A low pressure injection mold includes a failsafe pressure mechanism that prevents the low pressure injection mold from being subjected to excessive injection pressures or excessive clamping tonnage that could damage the low pressure injection mold.

A process of forming molded articles using an injection molding apparatus is provided. The process includes providing a thermoplastic material to the injection molding apparatus. The thermoplastic material is heated such that the thermoplastic material is in a molten state. The molten thermoplastic material is injected into at least one mold cavity of the injection molding apparatus using an injection element. Melt pressure of the thermoplastic material filling the at least one mold cavity is monitored using a sensor. The sensor provides a signal indicative of melt pressure to a controller. The controller controls introduction of a non-reactive additive to the thermoplastic material thereby changing a viscosity of the molten thermoplastic material based on the signal. A molded article is formed by reducing a mold temperature of the thermoplastic material within the at least one mold cavity.

A process of forming molded articles using an injection molding apparatus is provided. The process includes providing a thermoplastic material to the injection molding apparatus. The thermoplastic material is heated such that the thermoplastic material is in a molten state. The molten thermoplastic material is injected into at least one mold cavity of the injection molding apparatus using an injection element. A melt pressure of the thermoplastic material filling the at least one mold cavity is monitored using a sensor. The sensor provides a signal indicative of melt pressure in the cavity to a controller. The controller controls the injection element thereby changing melt pressure of the thermoplastic material filling the at least one mold cavity based on the signal to reach a target cavity pressure. A molded article is formed by reducing a mold temperature of the thermoplastic material within the at least one mold cavity.

An injection assembly including a cover part which covers an upper surface of a controller and in which a plurality of injection holes are formed to correspond to positions of a plurality of heating elements and a nozzle unit including a plurality of nozzles to simultaneously inject an injection material into the plurality of injection holes, wherein a pressure sensor is disposed in each of the plurality of nozzles to measure an internal pressure of the nozzle and to control an injection speed based on the measured internal pressure.

Disclosed herein is a novel shut-off nozzle for use with an injection molding system for creating and injecting foaming polymers to form products and other components. The shut-off nozzle is designed to increase cell nucleation during the foaming process, increase the pressure drop rate as the polymer is injected into a mold, and stop drooling of the foamed polymer at the end of an injection cycle. The shut-off nozzle includes an angled shut-off needle, which significantly reduces the amount of waste in each injection cycle and a water-cooling circuit to rapidly cool and solidify the molten polymer remaining in the shut-off nozzle at the end of each injection cycle.

Disclosed herein is a novel shut-off nozzle for use with an injection molding system for creating and injecting foaming polymers to form products and other components. The shut-off nozzle is designed to increase cell nucleation during the foaming process, increase the pressure drop rate as the polymer is injected into a mold, and stop drooling of the foamed polymer at the end of an injection cycle. The shut-off nozzle includes an angled shut-off needle, which significantly reduces the amount of waste in each injection cycle and a water-cooling circuit to rapidly cool and solidify the molten polymer remaining in the shut-off nozzle at the end of each injection cycle.

Systems and approaches for controlling a molding machine having a mold forming a mold cavity, a nozzle, and a screw that moves from a first position to a second position toward the nozzle and being controlled according to a mold cycle. Injecting a molten polymer into the mold cavity and obtaining a first measurement of a variable during the injection cycle using a first sensor positioned at or near the screw. A second sensor positioned at or near the nozzle is used to obtain a second measurement of the variable during the injection cycle. A measured compressibility ratio value is determined in the form of a difference between the measured variable obtained by the first sensor and the measured variable obtained by the second sensor. The measured compressibility ratio value is compared with a reference compressibility ratio value and at least one control parameter is adjusted based on a difference between the reference compressibility ratio value and the measured compressibility ratio value.

Disclosed herein are novel methods for forming a polymer part including providing an injection molding system with a shut-off nozzle, where the shut-off nozzle includes a main body, a nozzle tip body, a flow path through the main body and the nozzle tip body, a nozzle tip, and a shut-off mechanism. The nozzle tip includes an internal passage and a cooling mechanism. The shut-off mechanism includes a passageway intersecting the flow path at an angle and a pin positioned in the passageway. The method further includes the steps of initiating an injection molding cycle by injecting molten polymer through the shut-off nozzle into a cavity of a mold, actuating the shut-off mechanism to move the pin in the passageway into the intersection of the passageway and flow path, and initiating the cooling mechanism to solidify molten polymer in the nozzle tip to form a solid slug.

Disclosed herein are novel methods for forming a polymer part including providing an injection molding system with a shut-off nozzle, where the shut-off nozzle includes a main body, a nozzle tip body, a flow path through the main body and the nozzle tip body, a nozzle tip, and a shut-off mechanism. The nozzle tip includes an internal passage and a cooling mechanism. The shut-off mechanism includes a passageway intersecting the flow path at an angle and a pin positioned in the passageway. The method further includes the steps of initiating an injection molding cycle by injecting molten polymer through the shut-off nozzle into a cavity of a mold, actuating the shut-off mechanism to move the pin in the passageway into the intersection of the passageway and flow path, and initiating the cooling mechanism to solidify molten polymer in the nozzle tip to form a solid slug.

A material discharge device includes: a drive motor; a screw having a groove formation surface and configured to rotate; a barrel having a facing surface and formed with a communication hole through which a plasticized material flows; a heating unit configured to heat the material; a nozzle from which the material is injected to an outside; and a plurality of measurement units configured to measure a pressure or a temperature of the material. The measurement units are disposed at an outer periphery of a nozzle channel wall, and a thickness of the nozzle channel wall satisfies the following (1) or (2): (1) when the nozzle channel wall is made of a material containing iron as a main component, the thickness of the nozzle channel wall is 0.2 mm or more and 2.5 mm or less; and (2) when the nozzle channel wall is made of a material containing aluminum as a main component, the thickness of the nozzle channel wall is 0.2 mm or more and 4 mm or less.