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Author: MULAN –Plastic Molding Manufacturer
The transparent panel injection mold adopts PMMA plastic injection molding. PMMA has the characteristics of high light transmittance, but poor fluidity and difficult injection molding process. Therefore, it is necessary to pay more attention to the design of the transparent panel injection mold and the injection molding process. This article mainly introduces the design points of injection mold for transparent panel.
1. Determine the number of mold cavities according to the size and thickness of the product, and the amount of glue injected by the injection molding machine. The transparent panel is a balanced flow channel. Generally, one mold has two cavities. When the size is small, four cavities can be opened. If more than four cavities are opened, the operation difficulty of the injection molding machine will be increased, resulting in an increase in the defective rate. 2. The selection of the parting surface, because the shape of the transparent panel is simple, the parting surface is generally selected along the edge of the plastic part to leave the movable mold of the plastic part.
In addition, attention should be paid to checking the demoulding angle of the edge of the plastic part. The demoulding angle should be large enough, and whether there is a small R on the parting surface, etc. 3. The selection of the injection position of the transparent panel injection mold is very important. For the PMMA mold, the mold flow channel should be bent into an S shape, and the end of the flow channel is designed with a long cold material well, otherwise it is easy to produce air marks and melt glue during production. trace. The large end of the injection molded part is selected as a gate, so that the plastic can easily fill the cavity, and the glue line between the two holes is not obvious.
4. For the design of the exhaust position, generally transparent panels are not allowed to have thimble marks, so it is necessary to open an auxiliary flow channel to help the ejection, and this flow channel also plays the role of exhaust. 5. The selection of steel used for the injection mold of the transparent panel, the general output is below 100,000, and Japanese NAK80 can be used. If the output is large, it is necessary to use S136 or other steel with good grinding properties, heat treatment to HRC48-52, after finishing Polished, can get very good results. 6. Transparent panel mold ejection design, generally transparent boards are not allowed to have thimble traces, the ejection of plastic parts is the ejector pin designed at the injection port, on the small boss of the plastic part, lengthen the glue position, add an ejector pin, two A thimble is ejected, and the plastic demoulding is smooth.
7. Cooling system design, the cooling system is designed for the front and rear molds of the transparent panel injection mold to ensure that the process parameters can be adjusted well during the injection molding process. 8. The main channel of the injection mold for the transparent panel is facing the cold material well, and the Z-shaped pull rod design must be used, and the reverse pull material cannot be used.