Abstract:
Injection molding at substantially constant pressure yields a substantially controlled injection molding process, even when utilizing a leaking check ring.
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:
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.
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 melt pressure regulating mechanism for an injection molding apparatus having a melt holder for pressurizing molten plastic prior to injection into a mold, the molten plastic having a melt pressure, and an injection element for advancing the molten plastic from the melt holder through a nozzle and into the mold, the melt pressure regulating mechanism comprising a pressure regulating device, comprising at least one of a fluid pressure regulating valve and a pressure relief valve.
Abstract:
A method of detecting and compensating for a non-operational mold cavity in an injection molding apparatus having a plurality of mold cavities and an injection molding screw or ram includes injecting, via the injection molding screw or ram, a molten thermoplastic material into the plurality of mold cavities. The method includes measuring a first process parameter of the injection molding apparatus at a pre-determined time during or after the injecting. The method also includes determining, based on the first process parameter, whether one or more mold cavities of the plurality of mold cavities are non-operational. Then, when it is determined that one or more mold cavities are non-operational, the method includes automatically adjusting the first process parameter or a second process parameter of the injection molding apparatus.
Abstract:
Systems and approaches for controlling an injection molding machine and a mold forming a mold cavity and being controlled according to an injection cycle. The systems and methods include analyzing a model of at least one of the injection molding machine, the mold, and a molten material to determine initial values for one or more control parameters of the injection molding machine, and executing a run of injection cycles at the injection molding machine; measuring operation of the injection molding machine during a particular injection cycle of the run of injection cycles; determining one or more operational parameters exceed a threshold; and upon determining that the one or more operational parameters exceed the threshold, adjusting the one or more control parameters for subsequent injection cycles of the run of injection cycles.
Abstract:
A method and system for co-injection molding of two molten plastic materials that allows monitoring and utilization of injection pressure and optionally melt pressure and/or flow front pressure during an injection run. A controller alters the injection pressure so as to achieve and maintain optimal or desired ratios of injection pressure, and optionally melt pressure and/or flow front pressure, of the two molten plastic materials. This allows for more precise part manufacture, including reducing the thickness of a skin or shell layer compared to a core layer of a molded part.
Abstract:
Embodiments within the scope of the present disclosure are directed to external sensor kits that may be included in new injection molds or retrofitted into existing injection molds in order to approximate conditions within a mold, such as pressure or the location of a melt flow front. Such kits are designed to amplify meaningful measurements obtained by the external sensor kit so that noise measurements do not prevent the approximation of conditions within a mold. In some embodiments within the scope of the present disclosure, an external sensor kit includes a strain gauge sensor, a coupon, a support bracket, and a hammer. The strain gauge sensor is placed on a surface of the coupon and measures the strain in the coupon.
Abstract:
Systems and approaches for controlling an injection molding machine having a mold forming a mold cavity and being controlled according to an injection cycle include obtaining a pattern for the injection cycle, operating the injection molding machine to inject a molten material into the mold cavity , and measuring a cavity pressure value of the mold cavity during the mold cycle. Upon measuring a nominal cavity pressure value, a pattern recognition portion of the injection cycle that is at least partially dependent on the obtained pattern commences where a driving force being exerted on the molten material is adjusted such that the measured cavity pressure matches the obtained pattern for the injection cycle.