Injection machine for molding thermoplastic products has separate plasticizing and injection units brought together to charge the injection unit with plastic and handling system for moving separated injection unit to tool

摘要

The injection machine has separate plasticizing(1) and injection(2) units which can be pressed against each other for charging the latter with plasticized thermoplastic and then separated again. The separate injection unit can then be moved by a handling system(3) for a subsequent injection cycle. The injection unit(2) has an inlet(10) at the opposite side to the injection nozzle(5) and the nozzle design may also permit charging of the injection unit through the nozzle instead of an inlet. One type of injection unit has a cylinder with piston for injection of plastic in the cylinder. The piston may have a bore with a non-return valve through which plastic is fed into the cylinder. Energy supply lines(4) are connected to the injection unit(2) as are hydraulic or electric drives for injecting the plastic. A second type of injection unit may have a propellant or explosive charge for plastic injection or can be connected to such systems. A further type of injection unit may be connected to a hydropneumatic and/or mechanical pressure accumulator or one of these may be integrated in the injection unit. The injection unit can be heated and/or cooled. Stored energy is sufficient for injecting the thermoplastic and applying holding pressure as the molding cools. An independent claim is included for a process for operating the injection machine in which the injection unit(2) is charged with energy while the injection unit is connected to the plasticizing unit for supplying plasticized thermoplastic.