Wood anti-mold treatment method

The proposal belongs to the technical field of anti-mold wood, and specifically relates to a method for anti-mold of wood, anti-mold wood and applications thereof. The anti-mildew method for wood provided by this solution includes the following steps: performing low-temperature treatment on wood to obtain low-temperature-treated wood; the temperature of the low-temperature treatment is -30-70°C; performing medium-temperature treatment on the low-temperature-treated wood to obtain secondary treatment Wood; cycle the low temperature treatment and the medium temperature treatment at least twice to obtain mildew-proof wood; the cycle starts from the low temperature treatment. The invention destroys the cell wall and cell membrane of the wood through low-temperature treatment, so that the nutrients in the cells leak out; through multiple low-temperature and medium-temperature alternate treatments, the nutrient source required for bacterial growth is eliminated, and the anti-mildew ability of the wood is improved. The anti-mildew method for wood provided by this scheme retains the color and structure of the log itself and has good environmental protection.

Wood mildew introduction:

The newly harvested wood is easy to mold if no proper protection measures are taken during transportation and storage, processing and use, which not only affects the appearance quality and reduces economic value, but also creates conditions for the invasion of other fungi. The fungi in the microorganisms mainly pollute the wood surface and have little effect on the weight and strength of the wood. Mold often occurs on wood together with other fungi, which makes it difficult to separate mold from decay and discoloration fungi. But because the thunder fungus reproduces very quickly, it often hinders the growth of other fungi. Thunder fungus invades wood mainly by absorbing sugar and starch in wood as a food source, without destroying the cell wall and having no effect on wood strength, but it can increase the permeability of wood. Mold can cause wood to form stains of various colors, and form gray, green, red-yellow, blue-green and other discolored mold spots on the wood surface. The reason why these fungi can cause spots is that the pigmented spores or hyphae accumulate on the wood surface, or the wood is polluted by the products of metabolism. These yellow, red, green and dark brown mildew spots are mostly attached to the wood surface. , usually can be removed with bleach, wire brush or fade after drying, but the mold grows for a long time, the stain will penetrate into the wood fiber, resulting in damage to the mechanical properties of the wood and reducing the strength of the wood.

Wood mildew is caused by microscopic fungi, which degrades wood and wood products, and in severe cases causes major economic losses. The quality standards of plywood, veneer, furniture and decorative wood products in my country have restrictions on blue stains and mildew, and export products require Stricter, mildew is not allowed. Foreign countries pay more attention to anti-blueing and anti-mildew. my country also pays more attention to the anti-blueing and anti-mildew treatment of rubber wood, bamboo and some export products. . With the implementation of natural forest protection projects, the further development and utilization of plantation wood and bamboo, and the changes in the wood market caused by joining the WTO, wood anti-blue stain and anti-mildew measures will become more important. The publication and implementation of the national standard CBT18621-2013 “Test Method for the Control Efficacy of Antifungal Agents on Wood Mold and Discoloration Fungus” has provided motivation for further research and development of new antifungal agents for humans. Just visible a lot of spore clusters, be black, also have light green: be black speckle on broadleaf wood surface. Most molds grow most vigorously when the relative humidity of the atmosphere is above 90%.

Some molds can occur on wood with a moisture content of 20%, so wood molds are more resistant to adverse conditions than wood rot fungi. The drug resistance of molds is also higher than that of decaying fungi. For example, preservative-treated pine (Pinus spp.) can prevent and control most wood-rotting fungi, but not only cannot prevent the growth of many molds, but can even stimulate the growth of molds. Many molds are also resistant to high temperatures. The harm of mold to the microstructure of needle and broad-leaved pine trees is similar to discoloration fungus. Under suitable conditions, it can also cause wood soft rot like discoloration fungus. Some molds have slight damage to wood cell walls. Mold and discoloration fungus mainly take polysaccharides in wood cells, and hyphae usually appear in many ray parenchyma cells. The penetration of hyphae is mainly through the fiber gap.

Wood mold inhibitor:

Agents for the control of wood mold and discoloration are collectively referred to as wood mold inhibitors. Halogenated phenols and their sodium salts (such as pentachlorophenol and sodium pentachlorophenate are the most commonly used fungicides in the past few decades. Since carcinogens were found in pentachlorophenol, many countries (regions) have completely banned or Limit the use of halophenol antifungal agents for wood in contact with the human body, and devote ourselves to the research and development of low-toxic antifungal agents, organic iodine (IPBC), chlorothalonil (chlorothalonil), quaternary ammonium salts (DDAC, BAC), triazoles, Quinoline (CU-8), naphthenate (copper naphthenate) anti-mildew and blue stain tests show that there is often a large distance between the results of indoor toxicity tests and practical applications, and field tests must be carried out to screen wood anti-fungal agents There are many types of molds, and the drug resistance changes greatly; the drug resistance of molds is often stronger than that of discoloration bacteria; the concentration of liquid medicines for the prevention and treatment of blue stains and molds of different tree species in different regions may not be exactly the same. In order to expand the broad-spectrum function of anti-fungal agents Sex, improve the bactericidal effect, also researched and developed many compound wood antifungal agents at home and abroad.

