1. The exhaust in the injection mold is not smooth, and there is often gas in the injection mold. What is the reason for this?
The main reason for the failure is the air in the pouring system and mold cavity. Some raw materials contain moisture that has not been dried out. They will be vaporized into steam at high temperature. Because the temperature is too high during injection molding, some unstable plastics will decompose and produce gas; Some additives in plastic raw materials volatilize or produce gas through mutual chemical reaction. At the same time, the cause of poor exhaust also needs to be found out as soon as possible.
2. Stamping burr
If the die clearance is too large or uneven, readjust the die clearance. 2. If the die material and heat treatment are improper, resulting in the inverted cone of the die or the cutting edge is not sharp, the material selection should be reasonable. The working part of the die should be made of cemented carbide, and the heat treatment method should be reasonable. 3. Punching wear, grinding punch or insert. 4. If the punch is too deep into the die, adjust the depth of the punch into the die. 5. If the guiding structure is not precise or the operation is improper, check and repair the guiding accuracy of the guide post and guide sleeve in the mold and the punch, and standardize the operation of the punch.
3. Difficulty in sprue stripping
In the process of injection molding, the gate is stuck in the gate sleeve and is not easy to come out. When the mold is opened, the product is cracked and damaged. In addition, the operator must knock the tip of the copper bar out of the nozzle to loosen it before demoulding, which seriously affects the production efficiency.
The taper hole of the gate has poor finish, and there are knife marks on the circumference of the inner hole. Secondly, the material is too soft, the small end of the taper hole is deformed or damaged after using for a period of time, and the spherical radian of the nozzle is too small, resulting in the rivet head of the gate material here. The taper hole of the sprue sleeve is difficult to machine, so standard parts should be used as far as possible. If it is necessary to machine by yourself, you should also make or buy a special reamer. The taper hole needs to be ground to above Ra0.4. In addition, the gate pull rod or gate ejection must be set.