Sound barriers are mainly used for sound insulation and noise reduction on roads, expressways, elevated composite roads and other noise sources.At present, there are many types of sound-absorbing and insulating panels used for sound barriers. According to the materials, they can be mainly divided into metal-based sound-absorbing panels and non-metal material sound-absorbing panels.Railway sound barriers are used in harsh environmental conditions. Although metal sound barriers can meet sound absorption, sound insulation and mechanical requirements, their durability is poor, and their general service life is about ten years.The use of non-metallic materials can save costs on the one hand and greatly extend the service life of the sound barrier on the other. Non-metallic materials have the following characteristics: (1) high surface hardness, their flexural strength and flexural modulus reach more than 50MPa and 4.5GPa respectively, and strong load-bearing capacity; (2) good dimensional stability, no cracking, no warping; ( 3) Good durability: water-resistant, fire-resistant, corrosion-resistant, UV-resistant, especially suitable for areas with high temperature and humidity, with a service life of up to 2550 years; (4) It can be reused and recycled, environmentally friendly, etc. However, non-metal material sound-absorbing panels also have problems such as mediocre sound insulation effect and heavy weight, which makes them difficult to construct and maintain and limits their application fields. New fiber-reinforced wood-plastic composite foam sound-absorbing panels to overcome the shortcomings of existing technology.
There is an invention patent (CN 110053321 A) that provides a fiber-reinforced wood-plastic composite foam sound-absorbing panel, which includes two skin layers and a foam layer located between the two skin layers;The skin layer is made of the following raw materials by weight: wood powder 4050, polyethylene resin particles 2030, skin layer coupling agent 23, anti-aging additive 23, flame retardant 23, lubricant 12 and light calcium carbonate 23;The foaming layer is made of the following raw materials by weight: chopped waste wood-plastic composite fiber 78, foaming layer coupling agent 12, foaming agent 45, foaming regulator 12 and polyurethane 79. Among them, the coupling agent for the skin layer and the coupling agent for the foaming layer both refer to coupling agents, specifically referring to the coupling agent used to make the skin layer and the coupling agent used to make the foaming layer respectively. Chopped waste wood-plastic composite fiber refers to the shorter-length products obtained by secondary crushing of waste wood-plastic composite boards.
Furthermore, the present invention provides a fiber-reinforced wood-plastic composite foam sound-absorbing panel, which may also have the following characteristics:Among them, the preparation method of the skin layer is: Step 1: Mix wood powder, polyethylene resin particles, skin layer coupling agent, anti-aging additive, flame retardant, lubricant and light calcium carbonate at 8090°C,Then it is cooled to form a protective layer on the surface of the wood powder to prevent it from carbonizing. Cooling can solidify the protective layer;Step 2: Heat the mixture obtained in Step 1 to 130-160°C to melt; Step 3: Extrude the melt obtained in Step 2 into a mold, cool it and form it to obtain a skin layer.The skin layer refers to the skin layer formed and shaped in the mold, including two skin layers, with a hollow space between the two skin layers, formed by the inner mold in the mold.After the inner mold is extracted, the hollow part between the two skin layers is used to continue making the foam layer.Furthermore, the present invention provides a fiber-reinforced wood-plastic composite foam sound-absorbing board, which may also have the following characteristics: in step three, before extruding the melt into the mold, the mold is pre-cooled with 38°C water.
Furthermore, the invention provides a fiber-reinforced wood-plastic composite foam sound-absorbing panel, which can also have the following characteristics:Among them, the preparation method of the foaming layer is: Step A, mix the chopped waste wood-plastic composite fiber and the coupling agent of the foaming layer, then add it to the foaming agent, foaming regulator and polyurethane, stir quickly and mix evenly ;Step B: Inject the mixture obtained in step A into a mold with a shaped skin layer, and raise the mold temperature to 40±5°C for foaming;Step C: After the foaming is completed, raise the mold temperature to 60±5°C and perform aging. The aging time is 6 minutes. After aging, cool to obtain a foamed layer integrated with the skin layer.
The new fiber-reinforced wood-plastic composite foam sound-absorbing board includes two skin layers and a foam layer between the skin layers. A foaming agent is added to the foam layer to form some honeycomb pores.The wood-plastic composite foam sound-absorbing board made in this way is not only light in weight but high in hardness, but also has a microporous structure with good sound absorption and sound insulation effects. Among them, the raw materials of the foaming layer also include chopped waste wood-plastic composite fibers made by two crushing processes, which can increase the overall strength and act as a "reinforcement". It has the advantages of light weight, high hardness and excellent sound insulation effect.