Injection Molding Learning

- Dec 19, 2018-

6. Calculate residence time and importance


As a general rule, the residence time of a plastic on a particular injection molding machine should be calculated. Especially when a large injection molding machine uses a small amount of shot material, the plastic is easily decomposed, which is not detectable from observation. If the residence time is short, the plastic will not be plasticized evenly; the retention time will be attenuated by the plastic properties. Therefore, it is necessary to maintain the same residence time.


Method: Ensure that the plastic input into the injection molding machine has a stable composition, consistent size and shape. If there is any abnormality or loss of the parts of the injection molding machine, it must be reported to the maintenance department.


7. Shooting tank temperature environment


It should be noted that the melt temperature is important and any shot cylinder temperature used is only indicative. If you have not experienced the processing of a particular plastic, start with the lowest setting. Usually the temperature in the first zone is set to the lowest value to prevent premature melting and blocking of the plastic in the feed port.


The temperature in the other zones then gradually increases until the nozzle is reached, and the temperature at the tip of the nozzle tends to be slightly lower to prevent dripping. The mold is also heated and cooled. Due to the size relationship of many molds, the mold is also distinguished, but unless otherwise stated, the zones should be set to the same size.