Abstract:
Injection molding at substantially constant pressure yields a substantially controlled injection molding process, even when utilizing a leaking check ring.
Abstract:
A system for forming a plastic article, the system comprising a preform injection molding apparatus, comprising a mold, a plastic melt injection system, a sensor, and a controller, wherein: the first mold portion is made of a material having a thermal conductivity between about 52 watts per meter kelvin and about 385 watts per meter kelvin; the controller is configured to control the injection element to maintain the molten thermoplastic material at a substantially constant melt pressure, during filling of the mold cavities, wherein the substantially constant melt pressure is between about 2.76 megapascals (400 psi) and about 68.95 megapascals (10,000 psi); and the preform injection molding apparatus is designed to have a useful life of between one million and ten million injection molding cycles.
Abstract:
A feed system for an injection molding machine. The feed system includes a first part with a first channel, and a second part with a second channel. The first channel and the second channel together form a molten plastic feed conduit when they are engaged. The first part and the second part are unbonded to one another.
Abstract:
A feed system for an injection molding method and machine includes a first part including a first channel, and a second part including a second channel, the first channel and the second channel forming a molten plastic feed conduit when the first part is located adjacent to the second part. A joint is formed between the first part and the second part along the first channel and the second channel and the joint is one of a sintered joint, a welded joint, and a brazed joint.
Abstract:
A method of forming a preform, which is configured to be subjected to a subsequent forming process, the method comprising: providing a mold with a plurality of mold cavities, wherein the mold is made of a material having a thermal conductivity between about 52 watts per meter Kelvin and about 385 watts per meter Kelvin.
Abstract:
A carousel-like continuous molding system includes an arrangement of inclined feed channels. Each of the feed channels has a controllable valve therein positioned upstream of an inlet to an associated mold cavity. The valve is controllable so that adjustments may be made in real time to achieve or maintain delivery of molten polymeric material to the mold cavity at constant pressure.
Abstract:
Injection molding at substantially constant pressure with the use of rapid heating techniques, such as induction heating, at strategic locations within a mold to heat molding surfaces in a manner that mitigates problems typically associated with flow filling challenges.
Abstract:
A carousel-like continuous co-injection molding system includes an arrangement of upper and lower inclined feed channels. Each of the feed channels has a valve therein positioned upstream of an inlet to an associated mold cavity. The valve is controllable so that adjustments may be made in real time to achieve or maintain delivery of molten polymeric material to the mold cavity at constant pressure.
Abstract:
In order to injection mold parts at a constant flow front velocity in a mold cavity of an injection molding system, particularly where the mold cavity has a varying thickness along its length, mold modeling software is used to calculate the cross-sectional area as a function of the distance from the gate, percentage of fill, or length of the mold cavity. Based on that cross-sectional area, the mold modeling software determines an appropriate recommended ram force profile and/or melt pressure profile that would result in filling the mold cavity at a constant flow rate. An injection molding system is then operated according to the recommended ram force profile and/or melt pressure profile.