1. The external cooling method is the earliest application method. Under the action of the cooling ring, the cooling air is released from a circular ring along the extrusion direction and the outer surface of the bubble to generate uniform cooling air around the ring. Inside the cooling ring, the air at the upper port is discharged at a faster average speed than that on the lower port. It is ensured that the shape of the film bubble is consistent with the air cooling ring, so that the average flow velocity of the air increases and therefore the heat transfer is improved.
2. The internal cooling directly passes through the film bubble to dissipate heat to achieve the purpose of cooling. Because the flow rate of the air in the bubble is relatively low and has no regularity, external cooling is more dominant. In the blowing process of the film blowing machine, in order to ensure the quality of the film product, the stability of the bubble before the film is formed must be considered, so that the qualified rate of the product can be effectively controlled. The output of blown film of the film blowing machine is not only restricted by the film bubble, but also the cooling system of the film blowing machine. A complete cooling system requires reasonable configuration and stability of the film blowing machine.
Daily inspection and maintenance of film blowing machine:
1. Check whether the temperature automatic control is intact, whether the heating appliances are intact, and pay attention to timely adjust the heating temperature of each node within the index range.2. Check the traction speed and control the film thickness.
3. Observe and adjust the uniformity of the film thickness, and the folding diameter meets the standard.4. Check the air storage cylinder pressure, it can not be too high, but there should be a backup pressure.
5. Check and control the ratio of raw materials and mix them evenly.6. Check that the raw materials are free of impurities, especially if the iron is mixed in with a magnet in time.
7. Check the lubrication of the gearbox position and the air compressor cylinder.
8. Regularly check the temperature rise and mechanical transmission of each running motor.