1, soaking method.

At room temperature and pressure, the wood is soaked in a tank or pool containing preservative solution, and the wood is always below the liquid level.

The soaking time depends on the tree species, wood specifications, water content and type of pesticide, and the specific amount of pesticide retention and penetration shall prevail.

In order to improve the treatment effect, ultrasonic wave, heating device and surfactant can be set in the immersion solution to improve the permeability of wood.

Depending on the length of soaking time, soaking methods can be divided into instant soaking (a few seconds to a few minutes), short-term soaking (a few minutes to a few hours) and long-term soaking (a few hours to a month).

Suitable for veneer, remedial anti-corrosion treatment, and temporary wood.

2. Diffusion method.

According to the principle of molecular diffusion, with the aid of water in wood as the carrier of agent diffusion, the agent diffuses from high concentration to low concentration, and diffuses to the deep layer of wood.

As a result, the diffusion method of wood preservative treatment must have the following conditions: 1) small material moisture content is high enough, usually more than 35% ~ 40%, the best raw wood;

2) water-borne agent (diffusion type), high solubility, and slow curing;

3) High ambient temperature and humidity.

According to the operation process, the diffusion method can be divided into paste diffusion method, impregnation or spray diffusion method, band diffusion method, borehole diffusion method (or drop diffusion method), and double agent diffusion method.

The diffusion treatment equipment is less investment and the production process is simple.

Easy to be applied and popularized in the vast rural areas.

Similar to this method is the tree SAP replacement method.

3, hot and cold tank.

Use the principle of heat expansion and cold contraction, make the gas inside the wood heat expansion and cold contraction, produce pressure difference, so as to overcome the permeation resistance of the liquid, be about to heat the wood in the hot liquid.

Make small wood in the air expansion, part of the water also evaporated, wood internal pressure is higher than atmospheric pressure, air and water vapor to the external overflow, at this time, quickly placed in the wood in the cold liquid, wood quench, the air in the wood due to contraction negative pressure, cold liquid into the wood.

According to the treatment method and the configuration of the cold tank, it can be divided into double tank alternating method, single tank alternating method of hot and cold liquid and single tank cooling method.

Due to the low treatment efficiency (compared with the pressure method), the energy consumption per unit product is large.

Suitable for small batch wood preservative treatment.