Introduction to several methods of wood mildew prevention:

According to the introduction of David from gzzxsc, a wood antifungal agent manufacturer, wood antifungal treatment methods can be treated by drying, sulfur fumigation, antifungal agent spraying, antifungal agent mixed with water, and antifungal agent mixed with water. Wood has anti-mildew resistance to avoid the erosion of wood by mold. Each wood processing factory, furniture factory or handicraft factory can choose different anti-mildew treatment methods according to the factory’s own situation.

1. Drying method to prevent wood moldy:

Wood is dried, and special equipment is used to heat-treat wood. Artificial conventional room (kiln) drying refers to the use of wood drying rooms (kilns) to dry wood. It can artificially control the drying conditions to dry the wood, referred to as room drying or kiln drying. At present, in the wood drying production at home and abroad, conventional room drying accounts for 85%-90% of the wood drying production. The heat source used is a steam heater, which needs to be equipped with a steam boiler. This method is costly. Although it can reduce the moisture content, it cannot fundamentally solve the problem. For example, the environment where the wood is stored has high humidity, and the wood will absorb moisture again, which will increase the humidity of the wood and cause mold. This method of wood mold prevention It is suitable for short-term storage of wood or seasonal storage with low humidity and temperature.

2. Sulfur fumigation method to prevent wood moldy:

In the beginning, sulfur fumigation was used to prevent mildew, corrosion and insects in wood, and the moisture content of wood was required to be greater than 5%. Sulfur fumigation is that sulfur vapor and water vapor can react to form sulfur dioxide, which is injected into wood fibers under normal pressure for about 25 minutes. Sulfur combustion will form sulfur dioxide, which will seriously exceed the standard. At the same time, sulfur contains heavy metals such as lead and mercury, which will also cause lead poisoning or mercury poisoning to the human body. Due to environmental protection requirements, this method of wood mold prevention is not recommended.

3. Spraying method to prevent wood mildew:

This method is suitable for the treatment of bamboo and wood boards. etc.) If soaked with anti-fungal agent, it will cause deformation, so you can use wood anti-fungal agent to spray on its surface, and directly consult the anti-fungal agent supplier to purchase fast-drying wood anti-fungal agent for treatment. For bamboo and wood board factories, The assembly line can be set up, and the antifungal agent automatic spraying equipment can be set up on the assembly line. When the machine senses that the plate passes by, the nozzle will automatically spray out the antifungal agent to cover the plate, and the drying equipment can be added at the rear end to dry it. This method can reduce the consumption of labor and medicine. If the dosage is small or it is inconvenient to set up a spray box, you can directly use a sprayer to spray evenly on the surface of the board or use a clean mop dipped in the agent to brush on the board.

4. Soaking method to prevent wood moldy:

In order to ensure the anti-mildew and insect-proof effects of bamboo, wood, rattan, grass and their products after treatment, soak the wood with the wood anti-fungal agent stock solution, and the weight of bamboo, wood, rattan, and grass should increase by 15%-20% (about 5-10 minutes). Remarks: The soaking liquid is prepared according to the ratio of 1:20 (5Kg wood antifungal agent: 100Kg water). Bamboo, wood, rattan, grass and their products are all immersed in the prepared liquid medicine (do not expose the water surface), and after reaching a weight gain of 15%-20%, increase or decrease the soaking time and weight gain according to the dry humidity of the bamboo wood, and then take out the drops Dried liquid medicine, air-dried or sun-dried and put into storage. Large-scale bamboo wood treatment requires the construction of a pool, which is convenient to use.

5. Vacuum pressure method to prevent wood mold:

The method is to place the wood in a vacuum container, and vacuum out the air in the wood cell cavity to form a negative pressure. Pour the wood antifungal agent solution into the container under vacuum conditions, and the pressure difference between the inside and outside of the cells will make the liquid enter the wood. The vacuum method has a good treatment effect and the equipment is relatively simple. Generally, it can be installed and used on large-scale ancient pavilions, promenades, and maintenance sites. Increase a certain pressure in a special airtight container, and inject the wood antifungal agent into the wood fiber pores. The effect of pressure treatment is better than that of other methods. The wood antifungal agent penetrates deeply and distributes evenly. Industrial production, large output, easy to achieve quality control, generally used for anti-mold and anti-corrosion treatment of bamboo and wood with high density and difficult penetration of chemicals. In order to ensure the quality of treated wood in large-scale and concentrated maintenance projects of ancient pavilions and promenades, smaller pressurized treatment tanks can also be installed as needed.