Injection molding plastic parts appear flash solution

Injection molding plastic parts appear flash solution

A. The reasons of the burrs

1-1 mold parting surface (PL) sliding surface not to cooperate. 1-2 injection pressure is too high for 1-3 injection machine offset 1-4 lock to touch

2. The associated knowledge

2-1 mold parting surface of PL, the matching of the sliding surface, the ejection pin, block and so on. Constitute the mould of the gap between various slot, if material flow has become a flash. Flash a wedge block. Have gradually become big trend.

2-2 remove burrs of plastic parts on repair mold for the principle, on account of the bad forming conditions set at that time the emergence of flash, lower the temperature in the cylinder should be adopted. Lower mold temperature, injection speed reduce material liquidity in the direction of the setting parameters. But, in this would cause products should be paid attention to the internal stresses in the residual.

3. The solution

3-1 instant: reduce the injection pressure, decrease the temperature of the heating cylinder. Reduce the injection speed. 3-2 short term: grinding burrs in the mold surface. 3-3 long: mould using rigid steel material.

4. Because of the difference of the material

4-1 for liquid material is prone to flash, so the mold parting surface would have to close.

4-2 crystalline materials during melt viscosity is very low. Especially need to mould parting surface closely.

5. Reference

5-1 should be paid attention to, for the mould and excessive clamping pressure also can produce flash, parting surface, between the clip into the foreign body damage both mold, and produces the burrs.

5-2 mold material often use S50C JJS (Japan standard domestic 50 # steel) using HRC30 hardening of the special steel in advance, it is difficult to produce burrs in parting surface

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