking is to soften the wood, increase the plasticity and moisture content of the wood, and remove the extracts such as tannin from some woods [5]. Care should be taken to reduce the cracking of the wood during the softening process, otherwise effective cutting will not be possible. The wood is first sorted and sorted according to the size of the wood. The wood of similar size and tree type can be cooked together. Before cooking, the wooden heartwood faces are opposite each other and tied with galvanized iron wire. Practice has proved that the wood that is bundled at the same time and at the same time will hardly crack when cooking; if it is only bundled at both ends of the wood, the individual wood will crack; if it is not bundled, it will be directly cooked. There is more cracking in the wood. Therefore, the method of bundling the ends and the middle of the wood should be advocated. After the bundled wooden hoist is hoisted into the cooking pot, the height of the wood between the same layer should be consistent, the layer should be compacted between the layers, and the top layer of the wood should be pressed with a horizontal pressure bar to prevent the wood from being It floats during the cooking process, causing the top and bottom surfaces of the top wood to be unevenly heated and cracked. It is best to use a concrete cooking pool to soften the wood. If an iron cooking pot is used, when the boiled water is softened, the iron ions will dissolve in the hot water and contact with the wood to cause contamination of the wood. Therefore, the iron pot should be treated regularly, such as with ethylenediaminetetraacetic acid and The epoxy resin is periodically applied to the inside of the iron pot, and a chelating agent (such as ethylenediaminetetraacetic acid) capable of rapidly reacting with iron ions and capturing iron ions may be previously placed in the hot water. The use of a scientific wood cooking process is essential to reduce cracking of the wood. The rate of temperature rise is the main cooking process parameter and should vary depending on the specific tree species and the initial moisture content of the wood. Usually: 1 wood must be soaked in room temperature water for a certain period of time (generally 12h or more); 2 heating rate should be uniform, the temperature rise should be controlled at about 10 °C / h; 3 different tree species have different heat preservation temperature: some southern species (such as teak) planed wood can take 50 ~ 60 ° C, eucalyptus can take about 90 ° C; 4 holding time should be moderate, usually 40 ~ 50h.

4 Reasonable planing wood and shearing wood generally thin wood thickness 0.20mm, tolerance is ± 0.02mm. Under the premise of ensuring the quality of the thin wood, the cutting thickness can be 0.18mm or 0.19mm, so that one thin wood can be added after every 18 or 19 sheets. That is, if a wooden side can cut 1800 sheets or 1900 sheets of thin wood when the thickness is not adjusted, 100 sheets of thin wood can be added after adjustment. During the cutting process, the edge of the planer should always be sharp. The edge should be polished with oil stone to ensure the quality of the sliced ​​wood. In addition, the knife door should be cleaned at any time to remove the blockage. The cutting angle β of the cutting edge is generally 21 to 26° during the cutting; the relief angle is generally 0.5 to 2.5°; the inclination angle θ between the wooden side and the cutting edge is generally 25 to 30° for the coniferous tree, and the broadleaf tree material Take 10 to 15 °. Thin wood cutting should be carried out on the trimming machine according to the process requirements. It is necessary to avoid unevenness on both sides, inconsistent width and size of the head to improve the yield of the thin wood.

We provide all types of Kids Hanger in different materials, sizes, and colors. Perfectly sized are available in just the right size for children of all ages.The best wood make the hangers keep baby and infant garments from slipping off. Notches near the end of the arms to hold hanging straps securely. Beautiful colors and lovely design looks so cute. They are an elegant and affordable option to protect and pamper your finest children's clothing.

  • Made from solid wood, metal, plastic, etc.
  • Colorful and lovely looks
  • Customized design available

Children's Clothes Hangers

Kids Hanger, Baby Clothes Hanger, Kids Clothes Hanger, Childrens Hangers

EISHO CO.,LTD , https://www.eishohome.com