④ Water-soluble fire-retardant coatings have poor waterproof and moisture-proof properties, and solvent-based fire-retardant coatings pollute the environment. There is no decorative fire-retardant coating with a service life of more than 3 years.
New technology for fire retardant impregnation treatment of wood and its products
Generally, flame retardants are required to be evenly distributed inside the wood material. In order to improve the permeability and depth of penetration, researchers at home and abroad have proposed the following new impregnation methods.
(1) CO2 supercritical fluid treatment of wood technology: this method can treat almost all kinds of wood without obvious adverse effects on the treated wood.
(2) Wood laser scoring method: The laser scoring method does not damage the wood structure and makes it easy to inject the medicine . Compared with the claw-shaped knife scoring method, the laser scoring method has a 50% increase in the liquid medicine impregnated into the wood.
(3) Low-pressure steam blasting method: The low-pressure steam blasting method can destroy the locked pits, improve the intercellular conductivity and improve the permeability. The electron micrographs show that the pits are part of the blasting treatment. Selective destruction.
(4) Compression pre-treatment technology: first compress the wood horizontally to selectively destroy the periphery of the pits and the pit membrane. The intrusion body in the perforated pipe is also destroyed, which improves the permeability.
(5) Hot water (steam) treatment method: For coniferous woods, hot water (steam) treatment can remove the arabinogalactose gum covering the pores and open the blocked pores, thereby improving the penetration The greater the strength of the cooking treatment, the greater the effect of improving permeability. The electron micrographs show that there are cracked pit plugs after the cooking treatment . Using microwave heating to pretreat the wood can not only increase the heating speed, but also improve the permeability of the medicine.
(6) Oscillation and pressure treatment method: The method of applying oscillation while applying pressure to the wood. After the shock treatment, the penetration and absorption of the drug increased significantly.
(7) For the use of enzymes, microorganisms, and bacteria to improve the permeability of wood.
(8) Acoustic wave and ultrasonic treatment method: While the wood is pressurized, the effect of sound wave or ultrasonic wave is also a research direction to improve the permeability of wood.
(9) Centrifugal rotation treatment technology: the wood is impregnated in a centrifugal separator, and the centrifugal impregnation under normal pressure increases the absorption of chemicals by the wood.
Flame retardant and treatment process for new wood materials
Wood flame retardants are mainly inorganic P-N series. In order to improve the flame retardant effect and resistance to loss, reduce the moisture absorption rate and toxicity, the following studies have been mainly carried out:
(1) Choose appropriate additives and emulsifiers, and formulate water-insoluble flame retardants into aqueous solutions or emulsions for flame retardant treatment of wood materials to reduce the moisture absorption, loss rate, and resistance of flame retardant wood materials. The influence of fuel on the strength of wood materials.
(2) The double diffusion method is used to generate water-insoluble compounds in the wood material.
(3) Resin-based flame retardants not only impart flame retardant effects to wood materials, but also improve the physical and mechanical properties of wood materials.
(4) Research on fire-retardant, anti-corrosion, and insect-proof multifunctional wood material treatment agent.
(5) Research on synergists and anti-smoke agents.