Plastic mold assembly skills

- Nov 22, 2017-

Plastic mold type more, even the same kind of mold, due to different types of plastic forming, the beginning and the accuracy requirements of different assembly methods are not the same. So before the assembly should be carefully studied. The parts drawing assembly drawings, understand all parts of the function, characteristics and technical requirements, determine the assembly reference. Through the assembly. Finally, fully meet the quality indexes of the product, the technical requirements of precision mold movement and use of the process.

1. assembly datum assembly standard can be roughly divided into:

(1) the main working parts in the plastic mold such as core, cavity and insert as the benchmark assembly, other parts of the mold have assembly datum parts for preparation and assembly.

(2) the base surface of the guide plate of the guide post or die is used as the assembly datum to repair and assemble

2. assembly precision of die

(1) the accuracy of each component, such as distance, size accuracy, coaxiality, equality, perpendicularity, etc.

(2) relative motion accuracy, such as transmission accuracy, linear motion and rotation accuracy

(3) coordination precision and contact precision, such as fit clearance, interference fit, contact condition, etc.

(4) the wall thickness of the plastic forming parts. When the new mold is made, the wall thickness of the forming parts should be limited to the lower limit of the size

3. repair Principle

(1) repair draft, in principle, should ensure that the main cavity size in the size tolerance range, the core should ensure that the small size in the end parts dimension tolerance range.

(2) at the corner radius, the cavity should be smaller, the core should be larger.

(3) when the mould has both horizontal parting surface and vertical parting surface, the horizontal parting surface should be left a little gap when the vertical parting surface is contacted. The small mold can only be painted with red and contact with each other, and the clearance of the large mould is about 0.02mm

(4) for the die with bevel die, the gap of 0.02-0.03mm should be left at the parting surface after the slope is closed

(5) the connection between the arc and the straight line on the surface should be smooth, the surface is not allowed to have dents, and the cutting lines should be consistent with the direction of the die opening