Progress in Research on Fire Retardant–Treated Wood and Wood-Based Composites: A Chinese Perspective

Abstract

Research on fire retardant-treated wood and wood-based composites has been conducted in China for over two decades. Although many kinds of fire retardants for wood and wood-based composites have been studied, the focus is still mainly on compounds or mixtures containing phosphorus, nitrogen, and boron, which can be used in a water solution for solid wood impregnation. Fire-retardant treatment methods for wood-based panels are either pretreatment of veneers, fibers, particles, or strands before hot pressing or impregnation of waterproof panels with fire-retardant solutions. Though attempts have been made in laboratories and factories to mix the fire retardants with glues, it has proven very difficult to spray the glue smoothly and to deliver effective amounts of fire retardants during the manufacture of panels. The mechanisms of phosphorusnitrogen-boron fire retardants have been investigated systematically. The results indicate that the phosphorus-nitrogen compounds and the boron compounds are highly synergistic in effective fire-retardant formulations. The catalytic charring effect of a fire retardant on wood is a key factor in its efficacy. A chemical fire-retardant mechanism for boric acid is also proposed. Research on fire retardants for wood-plastic composites has been attracting more attention in recent years; however, most results are preliminary because of the difficulty in identifying or formulating a fire-retardant system that is effective for both wood and plastics. Only preliminary research has been conducted on smoke suppression for wood; innovative efforts will be needed to conduct further research.

Recent research and development advances of wood science and technology in China: impacts of funding support from National Natural Science Foundation of China

“…Research contents included interfacial science, rheology and extrusion simulation, fiber reinforcement, creep and fracture, aging mechanism and weatherability, flame retardancy and smoke suppression mechanism, and bonding method (Guo and Wang 2008;Guo et al 2012;Du et al 2010;Wang et al 2010). Many kinds of WPC products including industrial tray/pallets, floors, windows, and doors have been fabricated and successively put into commercial use.…”

A Novel Method for Calcium Carbonate Deposition in Wood That Increases Carbon Dioxide Concentration and Fire Resistance

“…Fire retardancy in wood products is regularly achieved by superficial or integral impregnation with chemical formulations. In this sense, a wide range of very effective formulations, mostly based on the action of phosphorus, nitrogen, and boron compounds, have been developed [5]. However, nowadays many of these formulations have been questioned because of their possible toxic effects on living organisms [6][7][8].…”

Processing of Pinus sylvestris into remarkable heat- insulating, thermally stable, and flame-retarded materials by combining the flame retardant impregnation and densification treatment

“…When heated, ame retardants retard wood combustion and pyrolysis to achieve well ame retardancy (Wang et al 2010;Renner et al 2021). Li et al (2021) uniformly impregnated wood with water-soluble ame retardant (consisting of phytic acid, hydrolyzed collagen, and glycerol) by full cell vacuum-pressure impregnation.…”