1. Understand relevant information of mold:
It is best to get design drawing of mold, analyze it in detail, and get mold maker to participate in mold trial work.
2. Check mechanical coordination action on workbench:
Pay attention to whether there are any scratches, missing parts and looseness, whether mold-to-slide action is correct, whether there is leakage in water pipe and gas pipe joint, if opening of mold is restricted and it should be marked on mold. If above actions can be done before mold is hung, it is possible to avoid finding problem when mold is hanging, and waste of work caused by disassembling mold.
3. When it is determined that all parts of mold are suitable for movement, it is necessary to select a suitable test injection machine. When selecting, pay attention to whether opening accessories with the largest width of injection guide are complete. After everything is confirmed to be no problem, next step is to hang mold. When hanging, pay attention to all clamp templates and hanging fishing before mold is opened, prevent template from loosening or breaking, causeing mold dropped.
After mold is installed, mechanical action of each part of mold should be carefully checked, such as skateboard, thimble, retracting structure and limit switch. Also pay attention to whether nozzle and feed port are aligned. Next step is to pay attention to mold clamping action. At this time, mold closing pressure should be lowered. In manual and low speed mold clamping operation, pay attention to whether or not there is any smooth movement and abnormal sound.
4. Increase mold temperature:
According to performance of raw materials used in finished product and size of mold, an appropriate mold temperature control machine is used to raise temperature of mold to temperature required for production. After mold temperature is increased, movement of each part must be reviewed again, because steel may cause jamming after thermal expansion, so it is necessary to pay attention to sliding of each part to avoid occurrence of strain and chatter.
5. If there is no experimental plan in mold factory, we recommend that only one condition can be adjusted at a time when adjusting test conditions to distinguish impact of a single condition change on finished product.
6. Depending on raw materials, make a proper baking of original used.
7. Try and use same raw materials as much as possible in future mass production.
8. Do not try test by default. If there is any color requirement, can arrange test color together.
9. Internal stress and other problems often affect secondary processing. After test is finished, finished product is stabilized and secondary processing die is placed at a slow speed. After mold is closed, mold pressure should be adjusted and movement should be performed several times to check whether there is uneven clamping pressure, so as to avoid production of burrs and mold deformation.
After above steps are checked, mold closing speed and closing pressure are lowered, safety buckle and ejection stroke are set, normal closing mode and closing speed are adjusted. If limit switch involving maximum stroke is involved, mold opening stroke should be adjusted slightly shorter, high speed mold opening action should be cut off before maximum stroke of mold opening.
This is because during entire mold opening stroke and mold clamping, high speed stroke is longer than low speed. Mechanical ejector rod on plastic machine must also be adjusted to act after full-speed mold opening action to prevent ejector plate or peeling plate from being deformed by force.

 

Please check following items before making the first shot with mold factory:
Whether feeding schedule is too long or insufficient.
Whether pressure is too high or too low.
Whether filling speed is too fast or too slow.
Whether processing cycle is too long or too short.
To prevent short shots, breakage, deformation, burrs and even damage to mold.
If processing cycle is too short, thimble will pierce or strip finished product. This type of situation may take you two or three hours to remove finished product.
If processing cycle is too long, weak part of mold core may be broken due to shrinkage of rubber.
Of course, you can't predict all problems that may occur during mold trial process, but taking precautions and taking timely measures will help you avoid serious and expensive losses.

In order to avoid unnecessary waste of time and trouble during mass production, it is necessary to patience to adjust and control various processing conditions, find best temperature and pressure conditions, develop standard test procedures, and can be used to establish daily work methods.
1. Check whether plastic material in barrel is correct and whether it is baked according to regulations. (It is possible to obtain different results if different materials are used in mold trial and production).
2. Cleaning of material pipe should be thorough, in order to prevent inferior rubber or miscellaneous materials from being injected into mold, because inferior rubber and miscellaneous materials may cause mold to be stuck. Whether temperature of test tube and mold are suitable for raw materials to be processed.
3. Adjust pressure and amount of injection to produce a finished product with satisfactory appearance, but do not when there are burrs, especially when some cavity products are not fully solidified, you should think about it before adjusting various control conditions. A slight change in rate may cause a large change in filling.
4. Be patient and wait until conditions of machine and mold are stable, that is medium-sized machine may have to wait for more than 30 minutes. This time can be used to see what can happen to finished product.
5. Advancement time of screw should not be shorter than time plastic of gate is solidified, otherwise weight of finished product will decrease and performance of finished product will be damaged. When mold is heated, screw advance time also needs to be lengthened to compact finished product.
6. Reasonable adjustment to reduce total processing cycle.
7. Run newly transferred conditions for at least 30 minutes to stabilize, then at least continuously produce a dozen full-mode samples, mark date and quantity on holder, place them separately according to cavity to test stability of operation, derive reasonable control tolerances. (especially valuable for multi-hole molds).
8. Measure and record continuous size of continuous sample (should be re-sampled when sample is cooled to room temperature).
9. Compare dimensions of each model sample and note that:
Is size stable? Is there a tendency for certain dimensions to increase or decrease to indicate that machine processing conditions are still changing, such as poor temperature control or oil pressure control. Whether change in size is within tolerance range.
10. If finished product size does not change and processing conditions are normal, it is necessary to observe whether quality of each finished product of cavity is acceptable, and size can be within tolerance. Make a note of number of holes that are continuously large or smaller than average to check if size of mold is correct.

 

As a need to modify mold and production conditions, and for future production basis.
1. Make processing run time longer to stabilize melt temperature and hydraulic oil temperature.
2. According to size of all finished products is too large or too small to adjust machine conditions, if shrinkage rate is too large and finished product appears to be insufficient, it can also be used to increase gate size.
3. If size of each cavity is too large or too small, it should be corrected. if dimensions of cavity and door are correct, then correct machine conditions, such as filling rate, mold temperature and pressure of each part, and check whether some cavity is filled slowly.
4. According to matching situation of finished cavity products or displacement of mold core, correction may be made separately, mold filling rate and mold temperature may be tried again to improve uniformity.
5. Check and modify fault of injection machine. If oil pump, oil valve, temperature controller, etc. are bad, processing conditions will change. Even perfect mold can not work well in poorly maintained machine.
After reviewing all recorded values, a set of samples is retained to proofread whether corrected samples have improved.

Properly keep records of all sample inspections during test process, including various pressures during processing cycle, melt and mold temperatures, tube temperature, injection action time, screw feed period, etc. In short, all future contributions should be saved by mold factory. It is possible to successfully establish data on same processing conditions in order to obtain products that meet quality standards.
At present, mold temperature is often neglected during mold trial by mold factory, and mold temperature is the most difficult to master in short-term mold trial and future mass production. Incorrect mold temperature is enough to affect sample size, luminosity, shrinkage, flow pattern and material loss. If mold temperature controller is not used to master, for future mass production, there may be difficulties in mass production in the future.