摘要:
Controlling viscosity of molten polymers, such as polycarbonate, prior to a molding operation such as injection molding, extrusion, thermoforming or blow molding, involves a reduction of viscosity in the plastic melt at constant temperature, by the action of a vigorous mechanical extensional shear vibration, with minimum or no external pressure, at a constant amplitude and frequency, causing the melt to become highly elastic and simultaneously fatigued for a certain time at that temperature, maintaining this high elastic state until the macromolecules have partially or totally disentangled, in a controllable manner, at which stage the melt is ready for a molding operation such as a simple quenching operation or an extrusion process followed by quenching to produce pellets or compounds with a better mix or a lower viscosity when remelted, or an injection molding operation where the melt viscosity has been greatly reduced allowing a better processability of the injected part.
摘要:
There is disclosed an injection molding machine comprising a movable die plate (18) for mounting said movable die (1b). A housing with a toggle mechanism and a pressure sensor (7) placed between said movable die plate (18) and said housing. A servo motor (31) is provided for driving the toggle mechanism (T) and also for injection control. In a resin filling process, a reactive force of said movable die (1b) due to filling resin in the die cavity (2) is detected by said pressure sensor (7). Resin injection into the die cavity (2) is feedback-controlled based on an output data of said resin filled from said pressure sensor (7). In a die compression process and a following pressure-holding process, the feedback control on the die clamping force by said servo motor (31) and position control of said movable die (1b) are carried out based on the data from said pressure sensor.
摘要:
A die compression injection molding method for an injection molding machine (A) for a precision molding thereof, comprises;
(a) injecting weighed resin (3a) into a die cavity (2) of dies (1) in the course of moving in a die closing direction of a movable die (1b); (b) carrying out gate cutting when a specified amount of resin (3) is filled, continuously moving the movable die (1b) in the die closing direction to a specified position, (c) keeping the dies clamping with holding pressure at said specified position during the holding pressure process and the cooling process, (d) after said cooling process, removing the molding from the open dies (1).
摘要:
An apparatus has servo motors(11), (12), (31), (40), (45), and (51) used for driving sources in processes of weighing blended resin(3b), of injecting weighed resin(3a) into a die cavity(2), of opening and closing dies, of gate cutting after filling weighed resin(3a) into the die cavity(2), of ejecting the molding(26) after forming, and of removing the molding(26). According to this configuration, because all the motions of injection operation are controlled by servo motors (11), (12), (31), (40), (45), and (51), the timing, injection speed, pressurizing speed, pressurizing pressure, and all others can be freely controlled, and not only the transferability of fine protrusions and recessions formed on the inner surface (5) of the die cavity (2) can be remarkably improved, but also the cycles can be increased because complex motions can be carried out by servo motors (11), (12), (31), (40), (45), and (51). In particular, because servo motors (45), (51) are used for driving sources of ejection of molding(26) after forming and removal of molding (26), there is no variation in repetitive response accuracy in motion, product removal timing by the product removing equipment(S) can be reduced to 0.01 second or less, and ultimately higher cycle is able to be achieved.