In general, at the time of mold design, the weight of the product is calculated by the software, even if there is an error. So how do you convert the screw movement interval into the machine?
Formula: screw movement interval = product accounting component / screw cross-sectional area / plastic density plastic / compensation coefficient
Case: The theoretical value of the product is 200g, with a machine of 280 tons, the diameter is 50mm, the density of the PS material is 1.05, and the compensation coefficient is 0.85.
Then the screw movement interval = 200 / (2.5 * 2.5 * 3.14) / 1.05 / 0.85 = 11.4 cm
This is the final total screw movement interval, then according to the actual situation, if it is the mold structure promise, the list can shoot 50% full and move 5cm for the first time. If the mold structure needs to be fully filled, then it will shoot more than 10cm. Look like. Reply "Injection" and check more
A few minor issues:
First: the compensation coefficient is the difference between the density of the plastic at room temperature and the material actually used in the barrel. The actual material used in the barrel will be less, mainly due to the volume expansion of the plastic after melting, the counterflow of the screw, and the leakage of the screw. When it is caused, it usually takes between 0.80 and 0.90.
Second: If the list is to be full of shots for the first time, you must pay attention to the direction of low-voltage switching to avoid explosion or approval.
Third: the mold temperature at the time of the test must be equal to the temperature at the time of mass production, the mold temperature is different, the glue interval is very different, the same temperature PP, the mold cavity in 20 degrees and the mold cavity of 80 degrees In the activity, the gap between the activities of the same component will reach more than 15%, so we must pay attention to the stability of the mold temperature.
In the end, the plastic mold injection parameters should be scientifically managed, and the accurate accounting of the parameters, not just the feeling is the first step of scientific management.