For a long time, halogen flame retardants for the advantages of small dosage, the effect is obvious, moderate price and widely research and application, when burnt. but it produces toxic smoke and corrosive gas, cause harm to the environment and personal, thus gradually by other halogen-free flame retardants (nitrogen, phosphorus, silicon, inflating and aluminium-magnesium type flame retardant). At present, domestic and foreign patents and technologies are difficult to meet the needs of medium and high-end deep embossed deck wood plastic furniture materials for beauty, strength, flame retardant and cost. Therefore, the development of a low cost and high strength flame retardant plastic wood composite material is particularly important, has a good market prospect and social benefits, improve the application of plastic wood composite material added value.

Application of Halogen-free Flame Retardant In Plastic Wood Composite Material
Silicon-based Flame Retardant

The flame retardant mechanism of silicon flame retardant is that during the combustion of organic silicon compounds, molecular Si-C bond is transformed into Si-O bond, forming a composite layer of white residue and carbide, preventing volatiles from escaping, preventing oxygen from contacting with the substrate, and preventing melt from dropping, thus playing a flame retardant role. Inorganic SiO2 itself can act as the covering layer of the material. Moreover, it can also play a reinforcing role in the mechanical properties of plastic wood composite materials.

Nitrogen-phosphorus Flame Retardant

The mechanism of deep embossed deck plastic wood composite material lies in the thermal decomposition of phosphorus and nitrogen compounds need to absorb a lot of heat, the phosphoric acid generated can promote the dehydration of polymer carbonization to form a graphite-like coke layer, heat insulation and oxygen isolation, delaying the effect of material combustion. APP(Ammonium Polyphosphate) and Inorganic Red Phosphorus (INP) are the focus of flame retardant research of plastic wood composite materials.

Expansive Flame Retardant

With nitrogen, phosphorus and carbon as the main elements, the system itself has a synergistic effect. The flame retardant mechanism lies in the formation of a carbon foam layer when the material burns, which plays the roles of oxygen isolation, heat insulation, drip prevention and smoke suppression.

Aluminium-magnesium Flame Retardant

This kind of flame retardant for environmental obvious advantages, low price, is increasingly becoming the concerned focus of scholars at home and abroad, the mechanism of flame retardant is compound can absorb a lot of energy, decomposition of water vapour dilution in the surrounding air O2, compound residue cover in the surface of the substrate material, further blocking material internal contact with air.

Application of Halogen-free Flame Retardant In Deep Embossed Deck
The Problem of Flame Retardant

The research on flame retardant of deep embossed deck plastic wood composite is still in its infancy, and there are still many problems to be solved in the process of processing.

1) most flame retardants are additive powder materials, polarity is generally strong, with a hydrophilic group, and lipophilic polymer matrix is not compatible, adding a small amount, can not reach the flame retardant effect; When the amount is large, it is easy to produce the gap with the matrix interface, which reduces the physical and mechanical properties of the plastic wood composite.

2) The flame retardant of plastic wood composite not only involves the flame retardant of wood and polymer materials but also has something to do with the interaction between the two. The flame retardant situation is very complex, so some flame retardants suitable for wood or plastic applications can not be directly applied to the flame retardant of plastic wood composite materials.

3) The efficiency of a single flame retardant is low, which has a great impact on the physical and mechanical properties of polymer materials. The co-effect of multiple flame retardants is a hot spot. However, interaction or other new problems may occur in the mixing process of various flame retardants, so it is very important to explore the synergistic mechanism and the modification of flame retardants in the deep embossed deck.

Development Prospect of Deep Embossed Deck Plastic Wood Materials

The main development directions of the research on the flame retardant properties of wood-plastic composites can be summarized as follows:

1) Continue to study new coupling agents to improve the binding rate of flame retardant and WPC composites.

2) To study a multi-effect flame retardant for wood-plastic composites, which not only improves the flame retardant performance of wood-plastic composites but also gives them anti-corrosion, weather resistance, insect resistance, aging resistance and other functions.

3) A breakthrough should be made in the way of adding flame retardants so that the addition of flame retardants can be realized under the condition of the existing wood-plastic composite material production equipment (or slightly improved).

4) Develop a new flame retardant to achieve the flame retardant effect without reducing the mechanical properties of deep embossed deck composites.