A method for controlling an injection cycle of an injection molding machine incudes advancing an injection screw axially forward toward an injection nozzle from a shot-size position to an injection position to inject melt from a shot chamber into a hot runner of a mold and from the hot runner to fill cavities of the mold. Then the injection screw is retracted away from the nozzle, from the injection position to a decompression position axially rearward of the shot-size position, to relieve melt pressure in the hot runner. Then the screw is advanced toward the nozzle from the decompression position to an intermediate position axially intermediate the injection position and the shot-size position. The method then includes rotating the screw to re-fill the shot chamber with melt and urge the screw to retract from the intermediate position to the shot-size position.

A method for determining positions of a real moulding material front during a process to be carried out with a moulding machine, wherein a simulation progression (SV) of a variable characteristic of the process is calculated, positions of a simulated moulding material front are determined from the simulation, the real process is carried out, and at least one measurement progression (MV) of the at least one characteristic variable is measured directly or indirectly, a transformation is chosen, which has at least one parameter (ΔV, kp, V.sub.unknown), the transformation is applied to the at least one simulation progression (SV), with the result that a transformed simulation progression (tSV) is formed, and a parameter value is determined for the parameter (ΔV, kp, V.sub.unknown) such that a deviation between the measurement progression (MV) and the transformed simulation progression (tSV) is minimized according to a predetermined error measure or according to an operator input.

A method for determining positions of a real moulding material front during a process to be carried out with a moulding machine, wherein a simulation progression (SV) of a variable characteristic of the process is calculated, positions of a simulated moulding material front are determined from the simulation, the real process is carried out, and at least one measurement progression (MV) of the at least one characteristic variable is measured directly or indirectly, a transformation is chosen, which has at least one parameter (ΔV, kp, V.sub.unknown), the transformation is applied to the at least one simulation progression (SV), with the result that a transformed simulation progression (tSV) is formed, and a parameter value is determined for the parameter (ΔV, kp, V.sub.unknown) such that a deviation between the measurement progression (MV) and the transformed simulation progression (tSV) is minimized according to a predetermined error measure or according to an operator input.

A method for decorative molding capable of reducing a preparation time at the time of replacing a mold and expecting improvement in positioning accuracy of a decorative pattern in a molded article includes supplying a film on which a decorative pattern is formed between a first mold and a second mold in a mold open state of a mold, imaging a mold-side alignment mark recorded in the mold and a film-side alignment mark recorded in the film by a camera, positioning the film with respect to the mold by moving the film so that the film-side alignment mark comes close to the mold-side alignment mark, injecting resin into the mold in a mold closed state in which the film is sandwiched between the first mold and the second mold and cooling the resin to form a molded article and opening the mold and taking out the molded article in which the decorative pattern of the film is transferred to the surface.

A method for decorative molding capable of reducing a preparation time at the time of replacing a mold and expecting improvement in positioning accuracy of a decorative pattern in a molded article includes supplying a film on which a decorative pattern is formed between a first mold and a second mold in a mold open state of a mold, imaging a mold-side alignment mark recorded in the mold and a film-side alignment mark recorded in the film by a camera, positioning the film with respect to the mold by moving the film so that the film-side alignment mark comes close to the mold-side alignment mark, injecting resin into the mold in a mold closed state in which the film is sandwiched between the first mold and the second mold and cooling the resin to form a molded article and opening the mold and taking out the molded article in which the decorative pattern of the film is transferred to the surface.

A control device for an injection molding machine is equipped with a pressure acquisition unit configured to acquire a resin pressure, a pressure reduction control unit configured to, after the screw has reached a predetermined metering position, reduce the resin pressure to a target pressure by performing at least one of reverse rotation and sucking back of the screw, and a standby pressure control unit configured to, after the resin pressure has reached the target pressure, keep the resin pressure within a predetermined range by causing the screw to be rotated in a state in which a position of the screw in an axial direction of the cylinder is maintained.

A control device for an injection molding machine is equipped with a pressure acquisition unit configured to acquire a resin pressure, a pressure reduction control unit configured to, after the screw has reached a predetermined metering position, reduce the resin pressure to a target pressure by performing at least one of reverse rotation and sucking back of the screw, and a standby pressure control unit configured to, after the resin pressure has reached the target pressure, keep the resin pressure within a predetermined range by causing the screw to be rotated in a state in which a position of the screw in an axial direction of the cylinder is maintained.

A method of manufacturing an in-mold decorative molded article includes supplying an in-mold transfer foil to a metal mold, injecting and cooling a molding resin and taking out an molded article formed of the molding resin cooled and cured in the metal mold in which a clear layer and a transfer layer having a decorative figure in the in-mold transfer foil are integrated on the surface by opening the mold, molding the molded article integrally with a cutting portion not necessary for a target product inside the metal mold by the molding resin at an outer periphery of the product and arranging a boundary of a printing region of the clear layer in the in-mold transfer foil in the cutting portion so as to be larger than the outer periphery of the product.

A method of manufacturing an in-mold decorative molded article includes supplying an in-mold transfer foil to a metal mold, injecting and cooling a molding resin and taking out an molded article formed of the molding resin cooled and cured in the metal mold in which a clear layer and a transfer layer having a decorative figure in the in-mold transfer foil are integrated on the surface by opening the mold, molding the molded article integrally with a cutting portion not necessary for a target product inside the metal mold by the molding resin at an outer periphery of the product and arranging a boundary of a printing region of the clear layer in the in-mold transfer foil in the cutting portion so as to be larger than the outer periphery of the product.

A preheat assisted injection/compression molding system for producing thin wall, high fiber content, high flex modulus thermoplastic composites at high temperature includes a press, an injection mold operably coupled to the press and including a first mold portion having a first inner mold surface, and a second mold portion with a second inner mold surface, and a resin injection system configured to inject a molten, free flowing resin into the injection mold. A mold surface pre-heating system includes a heating element configured to selectively heat at least one of the first and second inner mold surfaces to a predetermined temperature at a predetermined depth before the resin is injected into the mold. A cooling system is configured to selectively cool at least one of the first and second inner mold surfaces to rapidly cool a molded part formed by compressing the resin with the press.