1. When cooled with water after ejection, increase the temperature of the cooling water or reduce the water-cooling time

6. Is there any soot or dust mixed in from the vents of the hopper loader, or whether there are foreign substances generated by the hopper loader itself?

3. Are there any other resins mixed in the pre-dryer, or are there any foreign substances caused by friction between the dryer and the receiver?

This is caused because the resin does not fill the cavity fully. To prevent its occurrence, we can take the following measures:

The defects in the injection molding of acrylic PMMA usually include: short shot, silver streaks, sink marks, voids, jetting, weld marks, gray / black specks, cracking, warpage, and material impurity, while the preventive measures against them are usually:

7. Increase the cross-sectional area of the gate (main runner, branch runner, and feed port) and reduce its length, to allow the resin to flow more easily and reduce the barrel temperature.

These are the cracks that occur on the surface or the contact surface with the insert of a product. When viewed from a certain angle, it will flicker and emit light. The causes of this defect are relatively complicated, which, however, can be prevented by taking the following measures:

5. Does the strong friction between the metal wall of the hopper loader and the acrylic pellets cause the metal wall to peel off?

PMMA acrylic are widely used in all aspects of the optical field, so it is extremely necessary to prevent the mixing of impurities. Usually, there are many ways for foreign substances to be mixed in. It is time-consuming to find out the reason, but you can start with the following aspects:

These are the voids that occur where the product wall is thick. For transparent PMMA products, they will become an exterior defect that cannot be remedied later. Insufficient drying before molding or excessive barrel temperature may cause voids to occur in areas other than the center of the thick wall. If the shrinkage is concentrated in the thick wall, voids will appear in the center of the thick wall. It can be solved by the prevention of shrinkage, or by the following measures:

These are the silver-white streaks on the product surface which are generated in the feed port along the flow direction of the resin. Caused by multifaceted factors, silver streaks can be prevented by taking the following measures:

5. Increase the cross-sectional area of the gate (main runner, branch runner, and feed port), and reduce its length, to allow the resin to flow more easily

9. Increase the cross-sectional area of the gate (main runner, branch runner, and feed port) and reduce its length, to allow the resin to flow more easily.

These are the ring-shaped stripes that occur on the surface of a product and are centered around the feed port. It can be prevented by taking the following measures: