Usually, we will inevitably encounter various problems in the production of injection molding products. The following is the World State small series for you to sort out four problem solutions for reference.
First, the solution to the bubble phenomenon in the molding process of injection molding products
According to the causes of bubbles, the solutions are as follows:
1. When the wall thickness of the product is large, the cooling rate of the outer surface is faster than that of the center. Therefore, as the cooling proceeds, the plastic resin in the center shrinked while expanding to the surface, causing insufficient filling in the center. This situation is called vacuum bubble solution mainly includes:
a. According to the wall thickness, determine the reasonable gate, gate size. General gate height should be 50% ~ 60% of the product wall thickness.
b. Until the gate is closed, sufficient supplementary injection material is left.
c. The injection time should be slightly longer than the gate sealing time.
d. Reduce the injection speed and increase the injection pressure.
e. Materials with high melt viscosity grades are used.
2. For bubbles caused by the production of volatile gases, the main solutions are:
a. Fully pre-drying.
b. Reduce the temperature of the resin to avoid the generation of decomposition gases.
3. The bubbles caused by poor fluidity can be solved by increasing the temperature of the resin and the mold and increasing the injection speed.
Injection molding mold
Second, the cause analysis of the main channel sticky mold during injection molding
Causes and elimination methods of main channel sticky mold during injection molding:
1. The cooling time is too short, the main channel has not solidified.
2. The slope of the main track is not enough, and the slope of its release should be increased.
3. Improper matching size of main channel bushing and nozzle causes leakage.
4. The main channel is rough and there is no cooling well in the main channel.
5. If the temperature of the nozzle is too low, the temperature should be raised.
Injection molding equipment
Third, the cause analysis of the slow production of injection molding products
The causes and solutions of slow production during injection molding are as follows:
1. High plastic temperature and mold temperature result in long cooling time.
2. For a long time of melting, the back pressure should be reduced, less raw material should be used to prevent overhead, and the cooling of the feeding section should be sufficient.
3. The operation of the machine is slow, and it can be adjusted from the oil circuit and circuit to speed up appropriately.
4. The design of the mold should be convenient for demoulding and try to design it into automatic operation.
5. The thickness of the wall is too large, resulting in too long cooling time.
6. The nozzle drooling, hindering the normal production. A self-locking nozzle should be used or the temperature of the nozzle should be reduced.
7. The heat supply of the barrel is insufficient, and the machine with large plasticizing capacity should be used or the preheating of the material should be strengthened.
Injection molding
Fourth, cause analysis of injection molding products molding dissatisfaction
The main reasons for the dissatisfaction of injection molding products are lack of material and improper injection pressure and speed (including resistance caused by pressure over consumption).
It may be caused by the following aspects:
1. Reasons for injection molding machine:
The plasticizing amount or heating rate of the machine is uncertain, and the machine with large plasticizing amount and heating power should be selected;
The wear of the screw and the barrel or the rubber head causes the material to be returned and the actual filling modulus is not in the middle; The actual temperature of the barrel is too low due to the failure of the heating system such as thermocouple or heating ring; The wear of the sealing element of the injection cylinder causes oil leakage or backflow, and can not reach the required injection pressure; Too small hole in the nozzle or improper adjustment of the center of the nozzle will cause too much resistance and cause pressure consumption.
2. Reasons for injection mold:
a. The local or overall temperature of the mold is too low to cause difficulties in feeding, and the mold temperature should be appropriately increased;
b. The distribution of the mold cavity is unbalanced, and the thickness of the workpiece wall is too thin to cause excessive pressure consumption and poor mold filling. The wall thickness of the whole piece or part should be increased or the auxiliary flow or sprue can be set up near the filling deficiency.
c. The flow channel of the mold is too small to cause pressure loss; When it is too large, it will appear weak shooting glue; Too rough will cause parts are not full. The size of the flow channel should be set appropriately, and the transition between the main channel and the shunt channel, the gate or the turn itself should be applied appropriately
The arc transition.
d. Poor exhaust of the mold. The material entering the cavity is blocked by the gas pressure that can not be discharged in time, resulting in filling dissatisfaction. Can make full use of the gap of the screw exhaust or reduce the clamping force to use the type surface exhaust, when necessary to open the exhaust channel or pores.
ZIBO HUIWEN Plastics offers a full range of plastic molding capabilities to efficiently mass-produce parts specializing in injection molding and have served customers in variety of industries such as medical, automotive, packaging, construction, home appliances , and agriculture. The company has two factories which occupy a total area of more than 18,000 square meters, and a total of 102 sets of injection molding machines .
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