Abstract:
A method and a machine account for changes in material properties of molten plastic material during an injection run. A change in a control signal is calculated by a controller during the injection molding run. If the change in the control signal indicates a change in material flowability, the controller alters a target injection pressure to ensure that molten plastic material completely fills and packs a mold cavity to prevent part flaws such as short shots or flashing.
Abstract:
A method and a machine that account for changes in material properties of molten plastic material during an injection run. If viscosity of the molten plastic material changes during an injection run, a controller alters a step time of the injection cycle to ensure that molten plastic material completely fills and packs a mold cavity to prevent part flaws such as short shots or flashing.
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:
A injection molding method involves measuring, using at least one strain gauge sensor, a change in strain in a mold side of a mold cavity, approximating a pressure within the mold cavity based on the change in strain, comparing the approximated pressure to a pre-set trigger point, and if the approximated pressure equals or exceeds the pre-set trigger point, activating a virtual cavity sensor having an optimal pre-defined pressure-time curve, wherein upon activation, the virtual cavity sensor tracks approximated pressures calculated from the change in strain measurements measured by the at least one strain gauge sensor over time and compares the results of the approximated pressure tracking to the optimal pre-defined pressure-time curve.
Abstract:
An injection molding machine that uses a mold and a native controller to operate according to an original mold cycle to mold plastic objects is retrofitted with a retrofit controller; the retrofitted machine uses the mold and the retrofit controller to operate according to a retrofit mold cycle to mold plastic objects. The retrofit mold cycle has a maximum injection pressure that is less than a maximum injection pressure of the original mold cycle. The retrofit mold cycle can also have more constant injection pressures than the original mold cycle.
Abstract:
An injection molding machine that uses a mold and a native controller to operate according to an original mold cycle to mold plastic objects is retrofitted with a retrofit controller; the retrofitted machine uses the mold and the retrofit controller to operate according to a retrofit mold cycle to mold plastic objects. When molding according to the retrofit mold cycle, the injection molding machine can obtain a faster cycle time.
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 low constant pressure injection molding machine forms molded parts by injecting molten thermoplastic material into a mold cavity at low constant pressures of 6,000 psi and lower. As a result, the low constant pressure injection molding machine includes a mold formed of easily machineable material that is less costly and faster to manufacture than typical injection molds.
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.