New mold injection molding before, or machine replacement of other mold production, the test mode is an essential part. If the test results are good or bad, it will directly affect the subsequent production of the factory is smooth. Therefore, it is necessary to follow the reasonable operation steps and record the useful technical parameters during the test mode to facilitate the mass production of the products.
First, try before the precautions
1. understand the mold of the relevant information
It is best to get the mold design drawings, detailed analysis, and about the mold technician to participate in the test work.
2. Check the mechanical fit on the workbench
Should pay attention to whether the scratches, missing parts and loosening and other phenomena, mold to the slide action is true, 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 the hanging mode, you can avoid the problem when the die, and then go to the demolition of the mold occurred in the waste of time.
3. When the mold to determine the appropriate action, we must choose the appropriate test machine injection molding machine, in the choice should pay attention to:
(1) the maximum injection rate of injection molding machine is how much;
(2) whether the rod is placed under the mold;
(3) whether the maximum movement stroke of the activity template meets the requirements;
(4) other related test tools with tools and accessories are prepared.
Everything is confirmed no problem, Injection mold then the next step is to hang mold. Suspension should be noted that all the folder before locking the template and open the mold before the hook should not be removed, so as not to loose or loose folder template die so die.
After the mold is installed, it should carefully check the mechanical parts of the mold parts, such as skateboard, thimble, retreat structure and limit the action of the switch is true, and pay attention to the nozzle 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, pay attention to see if there is any smooth action and abnormal sound and so on. Injection mold Lifting mold process is relatively simple, need to carefully place the main mold gate and nozzle adjustment center is more difficult, usually can be used to test the way the center of the test paper.
4. Increase the mold temperature
Depending on the performance of the raw materials used in the product and the size of the mold, use the appropriate mold temperature control machine to increase the temperature of the mold to the temperature required for production. After the mold temperature is raised, the action of each part must be examined again, because the steel may cause the punching phenomenon due to the thermal expansion. Therefore, Injection mold it is necessary to pay attention to the sliding of each part so as to avoid the occurrence of strain and vibration.
5. If there is no implementation of the experimental plan in the factory, it is recommended to adjust the test conditions, one can only adjust a condition in order to distinguish between a single condition changes on the impact of the 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 material, 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 mode, to be stable products, that is, to be secondary processing mold. In the slow after the close, to adjust the clamping pressure, and action several times to see whether the phenomenon of unequal clamping pressure, so as to avoid the products produce flash and die deformation.
After the above steps are checked, and then turn off the speed and off the mold pressure down, and the safety buckle and the trip out of the trip, and then transferred to the normal off mode and off mode speed. 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 because during the mold, the entire opening stroke, Injection mold the high-speed action travel longer than the low speed. In the plastic machine, the mechanical top rod must also be transferred in full-speed mode after the action, so that the thimble or peel plate force and deformation.
Before making the first mold, check the following:
(1) whether the feeding stroke is too long or insufficient;
(2) whether the pressure is too high or too low;
(3) whether the filling speed is too fast or too slow;
(4) whether the processing cycle is too long or too short.
To prevent the product short shot, broken, deformation, burr and even hurt the mold. If the processing cycle is too short, the thimble will wear the top product or stripping the product, this situation may make you spend two or three hours to remove the product. If the processing cycle is too long, the thin parts of the core may be cut off due to shrinkage. Of course, you can not anticipate any possible problems with the trial process, Injection mold but it is important to take full account of and take timely measures to help you avoid serious and expensive losses.
Second, 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, The working method.
1. Check whether the plastic in the cartridge is correct and whether it has been baked in accordance with the regulations (it is likely that different results will be obtained if the mold is produced with different raw materials).
2. Clean the pipe to thoroughly, to prevent the deterioration of the compound or miscellaneous materials into the mold. Because the bad solution and miscellaneous materials may die stuck die. Check the temperature of the pipe and the temperature of the mold is suitable for the processing of raw materials.
3. Adjust the pressure and the amount of injection in order to produce a satisfactory appearance of the product. But can not run burr, especially when there are some mold cavity products have not yet fully solidified. Before you adjust the various control conditions, think about it, because the filling rate changes slightly, may cause a lot of 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 view the product may be problems.
5. Screw forward time can not be shorter than the gate plastic solidification time, otherwise, the weight of the product will be reduced, Injection mold and damage the performance of the product. And when the mold is heated, the screw forward time also need to be lengthened in order to compaction products.
6. Reasonable adjustment to reduce the total processing cycle.
7. Run the newly recalled condition for at least 30 minutes and stabilize, and then at least continuously produce a full-blown sample, mark the date, quantity, and place in the course of the platoon, in order to test the stability of its operation And derive reasonable control tolerances (especially for multi-pocket 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,
(1) whether the product size is stable;
(2) whether the size of some of the increase or decrease in the trend, while the display machine processing conditions are still changing, such as poor temperature control or hydraulic control;
(3) whether the size of the changes within the tolerance range.
10. If the size of the product is no longer changing and the processing conditions are normal, it is necessary to observe whether the quality of the product of each mold cavity is acceptable and its size can be within the allowable tolerances. Injection mold 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.