Pretreatment method for improving dimension stability of timber

A dimensional stability and pretreatment technology, applied in impregnated wood, wood impregnation, wood processing utensils, etc., can solve problems such as deformation and cracking, achieve the effects of reducing heat treatment temperature, improving hydrophilicity, and saving energy

Inactive Publication Date: 2011-11-16
NORTHWEST A & F UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the problems and deficiencies in the above-mentioned prior art, the object of the present invention is to provide a pretreatment method for improving the dimensional stability of wood, which overcomes the tendency of wood to change with the temperature and humidity of the surrounding environment during use. Defects such as deformation and cracking make the treated wood products have good dimensional stability

Method used

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  • Pretreatment method for improving dimension stability of timber

Examples

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Effect test

Embodiment 1

[0022] Soak poplar wood with a thickness of 20 mm, a width of 100 mm, and a length of 1000 mm in 20% aqueous glycerin solution at room temperature and pressure for 24 hours, take out the test material, and air-dry to reduce the moisture content of the wood to 10%. Put the wood into the heat treatment box, turn on the water vapor switch, rapidly raise it to 140 °C at a speed of 10 °C / h, keep it warm for 30 minutes, and dry the wood at high temperature to reduce the moisture content inside the wood to 0; raise the temperature to 160°C, keep the heat treatment for 5 hours; turn off the water vapor switch, reduce the temperature of the heat treatment box, when the temperature of the heat treatment box drops below 80°C, turn on the water vapor switch, adjust the moisture content of the wood to 7%, and remove the wood.

Embodiment 2

[0024] Soak poplar wood with a thickness of 30 mm, a width of 100 mm, and a length of 1000 mm in 30% aqueous glycerin solution for 36 hours at normal temperature and pressure, take out the test material, and air-dry to reduce the moisture content of the wood to 12%. Put the wood into the heat treatment box, turn on the water vapor switch, rapidly raise it to 140 °C at a speed of 15 °C / h, keep it warm for 45 minutes, and dry the wood at high temperature to reduce the moisture content inside the wood to 0; raise the temperature to 180°C, keep the heat treatment for 4 hours; turn off the water vapor switch, reduce the temperature of the heat treatment box, when the temperature of the heat treatment box drops below 80°C, turn on the water vapor switch, adjust the moisture content of the wood to 8%, and remove the wood.

Embodiment 3

[0026] Soak poplar wood with a thickness of 40mm, a width of 100mm, and a length of 1000mm in 40% aqueous glycerin solution at room temperature and pressure for 48 hours, take out the test material, and air-dry to reduce the moisture content of the wood to 15%. Put the wood into the heat treatment box, turn on the water vapor switch, rapidly raise it to 140 °C at a speed of 20 °C / h, keep it warm for 45 minutes, and dry the wood at high temperature to reduce the moisture content inside the wood to 0; raise the temperature to 200°C, keep heat treatment for 4 hours; turn off the water vapor switch, reduce the temperature of the heat treatment box, when the temperature of the heat treatment box drops below 80°C, turn on the water vapor switch, adjust the moisture content of the wood to 10%, and remove the wood.

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Abstract

The invention discloses a pretreatment method for improving dimension stability of timber. The method comprises the following steps: pretreating timber with glycerin and then carrying out air seasoning on the timber so as to enable the water content of the timber to decline to less than 15%; putting the timber into a heat treatment box, turning on a vapor switch, allowing the temperature of the heat treatment box to rapidly rise to 140 DEG C at a rate of 10 to 20 DEG C/h, keeping the temperature for 30 to 60 min, and drying the timber at a high temperature so as to enable the water content of the timber to decline to 0; allowing the temperature to rise to 160 DEG C to 200 DEG C and maintaining heat treatment for 2 to 5 h; turning off the vapor switch, allowing the temperature of the heat treatment box to decline, turning on the vapor switch when the temperature of the heat treatment box declines to 80 DEG C, adjusting the water content of the timber to be 7% to 10%, and moving the timber out. According to the invention, pretreatment of the timber with an aqueous solution of glycerin enables pyrolysis of chemical components in the timber to be accelerated, molecular chains of the timber to break and to form new crosslinked bond, and dimension stability and corrosion resistance of the timber to be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of wood processing and relates to wood modification treatment technology, in particular to a pretreatment method for improving the dimensional stability of wood. Background technique [0002] my country is a major consumer of timber and wood products in the world, but it is also one of the countries with the least per capita forest (timber) resources. Large-diameter natural forest resources are increasingly in short supply. In recent years, the Chinese government has vigorously promoted the construction of fast-growing plantations to alleviate the contradiction between timber supply and demand. However, because these materials contain a large amount of hydroxyl groups, they will shrink and swell with the temperature and humidity of the surrounding environment during use, resulting in deformation and cracking of wood products. In addition, this type of wood is susceptible to fungal and insect attack, result...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B27K3/08B27K3/52
Inventor 闫丽党娅萍雷亚芳
Owner NORTHWEST A & F UNIV
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