Precautions before injection mold trial

Release time:

2024-04-08

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In order to prevent the finished short shot, fracture, deformation, burrs and even damage to the mold. If the processing cycle is too short, the thimble will top through the finished product or the peeling ring will crush the finished product. This kind of situation may take you two or three hours to remove the finished product. If the processing cycle is too long, the weak part of the mold core may be broken due to the tightening of the rubber material. Of course, you can't predict all the problems that may occur during the trial process, but full consideration in advance and timely measures will help you avoid serious and expensive losses.

1. Understand the relevant information of the mold:
It is best to obtain the design drawing of the mold, analyze it in detail, and ask the mold technician to participate in the mold test work.
2. First check the mechanical coordination action on the workbench:
Attention should be paid to whether there are scratches, missing parts and looseness, whether the movement of the die to the sliding plate is true, whether the water channel and gas pipe joints leak, and whether the opening distance of the die is limited should also be marked on the die. If the above actions can be done before hanging the mold, it can avoid the waste of working hours caused by finding problems when hanging the mold and then disassembling the mold.
3. When determining the appropriate action of each part of the mold, it is necessary to select the appropriate test mold injection machine, in the selection should pay attention:
(a) What is the maximum injection volume of the injection molding machine
(B) Whether the inner distance of the tie rod is put into the lower die
(c) Whether the maximum movement travel of the activity template meets the requirements
(d) Whether other relevant tools and accessories for mold test are fully prepared
After everything is confirmed that there is no problem, the next step is to hang the mold. During hanging, attention should be paid not to take off the hanging before locking all clamping templates and opening the mold, so as to prevent the clamping templates from loosening or breaking and causing the mold to fall. After the mold is installed, the mechanical actions of each part of the mold should be carefully checked, such as the actions of the sliding plate, thimble, tooth withdrawal structure and limit switch. And pay attention to whether the injection nozzle is aligned with the feeding port.
The next step is to pay attention to the mold closing action. At this time, the mold closing pressure should be lowered. During the manual and low-speed mold closing actions, attention should be paid to see and listen to whether there are any phenomena such as unsmooth movements and abnormal sounds. The process of hoisting the mold is actually relatively simple. The main place that needs to be careful is that it is difficult to calibrate the mold gate and the nozzle. Usually, the calibration center can be adjusted by means of test paper.
4. Increase the mold temperature:
According to the performance of the raw materials used in the finished product and the size of the mold, the appropriate mold temperature control machine is selected to increase the temperature of the mold to the temperature required for production. After the mold temperature increases, the movement of each part must be checked again, because the steel may cause mold jamming after thermal expansion, so attention must be paid to the sliding of each part to avoid strain and vibration.
5. If the experimental planning rule is not implemented in the factory, we recommend that only one condition be adjusted at a time when adjusting the test conditions in order to distinguish the impact of a single condition change on the finished product.
6. According to different raw materials, appropriate baking shall be done for the raw materials used.
7. The same raw materials shall be used for trial mode and mass production in the future.
8. Do not test the mold completely with the second material. If there is a color requirement, you can arrange the color test together.
9. Internal stress and other problems often affect the secondary processing. After the mold is closed at a slow speed after the finished product is stable after the mold is tested, the mold closing pressure should be adjusted, and the mold closing pressure should be checked several times to see if there is any uneven mold closing pressure, so as to avoid burrs and mold deformation in the finished product.
After the above steps are checked, the mold closing speed and mold closing pressure will be lowered, and the safety buckle rod and ejection stroke will be set, and then the normal mold closing and mold closing speed will be adjusted. If the limit switch of the maximum stroke is involved, the mold opening stroke should be adjusted slightly shorter, and the high-speed mold opening action should be cut off before the maximum mold opening stroke. This is due to the fact that the high-speed action stroke is longer than the low-speed one during the whole mold opening stroke during mold loading. The mechanical ejection rod on the plastic machine must also be adjusted to act after the full-speed mold opening action to prevent the thimble plate or stripping plate from being deformed by force.
Please check the following items again before making the first mold injection:
(a) Whether the feeding stroke is too long or insufficient.
(B) Whether the pressure is too high or too low.
(c) Whether the filling speed is too fast or too slow.
(D) Whether the processing cycle is too long or too short.
In order to prevent the finished short shot, fracture, deformation, burrs and even damage to the mold. If the processing cycle is too short, the thimble will top through the finished product or the peeling ring will crush the finished product. This kind of situation may take you two or three hours to remove the finished product. If the processing cycle is too long, the weak part of the mold core may be broken due to the tightening of the rubber material. Of course, you can't predict all the problems that may occur during the trial process, but full consideration in advance and timely measures will help you avoid serious and expensive losses.