B29C2945/7601

Method for reproducing injection molded parts of quality and injection molding unit for performing the method
10836088 · 2020-11-17 · ·

A time variation of an internal pressure of the molding cavity of a multi-phase injection molding machine is detected and represented as an internal pressure graph. An internal pressure graph recorded during a production cycle that produced an injection molded part satisfying a predefined quality characteristic is used as a reference graph. If the internal pressure graph of the current production cycle exceeds a predefined threshold value, then a current machine parameter is changed so as to adapt an internal pressure graph of a subsequent production cycle to the reference graph. Each phase of the production cycle is assigned its own machine parameter determined to have a significant impact on the quality of the parts produced. The assigned machine parameters are changed in a predefined order in a plurality of production cycles wherein exactly one assigned machine parameter is changed per production cycle.

Process for molding a thermosetting resin

A method of molding a thermosetting resin, in particular of the epoxy resin type, in which a first mold is filled with the resin while causing the temperature of the resin to vary in application of a first temperature program, without exceeding the Tg of the resin. After the first mold has been filled, the resin is put under pressure while causing the temperature of the resin to vary in application of a second temperature program, without exceeding Tg, and a drop in the pressure exerted by the resin on the mold is detected with the instant at which this pressure presents a break of slope being identified as the instant t1. A second mold is filled with the thermosetting resin in application of the first temperature program. After the second mold has been filled, the resin is put under pressure in application of the second temperature program until an instant t2 close to t1. As from t2, the temperature of the resin is increased to exceed Tg.

CONTROL DEVICE OF INJECTION MOLDING MACHINE, INJECTION MOLDING MACHINE, AND METHOD OF CONTROLLING INJECTION MOLDING MACHINE

A control device includes: an injection control unit that controls, in a pressure holding process of controlling a pressure acting on a molding material from an injection member, an injection drive source based on a set value of the pressure and an actual value of the pressure. The injection control unit performs pressure reduction control to gradually reduce the actual value of the pressure with respect to the set value of the pressure from a middle of a k-th stage (k is an integer of 1 or more and n or less). The control device includes a ratio setting unit that sets a time ratio Tr(k) in the k-th stage and a pressure ratio ?Pr(k) in the k-th stage based on a set value P(k) of the pressure in the k-th stage, a set value T(k) of a holding time in the k-th stage, and information stored in advance.

METHOD FOR REPRODUCING INJECTION MOLDED PARTS OF QUALITY AND INJECTION MOLDING UNIT FOR PERFORMING THE METHOD
20180304513 · 2018-10-25 ·

A time variation of an internal pressure of the molding cavity of a multi-phase injection molding machine is detected and represented as an internal pressure graph. An internal pressure graph recorded during a production cycle that produced an injection molded part satisfying a predefined quality characteristic is used as a reference graph. If the internal pressure graph of the current production cycle exceeds a predefined threshold value, then a current machine parameter is changed so as to adapt an internal pressure graph of a subsequent production cycle to the reference graph. Each phase of the production cycle is assigned its own machine parameter determined to have a significant impact on the quality of the parts produced. The assigned machine parameters are changed in a predefined order in a plurality of production cycles wherein exactly one assigned machine parameter is changed per production cycle.

Resin molded article manufacturing device, and manufacturing device control method

A manufacturing apparatus for manufacturing a resin molded article includes: an injection molding part configured to inject resin into an injection mold and injection-mold the resin molded article; a control unit configured to control the injection by the injection molding part; a calculation unit configured to calculate a pressure reduction curve for reducing a pressure generated by the injection; and an input unit via which a user inputs a condition of the pressure reduction curve, in which the control unit is configured to control the injection based on the pressure reduction curve.

Injection molding machines and methods for accounting for changes in material properties during injection molding runs

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.

METHOD AND APPARATUS FOR PROCESS MONITORING DURING PRODUCTION OF A FINISHED PART FROM A HOT-CROSSLINKING MATERIAL IN A PRIMARY SHAPING PROCESS

The invention relates to a method for process monitoring during production of a finished part (112) in a primary shaping process. The method comprises the following steps: a) providing at least one mould (114) designed for the primary shaping process, wherein the mould (114) has at least one cavity (116) for receiving at least one starting material for the hot-crosslinking material, and wherein an apparatus for determining a mould internal pressure is also integrated into the mould (114); b) heating the mould (114); c) introducing the at least one starting material for the hot-crosslinking material into the cavity (116) under pressure such that the finished part (112) is produced; d) detecting a progression of the mould internal pressure occurring in step c); e) differentiating, at least once or at least twice, the progression of the mould internal pressure in order to determine at least one derivative selected from the group consisting of: the first-order derivative and the second-order derivative; and f) characterising a progression of a chemical crosslinking reaction by means of at least one derivative selected from the group consisting of: the first-order derivative and the second-order derivative.

Control device for injection molding machine and control method for injection molding machine

The present invention offers a technique for providing assistance in setting at least one of the temperature of a nozzle and the temperature of a cylinder. A control device for an injection molding machine includes a monitoring part configured to monitor, during a filling step of filling the inside of a mold device with a molding material, a change in the filling pressure acting on the molding material.