The flame retardance of wood-plastic composites is usually tested by the limiting oxygen index tester, which is an experimental equipment independently developed and produced by Standard Group (Hong Kong) Co., Ltd.
As a new type of material, wood-plastic composite material fully embodies the advantages of wood and plastic, and does not contain formaldehyde. It is widely used in outdoor building materials abroad. Because thermoplastic and wood fiber are both hydrocarbons, which are easy to burn in case of open fire or heating, WPC is a kind of flammable composite material, and a large number of harmful gases will be generated during the combustion process, which limits its scope of use, so it is often necessary to add flame retardant in the production process. The flame retardancy of wood-plastic composites involves the flame retardancy of wood components and polymers. Inorganic flame retardants (hydrogen oxidation, hydrogen oxidation, etc.), halogen-containing flame retardants (decabromodiphenyl ether, etc.) and phosphorus-containing flame retardants (ammonium polyphosphate, phosphate ester, etc.) are often used for the flame retardance of polyolefins and wood. Among them, inorganic flame retardants such as hydrogen oxidation and hydrogen oxidation have attracted attention due to their low price, excellent thermal stability, non-toxicity and smoke suppression.
Test material:
The wood shavings are mainly Yunnan pine and eucalyptus, with an initial moisture content of 5.8%. High density polyethylene (HDPE) granular material, with a density of 0.941g/cm3~0.963g/cm3. Industrial grade silane coupling agent. The decomposition temperature is 350 ℃. Nano hydrogen oxide (nano ATH), the short axis direction is 50-60 nm, and the long axis direction is 300-400 nm. Analyze pure non-nanometer hydrogen oxide (non-nanometer ATH).
Preparation of wood-plastic composite:
The wood-plastic ratio of wood-plastic composite is 6:4, and the dosage of silane coupling agent is 2%. Fully mix plastic, particle, coupling agent and flame retardant in the mixer according to the ratio, and manually pave them into 305mmx350mm loose slab. Pre-press at room temperature (the pre-pressure is 1MPa, and the time of pre-pressing is 30s), and then place it in the eight-plate vulcanizer for hot-pressing molding. The nominal density of plastic composite is set as 0.89/cm3, and the nominal thickness is 10xma. Main hot pressing parameters; The hot-pressing temperature is 180 ℃. The hot-pressing time is 12 minutes, and the hot-pressing pressure is 2 MPa.