• 2023-09-04
• 538
• 5 Comments

Injection mold exhaust bad solution

The exhaust gas of injection mold is a problem that can not be ignored in mold design. Poor exhaust will cause many problems. For example: pores, voids, burning, bubbles, surface silver lines, obvious welding lines and so on.

The gas accumulated in the mold of the injection mold factory mainly has the following sources:

1. Air stored in the feed system and cavity.

2. Water vapor generated by the evaporation of water contained in plastics at high temperatures.

3. Gas produced by plastic decomposition.

4. Gases generated by volatilization or chemical reflection of certain additives in plastics

5. Air and water in the feed!

The basic design points can be summarized as follows:

1. Exhaust to ensure rapid, complete, exhaust speed and mold filling speed to adapt;

2. Exhaust groove as far as possible in the plastic parts thicker forming parts;

3. The exhaust groove should be opened on the parting surface as far as possible;

4. The exhaust tank should be located at the end and junction of the material flow as far as possible, such as the end of the cold material well;

5. In order to facilitate mold manufacturing and mold cleaning, the exhaust groove should be located on one side of the concave mold as far as possible;

6. The direction of the exhaust groove should not face the operating surface to prevent the leakage of material during injection molding;

7. The exhaust groove should not have a * Angle to prevent the accumulation of cold materials;

8. The size and size of the exhaust groove must be appropriate (the general thickness is about 0.2-0.3mm), and the selection and processing are made according to the specific materials and product requirements, and the flash is avoided as far as possible.

Common exhaust forms are:

1. Exhaust air through the exhaust tank or hole

2. Parting surface exhaust

3. Insert slot exhaust

4. Exhaust the push rod or thimble gap

5. Powder burning combined with gold nugget exhaust

6. Set the exhaust rod to force exhaust

7. The application of vacuum exhaust machine to achieve the effect of active exhaust and complete exhaust.

8. Mold exhaust steel, exhaust bolt and other exhaust