| 摘要 |
<p>METHOD OF INJECTING PLASTIC MATERIAL USING A PLASTIC INJECTION MACHINE A method of injecting plastic material into the cavity of a mold is disclosed which method is particularly useful for the injection of foam-type plastics and/or the injection into a mold cavity which contains certain fill pieces, inserts or the like, which may be moved or disturbed in their position by high pressure injection. The method includes the prepressurization of the plastic material within the injection cylinder to a relatively low pressure, opening the nozzle valve on the cylinder at the conclusion of the very short time interval and injecting the plastic material at the low pressure over a second time interval to effect a controlled injection of the plastic material. After the material has been injected, a third time interval is established throughout which a substantially higher pressure is applied to the plastic material to set up the foam material, to provide a uniform homogeneity of the product, and to insure complete and full filling of the mold without disturbing any delicate inserts which may have been within the mold cavity.</p> |
