A process is provided for making a walled structure using an injection molding apparatus. The apparatus has a molding space formed between a mold cavity and an inner core disposed within the mold cavity. The molding space defines a shape of the structure. The process includes injecting molding material into the molding space, moving or retaining a portion of a movable impression member protruding from the inner core within a portion of the molding space so as to create a recess within an inner wall of the structure, and retracting the impression member into the inner core such that the impression member is cleared from the molding space. Precision control in forming the impression member is provided by a closed-loop configuration using a sensor that measures a molding space parameter (e.g., temperature), optionally in combination with a servo drive for activating the impression member.

A mold test apparatus includes a mold support plate having a top surface on which a mold is mounted, wherein the mold support plate includes a plurality of test suction pipes communicating with paths in the mold, vacuum pipes each having one end connected to one of the plurality of test suction pipes, a pump connected to the other end of the pipe, and at least one pressure sensor configured to measure a pressure of the vacuum pipe, wherein the paths communicate with adsorption holes provided in a top surface of the mold, and wherein the at least one pressure sensor includes a determining unit configured to determine whether the adsorption holes are clogged by using the measured pressure.

A method of monitoring and controlling a sequential valve gate molding apparatus in an injection molding or other molding process is disclosed. The method includes creating a target strain profile, receiving a deviation limit, receiving a change in strain relating to a first valve gate from a first strain gauge, identifying whether a deviation exists from a first portion of the target strain profile based on the output from the first strain gauge, determining whether any existing deviation exceeds the deviation limit, and adjusting the position of a first valve gate pin in the first valve gate if it does. The method may further include control of subsequent valve gates. Multiple strain gauges may be used to control a single valve gate, and/or each strain gauge may control more than one valve gate.

An injection molding apparatus and method of fabricating a molded part are provided. The apparatus may include a barrel, a nozzle enclosing an end of the barrel and defining an opening in fluid communication with an inside of the barrel, and an extrusion screw positioned at least partially inside the barrel and rotatable relative to the barrel. The extrusion screw may include a screw tip. Relative axial movement between the barrel and the extrusion screw may open or close the opening of the nozzle to permit or prevent, respectively, material flow through the opening of the nozzle. The method may include clamping a mold, opening a nozzle, rotating the extrusion screw to pump a molten material into the mold until the mold is filled, closing the nozzle, and unclamping the mold to release a molded part.

An injection molding machine includes: a first driving device rotating a screw provided inside a heating cylinder; a second driving device moving the screw forward and backward; a metering control section configured to, by controlling the first driving device and the second driving device, to meter resin while melting the resin, and thereafter rotate the screw in reverse to thereby reduce the pressure of the resin; a first sensor unit for detecting the pressure; a second sensor unit for detecting one or more kinds of physical quantities that affect the change of the pressure; and a prediction section predicting decompressing rotation information based on the pressure detected by the first sensor unit and the one or more kinds of physical quantities detected by the second sensor unit. The metering control section controls the first driving device based on the decompressing rotation information predicted by the prediction section.

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.

A method for generating a signal indicative for nozzle maintenance, including feeding modeling material through a feed channel of a printhead to a nozzle of the printhead in a three-dimensional modeling system, determining a parameter indicative of a fluid resistance of modeling material within the nozzle. Determining the parameter includes determining a flowrate of the modeling material within the feed channel, determining a pressure exerted on the modeling material within the feed channel and determining a pressure exerted on the modeling material outside the feed channel, determining a pressure difference between the pressure exerted on the modeling material within the feed channel and the pressure exerted on the modeling material outside the feed channel, and calculating the parameter from the determined flow rate and the determined pressure difference. A method and system for three-dimensionally modeling a three-dimensional object using the method for generating a signal indicative for nozzle maintenance.

An injection molding machine is provided with a nozzle touch mechanism configured to press a nozzle attached to an injection device against a mold, a drive unit configured to move the injection device, a drive compression member connected to the drive unit, an injection compression member connected to the injection device, at least one resilient member interposed preloaded between the drive compression member and the injection compression member, and at least one strain sensor mounted on the drive compression member.

A display device causes a display unit to display a first graph showing the temporal change of a feature value of a physical quantity measured in each molding cycle of an injection molding machine and a second graph showing the temporal change of events that occurred in the injection molding machine, with the time axes of the first graph and the second graph being defined in the same direction on the same scale, based on cycle information indicating the molding cycle in which the feature value was measured and occurrence period information indicating the occurrence time period of the events.

An additive injection system for use in injection molding machines to inject additive materials, such as fluids or powders, downstream of a nozzle of the injection molding machine. The additive injection unit has an additive tank to store or contain additive material and additive injectors that inject an additive material into an injection molding machine. A pump pumps the additive material from the tank through a common manifold connected to the additive injectors to be injected into the injection molding machine. A controller controls operation of the additive injection device and one or more sensors coupled to the additive injection device can provide feedback to the controller.