When we receive a new mold to test proof, we always eager to try out some of the results earlier and pray process smoothly to avoid wasting hours and causing trouble.
But here we have to remind two points:
First, the mold designer and manufacturing technician sometimes mistakes, in our test mode if not vigilant, may be due to small errors and cause great damage.
Second, the test results is to ensure that the subsequent production of the smooth. If the test process did not follow the reasonable steps and do the appropriate records, that is, can not guarantee the smooth progress of mass production. We are more stressed that "the use of smooth mold will quickly increase the profit recovery, or the cost of the loss will be even more than the cost of the mold itself."
Second, try before the precautions
1, to understand the mold of the relevant information
It is best to obtain the design of the mold surface, detailed analysis, and about the mold technician to participate in the test work.
2. First check the work on the table with the mechanical action:
Should pay attention to whether the scratches, missing parts and loosening phenomenon, mold to the skateboard action is indeed, whether the waterway and tracheal joints leak, mold opening if the restrictions should also be marked on the mold. If the above action can be done before hanging in the mold, you can avoid the problem in the hanging mold, go to the demolition of the mold occurred when the waste.
3. When the mold to determine the appropriate action, we must choose the appropriate test mode injection machine, in the selection should pay attention
(A) Injection capacity
(B) the width of the guide bar
(C) the largest opening
(D) accessories
Whether it is complete and so on. Everything is confirmed no problem after the next step is to hang the mold, hanging should pay attention to all the folder on the lock template and open the mold before the fishing do not remove, so as not to loose or loose template so die die.
After the mold is installed, please carefully check the mechanical parts of the mold parts, such as skateboard, thimble, retreat structure and limit the action of the switch is true. Mold master micro letter: 1828765339 and pay attention to the mouth of the feed and the inlet is aligned. The next step is to pay attention to the clamping action, this time should be down the mold pressure, in the manual and low-speed mold clamping action to see if there is any smooth action and abnormal sound and so on.
4. Increase the mold temperature:
Depending on the performance of the finished product and the size of the mold, the appropriate temperature control machine is used to increase the temperature of the mold to the temperature required for production.
As soon as the mold temperature is increased, the action of each part must be examined again. Since the steel may cause the punching phenomenon after thermal expansion, it is necessary to pay attention to the sliding of the parts so as to avoid strain and vibration.
5. If there is no implementation of the experimental plan in the factory, we recommend that only one condition can be adjusted at one time in order to distinguish the impact of a single conditional change on the finished product
6. According to the different materials, the original used to make a moderate baking.
7. Try to mold with the future production as much as possible using the same raw materials.
8. Do not completely test the mold, if the color needs, can be arranged together try color.
9. Internal stress and other issues often affect the secondary processing, should be after the test model to be finished after the stability of the secondary processing mold in the slow after the close, to adjust the mold pressure, and action several times to see if Mold pressure uneven phenomenon, so as to avoid the finished product and mold deformation.
After the above steps are checked and then turn off the mold speed and shutdown mode pressure down, and the safety buckle and the trip out of the trip set, and then transferred to the normal off mode and off mode speed. Die people magazine micro - letter dedicated service mold people. If the limit switch for the maximum stroke is involved, the opening stroke should be adjusted slightly and the high speed open operation is cut off before the maximum stroke is opened. This is due to the mold during the entire mold during the trip, the high-speed action stroke longer than the low speed. In the plastic machine on the mechanical ejector rod must also be transferred in full-speed mode after the action, so that the top plate or stripping plate force and deformation.
Please check the following before making the first mold:
(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.
To prevent the finished product short shot, broken, deformation, burr and even hurt the mold.
If the processing cycle is too short, the thimble will wear the finished product or stripping the finished product. This may cause you to spend two or three hours to remove the finished product.
If the processing cycle is too long, the mold core of the delicate parts may be due to shrinkage and cut off the material.
Of course, you can not anticipate all the problems that may occur in the trial process, but the prior precautions to be taken in a timely manner will help you avoid serious and expensive losses.
Third, try the main steps
In order to avoid unnecessary waste of time and trouble, it is necessary to pay patience to adjust and control a variety of processing conditions, and to find the best temperature and pressure conditions, and the development of standard test procedures, and can be used for Establish daily work methods.
1. Check whether the plastic material in the cartridge is correct and whether it has been baked in accordance with the regulations (it is possible to produce different results if the mold is produced with different raw materials).
2. The pipe is cleaned thoroughly so as to prevent the breakage of the compound or miscellaneous material into the mold, as the inferior solution and the miscellaneous material may be the mold card. The temperature of the test tube and the temperature of the mold are suitable for the raw material for processing.
3. Adjust the pressure and the amount of injection in order to produce a satisfactory appearance of the finished product, but can not run the edge, especially when there are some mold cavity finished product has not yet fully solidified, in the adjustment of various control conditions should be considered before, because the filling A slight change in the rate may cause very large filling changes.
4. To wait until the conditions of the machine and die stabilized, that is, medium-sized machines may have to wait more than 30 minutes. You can use this time to see the finished product may occur.
5. Screw forward time can not be shorter than the gate plastic solidification time, otherwise the finished product weight will be reduced and damage to the finished product performance. And when the mold is heated when the screw forward time also need to lengthen in order to compact the finished product.
6. Reasonable adjustment to reduce the total processing cycle.
7. Run the newly recalled conditions for at least 30 minutes to stabilize, and then at least continuously produce a dozen full-size samples, mark the date, quantity, and place them in the course of the cages to test their stability And derive reasonable control tolerances. (Especially valuable for multi - hole molds).
8. Measure the continuous sample and record its important dimensions (wait for the sample to cool to room temperature).
9. Make a comparison of the size of each sample,
(A) size is stable.
(B) whether there is any increase or decrease in the size of the trend shows that the machining conditions are still changing, such as poor temperature control or hydraulic control.
(C) whether the change in size is within the tolerance.
10. If the finished product size does not change and the processing conditions are normal, it is necessary to observe whether the finished product of each mold cavity is acceptable and its size can be within the tolerances. The amount of continuous or large or less than the average value of the mold points recorded in order to check the size of the mold is correct.
Record and analyze the data as a need to modify the mold and production conditions, and for future production reference.
1. To make the operation run longer, to stabilize the melt temperature and hydraulic oil temperature.
2. According to all the size of the finished product is too large or too small to adjust the conditions of the machine, if the shrinkage is too large and finished products appear insufficient material, but also reference to increase the gate size.
3. If the size of the mold is too large or too small to be amended, if the mold cavity and the door size is correct, then you should try to change the machine conditions, such as filling speed, mold temperature and pressure, Whether the filling is slow.
4. According to the combination of the mold cavity of the finished product or mold core shift, to be individually amended, may be able to try to adjust the mold speed and mold temperature, in order to improve its uniformity
5. Check and modify the failure of the injection machine, such as pumps, oil valves, temperature controller, etc. will lead to changes in processing conditions, even if the mold can not improve the bad machine to play a good record of all the recorded value, Keep a set of samples for proofreading.
Fourth, important matters
Keep all records of the test in the course of the test, including the various pressures of the processing cycle, the temperature of the melt and the mold, the temperature of the tube, the time of injection, the time of the screw feeding, etc., in short, Can successfully establish the same processing conditions of the data, in order to obtain quality standards of the product.
At present, the factory test mode often overlooks the mold temperature, and in the short test mode and the future production mold temperature is the most difficult to grasp, and the correct mold temperature enough to affect the sample size, luminosity, shrinking, , If you do not use the mold temperature controller to grip when the future production may be difficult.