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Taizhou Union Plastic Mould Co.,Ltd

ADD:No.26, MaoFeng Street, Beicheng Development Area, Huangyan Dist., Taizhou, Zhejiang, China

Post Code: 312080

Contact:Ms vicky






Precision Injection Mold Processing Fusion Mark Solution
Jul 03, 2018

In the case of precision injection mold processing, if the melt fills the cavity, if two or more melts are cooled at the front edge when they meet, so that they cannot be completely fused, a linear groove is formed at the junction to form a weld mark. .

Generally, the precision injection mold processing is easy to cause the problem of weld lines, which causes the problem of precision injection mold processing. We summarize the following points:

First, the reason: the mold is poorly exhausted. First, check if the vent hole of the mold is blocked by the solidified material or other objects of the melt, and there is no foreign matter at the gate.

Solution: If the carbonization point still occurs after the obstruction is removed, the vent hole should be added at the mold receiving point, or the rendezvous flow can be accelerated by repositioning the gate, or appropriately reducing the clamping force and increasing the exhaust gap. In terms of process operation, auxiliary measures such as lowering the temperature of the material and the temperature of the mold, shortening the injection time of the high pressure, and reducing the injection pressure can also be adopted.

Second, the reason: the use of precision injection mold processing release agent is not appropriate.

Solution: In the processing of precision injection molds, it is generally only necessary to apply a small amount of release agent evenly in the parts that are not easy to demold, such as threads. In principle, the amount of release agent should be minimized.

Third, the reason: the temperature of the precision injection mold processing material is too low, the splitting and converging performance of the low temperature melt material is poor, and it is easy to form a weld line. If the inner and outer surfaces of the plastic part are welded at the same place, the welding is often caused by poor welding temperature.

Solution: The temperature of the barrel and nozzle can be appropriately increased, or the injection cycle can be extended to increase the temperature of the material. At the same time, the throughput of the coolant in the mold should be controlled to appropriately increase the temperature of the three-color vertical injection mold. Under normal circumstances, the strength of the welded joints of the plastic parts is poor. If the corresponding parts of the welded joints in the automobile injection mold are locally heated to increase the local temperature of the welded parts of the molded parts, the strength of the welded parts of the plastic parts can be improved.

Fourth, the reason: precision injection mold processing is not reasonable in design.

Solution: If the wall thickness of the plastic part is too thin or the thickness is too wide and the insert is too much, it will cause poor welding. When designing the plastic part structure, it should be ensured that the thinnest part of the plastic part must be larger than the minimum wall thickness allowed during molding. In addition, the use of the insert should be minimized and the wall thickness should be as uniform as possible.