A pressure controller for an injection molding machine capable of reducing variations of pressure in a mold in molding cycles and providing molded articles of stable quality is provided. The pressure controller includes an in-mold pressure estimation unit for estimating a pressure in the mold based on an injection pressure detected with an injection pressure detection unit, and an amount of movement of a screw detected with a screw movement amount detection unit, and an in-mold pressure control unit for controlling such that the estimated in-mold pressure becomes a set in-mold pressure after the pressure control is performed in a dwell step with an injection pressure control unit.

A method of determining melt flow front travel in a molding apparatus includes setting a sensor threshold, receiving a sensor amount as an output from a sensor monitoring a nozzle of the molding apparatus, and determining that the sensor amount exceeds the sensor threshold. The method further includes receiving a screw location, calculating a travel distance of the screw from the screw location, and calculating melt flow front travel based on the travel distance of the screw. The method further includes receiving, via an interface, an operator generated value for the desired melt flow front travel to be reached, and sending, via an interface, an analog or digital output after the operator generated value has been reached. A method of detecting a leaking condition of a check valve is also included.

Non-time dependent measured variables are used to effectively determine an optimal hold profile for an expanding crosslinking polymer part in a mold cavity. A system and/or approach may first inject molten expanding crosslinking polymer into a mold cavity, then measure at least one non-time dependent variable during an injection molding cycle. Next, the system and/or method commences a hold profile for the part, and upon completing the hold profile, the part is ejected from the mold cavity.

An injection molding machine includes an injection member that pushes a molding material and an injection drive source that moves the injection member. A control device of the injection molding machine includes an injection control unit that controls a stop process for stopping a movement of the injection member and a holding pressure process for controlling a pressure acting on the molding material from the injection member, a pressure monitoring unit that monitors an actual value of the pressure in the stop process, and a timing setting unit that sets a timing when the stop process is to be switched to the holding pressure process on the basis of the actual value of the pressure in the stop process and a value offset from a set value of the pressure at a time of start of the holding pressure process to a high pressure side by a predetermined amount.

A particle simulation program is disclosed. A computer forms a particle generation surface in a vicinity of an inflow port. The computer forms a particle disappearance surface representing a boundary to eliminate particles depending on the particle generation surface. The computer performs a particle simulation, in which the particles of fluid filled in a vessel are flowed out from the inflow port. The computer periodically generates the particles from the particle generation surface. The computer eliminates a particle crossing out of the particle disappearance surface.

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.

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 uses lower temperatures, when compared to molding according to the original mold cycle.

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.

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.

An injection molding machine includes: a clamping device having a fixed mold and a movable mold, configuring a mold, and a clamping force sensor to detect a clamping force of the movable mold to the fixed mold; an injection device having an injection nozzle and a screw to fill the mold with a molten resin via the injection nozzle; and a control device, wherein the control device monitors a variation of the clamping force from the clamping force sensor, causes a slow speed forward movement time at a timing of VP switching to be increased if the variation exceeds a predetermined upper limit, and causes the slow speed forward movement time at the timing of VP switching to be reduced if the variation falls below a predetermined lower limit.