What is a polyurethane screen, how to make a polyurethane screen? The following small series introduces us to the pouring method of polyurethane screen panels:
1. Mechanical pouring of polyurethane screen panels
In the pouring machine, the A tank is a prepolymer, the B tank is a chain extender, and the heating system is initiated to make the A and B materials reach the requested temperature, and then the metering pump speed and displacement are scheduled to reach the planned mixing ratio. When the pouring switch is started, the A and B materials can be poured after high-speed and uniform mixing in the mixing chamber. When the pouring is completed, the A and B tanks are automatically turned into a self-circulating state. The mechanical casting has the advantages of accurate ratio, stable metering, uniform mixing, no bubble generation, stable temperature, and precise and reliable features. The preheating of the prepolymer, the defoaming, the melting of the chain extender, and the metering, mixing and pouring of the prepolymer and the chain extender are all terminated by the computer in the casting machine, which can achieve continuous production and high production power. The quality of the products is stable and suitable for the production of large quantities and large and medium-sized products.
2, manual pouring of polyurethane screen panels
The weighed prepolymer and the chain extender are uniformly mixed under certain conditions, and can be written into the mold, and can be demolded by heating for 1 hour. Hand-casting has the characteristics of low capital, low cost, and simple sensitivity. It is suitable for the production of small and medium-sized products. However, due to the short pouring time, it is easy to carry bubbles, the mixing is not easy to be uniform, the production power is low, the labor intensity is high, and the quality of the goods is not It is stable, so polyurethane elastomer casting machines are usually used in the production of polyurethane screen panels.
3. Vulcanization and curing of polyurethane screen
The vulcanization process of the product in the mold is called forming vulcanization, and the temperature selection can be as high as possible without damaging its chemical structure, so as to accelerate the chain extension crosslinking reaction, shorten the demolding time, and improve the utilization rate of the mold and equipment.
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