A method and system for adjusting melt pressure in an injection molding material that allows calculating a melt pressure of a molten plastic material to be injected and based on the calculated melt pressure and a desired melt pressure adjusting operation of an injection molding machine. This control of an injection molding cycle using the method and system of plastic melt pressure determination allows production of parts of increased quality and consistency.

An injection molding system comprising: a first selected valve, one or more downstream valves, delivering a fluid to a mold cavity, at least one fluid property sensor that detects a flow front of fluid material flowing downstream through the mold cavity at a trigger location within the cavity disposed between the first gate and at least one selected downstream gate, a controller instructing an actuator associated with the downstream gates to open the gates at a predetermined open gate target time on a first injection cycle, each valve associated with a position sensor that detects opening of a gate at an actual open gate time to the controller, the controller automatically adjusting time of instruction to open the gates on a subsequent injection cycle by an adjustment time equal to any delay in time between the predetermined open gate target time and the actual open gate time.

Injection molding system comprising at least one first actuator-system (D1, D2, D3), the first actuator system comprising: at least one piston drive having at least two pressure line connectors (CP2, CP3) to drive a piston to open or close a molding nozzle, pressure lines (L1, L2) connectable to a changeover valve (V) having a pressure line connector (P) and tank line connector (T) and at least two changeover pressure line connectors, wherein the first changeover valve pressure line connector (CV1) is connectable to a first pressure line (L1) and the second changeover valve pressure line connector (CV2) is connectable to a second pressure line (L2), wherein the second pressure line (L2) is connected to the second pressure line connector (CP2) of the piston drive, an electronically adjustable flow control valve having a first pressure line connector and a second pressure line connector, wherein the first pressure line connector of the adjustable flow control valve being connected to the first pressure line (L1) to allow a connection to the first pressure line connector (CV1) of the changeover valve (V), and the second pressure line connector is connected to a third pressure line (L3) which establishes a connection to the second pressure line connector (CP3) of the piston drive, at least one electronic flow sensor for (P1, P2, P3) sensing flow rate in the first, second and/or third pressure lines (L1, L2, L3), a controller connected to the adjustable flow control valve and to the at least one sensor, configured to electronically adjust the flow control valve, depending on information of the at least one sensor, controlling thereby the timing and the speed of the movement of the piston and the molding nozzle.

The invention relates to a device (1) for supplying at least one molding device (2) with a polymerizable mixture of at least two reactants. According to the invention, said supply device comprises: a buffer tank (10) suitable for receiving said polymerizable mixture via an inlet (101) of said buffer tank, a supply circuit (11), looped with said buffer tank, to convey the polymerizable mixture to an inlet (110) of said at least one molding device and including, beyond said inlet of the molding device, a return pipe (115) connected to the inlet of the buffer tank for sending a portion of the polymerizable mixture from said return pipe, and a filling pipe (42) of said buffer tank, connected to said inlet of said buffer tank, separate from the return pipe, wherein said buffer tank is also suitable for receiving said polymerizable mixture or at least one of said reactants from said filling pipe.

An injection molding machine includes a cylinder that accommodates a molten resin, a discharging nozzle, a piston that discharges the molten resin from the discharging nozzle, and one or more processors configured to execute the following functions. The functions include calculating a target pressure at which a flow rate of the molten resin discharged from the discharging nozzle becomes an indicated flow rate, controlling a pressure of the molten resin in the cylinder such that the pressure becomes the target pressure, acquiring a temperature of the molten resin in the cylinder, and acquiring a pseudo-plastic viscosity corresponding to the temperature of the molten resin. The target pressure is calculated based on the indicated flow rate, the temperature of the molten resin, the pseudo-plastic viscosity, and the size of the discharging nozzle.

The invention relates to a hydraulic device for supplying a plurality of work units (3a, 3b), in particular on a plastics injection moulding machine, said device comprising at least one controller (7), at least one valve regulator and/or one valve controller and a central drive (1). A regulating valve (13a, 13b) with a regulating-valve geometry is provided on at least one of the work units (3a, 3b). Pressure sensors (8) detect at least one pressure both upstream and downstream of the regulating valve (13a, 13b), the load pressure (10a, 10b) of at least one of the work units (3a, 3b), and the system pressure (9). Since the valve regulator and/or the valve controller has knowledge about the regulating-valve geometry of the at least one regulating valve (13a, 13b) and is designed to derive, from a relationship between the regulating-valve geometry and at least one pressure difference resulting from the pressures detected upstream and downstream of the regulating valve (13a, 13b), at least one volume flow rate actual value per regulating valve (13a, 13b), and the controller (7) is designed to derive, from the volume flow rate setpoint values of the at least one work unit (3a, 3b) and/or the volume flow rate actual values of the at least one regulating valve (13a, 13b), at least one setpoint value feedforward control for the central drive (1) in such a way that the system pressure (9) corresponds at least to the relevant highest load pressure (10a, 10b) of the work units (3a, 3b), the hydraulic device is improved in terms of functionality, energy, efficiency and economy.

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.

An injection molding machine uses a controller to effectively control its operation. The controller may determine and/or receive information regarding the machine's maximum load capacity, and may also determine a current operational load value of the machine. The controller also may determine a number of set points used to operate the machine. The controller may cause the machine to operate at these set points, thereby resulting in the machine operating at or below the maximum load value by adjusting any number of machine parameters associated with the injection molding machine.

For each of different resins R, a zero shear viscosity ?o of each resin R is obtained by using a conversion function expression whose parameters are a melt flow rate (MFR) and a set temperature of a heating cylinder and is registered. Also, a purge resin required amount Wu corresponding to a viscosity difference ?d between the zero shear viscosity ?of of a former resin Rf and the zero shear viscosity ?os of a succeeding resin Rs is registered. When resin switching is performed, the zero shear viscosity ?of of the former resin Rf and the zero shear viscosity ?os of the succeeding resin Rs are obtained by inputting the MFR of the former resin Rf and the MFR of the succeeding resin Rs to a molding machine controller, the viscosity difference ?d between the zero shear viscosity ?of of the former resin Rf and the zero shear viscosity ?os of the succeeding resin Rs is obtained, an amount of a purge resin required for resin switching is obtained as a purge resin required amount Wu, and at least the obtained purge resin required amount Wu is displayed.

The present disclosure provides a molding system for preparing a fiber-reinforced thermoplastic composite article. The molding system includes: a molding machine; a mold disposed on the molding machine and having a mold cavity for being filled with a composite molding material including a polymeric resin and a plurality of fibers; a processing module configured to generate an anisotropic stress distribution of the composite molding material in the mold cavity based on a molding condition for the molding machine; and a controller coupled to the processing module and configured to control the molding machine with the molding condition to perform an actual molding process for preparing the fiber-reinforced thermoplastic composite article. The anisotropic stress distribution of the composite molding resin is generated based in part on consideration of an integral effect of an elongational viscosity and a shear viscosity of the composite molding material.