[Modification purpose]
Wood modification is a physical or (and) chemical processing method to improve or change the physical, mechanical, chemical properties and structural characteristics of wood. Its purpose is to improve the natural decay (worm) resistance, acid resistance, alkali resistance, flame retardancy, wear resistance, color stability, mechanical strength and dimensional stability of wood. Modified wood is called modified wood or improved wood. As for wood that has been treated with protective materials, plywood, particleboard, etc., although they have some properties of modified wood, they are usually not included in the category of modified wood.
[Modification technology]
Wood modification technology includes: wood plasticization, wood impregnation, wood acetylation, wood heat treatment, wood compression and bending, wood bleaching and dyeing, and other modification technologies.
[Common methods]
Currently, the main processes for wood modification by liquid medicine method are atmospheric pressure impregnation, high pressure impregnation in a closed container, vacuum impregnation in a closed container, and a combination of vacuum impregnation and high pressure impregnation. In these processes, the pressure around the wood is the same, the impregnation process is slow, and the production efficiency is low. To address the above problems, our company has developed a vacuum liquid pressure impregnation equipment. This equipment uses a liquid injection plate to inject liquid into one end of the log, and the liquid flows along the fiber duct or other capillaries to the other end of the log, displacing the free water in the log. At the same time, the liquid penetrates into the fiber wall to achieve the purpose of rapid impregnation.
However, this process has the disadvantages of liquid leakage from the log knots, or uneven pressure inside the log due to the presence of large knots, which may cause the log to crack. At present, the wood drying process mainly heats the surface wood and heats it up internally through heat conduction. Wood itself is a poor conductor of heat, and the heat transfer rate is low, which affects production efficiency.
