The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.

The injection moulding of articles formed by plastic materials having different characteristics, for example of different colours, is carried out in a single injection cycle in which the first and the second plastic materials are injected into a first and into a second zone of a mould cavity by first and second injectors controlled according to specific modes so as to define a shape and/or a position of a weld line.

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.

An Injection molding apparatus injection molding apparatus (10a) comprising: one or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) that deliver injection fluid (18) to a first cavity (300a) of a mold system (302, 303) and to one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) that deliver injection fluid to a second cavity (300b) of the mold system (302, 303), the mold system being clamped together under a selected force, the apparatus including a first upstream valve (118) that enables and disables flow of the injection fluid to the first gates (34, 34a, 34b) and a second upstream valve (108) that enables and disables flow of the injection fluid to the one or more second gates (32, 32a, 32b), the apparatus including a control system (20) adapted to open or enable flow of the injection fluid (18) to the one or more first gates (34, 34a, 34b) at a first selected time and to further instruct the second upstream valve (108) to open or enable flow of the injection fluid (18) to the one or more second gates (32, 32a, 32b) at a second selected time that is delayed relative to the first selected time during the course of an injection cycle.

A method of forming a urinary catheter is disclosed that includes injecting a polymer melt through a primary melt channel and into an elongated recess around an outer surface of a core; and controlling a first pressure of the polymer melt in a first secondary melt channel separately and individually from a second pressure of the polymer melt in a second secondary melt channel and reducing stress of the polymer melt along the elongated recess. Opening the mould and removing the core provides a moulded intermittent urinary catheter having an open distal end and a closed proximal tip.

An Injection molding apparatus injection molding apparatus (10a) comprising: one or more first downstream channels (166, 166a, 166b) and associated first gates (34, 34a, 34b) that deliver injection fluid (18) to a first cavity (300a) of a mold system (302, 303) and to one or more second downstream channels (168, 168a, 168b) and associated second gates (32, 32a, 32b) that deliver injection fluid to a second cavity (300b) of the mold system (302, 303), the mold system being clamped together under a selected force, the apparatus including a first upstream valve (118) that enables and disables flow of the injection fluid to the first gates (34, 34a, 34b) and a second upstream valve (108) that enables and disables flow of the injection fluid to the one or more second gates (32, 32a, 32b),
the apparatus including a control system (20) adapted to open or enable flow of the injection fluid (18) to the one or more first gates (34, 34a, 34b) at a first selected time and to further instruct the second upstream valve (108) to open or enable flow of the injection fluid (18) to the one or more second gates (32, 32a, 32b) at a second selected time that is delayed relative to the first selected time during the course of an injection cycle.

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.

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.

An injector includes a nozzle provided with a valve seat, a valve body which is seated on or separated from the valve seat, and a displacement means for displacing the valve body. A resin flow passage through which molten resin flows is formed inside the nozzle. The resin flow passage includes a cross-sectional area varying portion having a cross-sectional area, in a direction orthogonal to a flow direction, which varies with increasing distance toward or away from the valve body. The displacement means is capable of stopping the valve body in any position in the cross-sectional area varying portion.

A method of performing an injection cycle having a duration comprising: beginning the injection cycle with the valve pins associated with two or more nozzles in a gate closed position, selecting a first one of the two or more nozzles and controllably driving its associated valve pin from the gate closed position to a selected first axial upstream position, upon downstream flow of the injection fluid through a cavity the preselected distance, controllably driving the valve pin associated with the other of the two or more nozzles to a selected second axial position upstream, holding or controllably driving the valve pin associated with the first one of the two or more nozzles in or to one or more reduced flow axial upstream positions that are partially closed.