Interpretation of professional terms for positive and negative pressure sheet forming machines - 8 times, including: heating time, running cycle, negative pressure time, positive pressure time, setting time, blowing time, delay time, sheet feeding time, etc.
1. Heating time. It is the time that the sheet stays in the electric furnace. Generally, the forming machine is heated in three stages. For example, if the running cycle is 3 seconds, the sheet needs to stop three times from entering the electric furnace to the electric furnace, and heating for 3 seconds each time, then the total time That's 9 seconds. The length of the heating time depends on the material and thickness of the sheet, the temperature of the electric furnace and the time of the operation cycle. Generally speaking, the thicker the sheet, the longer the heating time is, and the higher the temperature of the electric furnace, the shorter the heating time. In actual production, in order to increase the production capacity, the commissioning principle is to use a higher heating temperature to shorten the heating time, so as to speed up the operation cycle time and achieve the production capacity of the equipment.
2. Run cycle. It refers to the sum of the time from mold clamping, positive and negative pressure forming, cooling and setting, blowing off the mold, and chain sending. Generally, the running cycle of the machine can be very fast, which will be less than the heating time. Therefore, when the heating time cannot be shortened, the running cycle time is equivalent to the heating time.
3. Negative pressure time. It refers to the time from the start of vacuuming to the end of vacuuming after the mold is closed. Because there is a time process for mold closing, vacuuming generally requires a delay. In principle, the negative pressure time should be as long as possible, which is beneficial for the sheet to stick to the mold and facilitate the rapid cooling and shaping of the product.
4. Positive pressure time. Compressed air is much larger than vacuum pressure, so positive pressure is more conducive to product forming, which can indirectly reduce the heating temperature, reduce the burden of cooling water, and will not affect the heating time of the sheet. Generally, the start time of positive pressure is later than the negative pressure time, and the end time is earlier than the negative pressure time, which plays the role of high pressure forming, shaping and cooling in the middle.
5. Setting time. It refers to the time for the product to be cooled and shaped in the mold after being formed by positive and negative pressure in the mold. The length of the setting time depends on the temperature of the mold, the size and thickness of the product. To obtain a product with a qualified shape, cooling and setting play a key role. Generally speaking, the time should not be too short. A lower cooling water temperature can shorten the setting time of the product, but if the mold temperature is too low, it will also cause the product to shrink too quickly and produce cooling marks, so reasonable mold temperature control is particularly important.
6. Blow off time. Also called air ejection time. When the mold is opened, the vacuum is quickly switched to positive pressure, which plays the role of breaking the vacuum, and it also gives the product a blowback force through the exhaust hole, which can prevent the mold from sticking and help the product to be demolded.
7. Delay time. All the actions of the multi-station are based on the stop and go of the chain. By setting the delay time of each action, there will be morning and evening, and good coordination of actions will be achieved, so as to obtain good products.
8. Film delivery time. It is the time for the chain to move. After one mold is completed, the chain drives the sheet to the next mold, and the cycle starts and ends. The length of the feeding time depends on the length of the die width. The faster the chain rotates, the shorter the feeding time.
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