Plastic molding is a cyclic process, with each cycle including: dosing – molten plastics – Injection pressure – Filling the cooling – Kai-mode pickup. Remove the plastic parts and then re-closed mode, the next cycle.
1.2 The structure of the injection molding machine
Plastics injection molding machine according to two ways of piston and screw injection molding machine injection molding machine; according to machine transmission mode can be divided into hydraulic, mechanical and hydraulic – mechanical (link) type; divided automatically by operation , semi-automatic, manual injection molding machine.
(1) horizontal injection molding machine: This is the most common type. Its part and injection mold parts at the same level center line, and the mold is opened along the horizontal direction. Its characteristics are: body short, easy operation and maintenance; machine center of gravity is low, install a more stable; products after the top of the automatic use of gravity down, easy to implement fully automatic operation. At present, injection molding machines on the market to use more of this type.
(2) vertical injection molding machine: its part and injection mold parts in the same vertical center line, and the mold is opened along the vertical direction. Therefore, its small footprint, easy to place inserts, more convenient loading and unloading the mold, the material from the hopper into the plastics can be more evenly. But the product is not easy automatic ejection after the fall, must be removed by hand, not easy to achieve automatic operation. Vertical injection molding machine should be used for small injection molding machine, generally less than 60 grams in the injection molding machine with more large and medium-sized machines should not be used.
(3) angle injection molding machine: the injection direction and the interface in the same mold surface, it is particularly suitable for machining center parts of the plane not allowed to leave the gate traces of products. It covers an area smaller than the horizontal injection molding machine, but it inserts into the mold easily tilted down. This type of injection molding machine should be used for small machines.
(4) multi-mode rotary injection molding machine: it is a special multi-station plastic molding machine operation, which is characterized by the rotary clamping device structure, mold around the shaft rotation. This type of injection molding machine injection device into full play the plasticizing ability to shorten the production cycle and improve the productive capacity of the machine, which is particularly suitable for cooling and sizing a long time or place inserts for supporting the time and need more plastic in large quantities products production, but a large clamping systems, complex clamping device clamping force tend to be smaller, so that the plastic molding machines in the production of soles and other products used more often.