Before the injection molding of new mold or when the machine changes other mold for production, mold testing is an essential part. The result of mould test will directly affect the follow-up production of the factory. Therefore, it is necessary to follow the reasonable operation steps and record the useful technical parameters in the process of mold test in order to facilitate the mass production of products.
Precautions before mold test
1. Understand the relevant information of the mold:
It is better to get the design drawing of the mould, analyze it in detail, and invite the mould technician to participate in the mould test.
2. Check the mechanical cooperation action on the workbench first:
Pay attention to whether there are scratches, missing parts, looseness and other phenomena, whether the mold moves towards the sliding plate truly, whether there is leakage at the water channel and air pipe joint, and if there is any limit on the opening of the mold, it shall also be indicated on the mold. If the above actions can be done before die hanging, problems can be avoided during die hanging, and then the waste of working hours occurred during die dismantling can be avoided.
3. After determining the proper action of each part of the mold, it is necessary to select a suitable testing injection machine. Attention shall be paid to the following when selecting:
(a) What is the maximum injection volume of injection molding machine
（b） Whether the internal distance of pull rod is placed on the lower mold
(c) Whether the maximum travel distance of the movable template meets the requirements
(d) Whether other tools and accessories for mold test are complete
After everything is confirmed to be OK, the next step is to hang the mold. During hanging, pay attention not to take off the hook before locking all clamping formworks and opening the mold, so as to avoid the mold falling due to the loosening or fracture of clamping formworks. After the mold is installed, carefully check the mechanical action of each part of the mold, such as the action of sliding plate, thimble, tooth withdrawal structure and limit switch. And pay attention to whether the injection nozzle is aligned with the feed inlet. The next step is to pay attention to the mold closing action. At this time, the mold closing pressure should be reduced. In the manual and low-speed mold closing action, pay attention to see and hear whether there are any non smooth actions and abnormal sounds. In fact, the process of lifting the mold is relatively simple. The main thing that needs to be careful is that it is difficult to calibrate the center of the mold gate and nozzle. Usually, the test paper can be used to calibrate the center.
4. Increase mold temperature:
According to the properties of the raw materials used in the finished product and the size of the mold, select the appropriate mold temperature control machine to raise the temperature of the mold to the temperature required for production. After the mold temperature is increased, the action of each part shall be inspected again. Because the steel may cause clamping phenomenon after thermal expansion, it is necessary to pay attention to the sliding of each part to avoid the occurrence of strain and vibration.
5. If there is no experimental planning rule in the factory, we suggest that only one condition can be adjusted at a time when adjusting the test conditions, so as to distinguish the impact of single condition change on the finished product.
6. According to different raw materials, bake the raw materials properly.
7. Try to use the same raw materials as the mass production in the future.
8. Do not test the mold completely with secondary materials. If there is color demand, color test can be arranged together.
9. Internal stress and other problems often affect the secondary processing. After the mold is tested and the finished product is stable, the secondary processing mold should be used. After the mold is closed slowly, the mold closing pressure should be adjusted and operated several times to check whether there is any mold closing pressure inequality, so as to avoid rough edge and mold deformation of the finished product.