An injection molding machine usually consists of injection system, mould closing system, hydraulic transmission system, electric control system, lubrication system, heating and cooling system, safety monitoring system and so on. Here we will see how each system is structured and what kind of role it plays.
Injection system
Role of injection system: the injection system is one of the most important components of the plastic injection machine, generally there are plunger type, screw type, screw pre-moulding plunger injection in 3 major forms. At present, the most widely used is the screw type. Its role is, in a cycle of plastic injection machine, can be in the specified time will be a certain amount of plastic heating and plasticising, under a certain pressure and speed, through the screw will be injected into the mould cavity of molten plastic. After injection, the melt injected into the mould cavity is kept in shape.
The composition of the injection system: The injection system consists of a moulding device and a power transmission device.
A screw moulding plastic machine consists of a feeder, cylinder, screw and nozzle. The power-transmitting device includes the injection cylinder, the cylinder for moving the injection seat and the screw drive (melt motor).
Mould closing system
The role of the mould closing system: The role of the mould closing system is to ensure that the mould is closed, opened and products are ejected. At the same time, after the mould is closed, sufficient clamping force is applied to the mould to prevent the mould cavity pressure generated by the molten plastic from entering the mould cavity, preventing the mould from opening and resulting in the undesirable state of the products.
Mould closing system composition: The mould closing system consists of mould closing device, mould adjusting machine, ejector mechanism, front and rear fixed templates, mobile templates, mould closing cylinder and safety protection mechanism.
Hydraulic system
The role of hydraulic transmission system is to achieve the injection moulding machine according to the process required by the various actions to supply power, and sufficient injection moulding machine required pressure, speed, temperature and other requirements. It is important by their respective types of hydraulic components and hydraulic auxiliary support components, including oil pumps and motors are the power source of the injection molding equipment. Various valves control the oil pressure and flow, so that sufficient injection moulding process requirements.
Heating/cooling system
The heating system is used to heat the cylinder and the nozzle. The barrel of the plastic injection moulding machine generally adopts the electric heating ring as the heating device, which is installed on the outside of the barrel and detected by thermocouple segments. The heat is conducted through the barrel wall to provide a heat source for material plasticisation; the cooling system is important for cooling the oil temperature, which is too high and will cause many kinds of faults, so the oil temperature must be controlled. The other cooling position is near the material mouth of the material tube to prevent the raw material from melting at the mouth, which will cause the raw material to be unable to be discharged normally.
Lubrication system
The lubrication system is a circuit for providing lubrication conditions to the relatively moving parts of the injection moulding machine, such as the moving template, mould adjusting device, connecting rod hinge, etc., so as to reduce the energy consumption and improve the service life of the parts, and the lubrication can be manual lubrication at regular intervals or automatic electric lubrication;
Safety protection and control system
The safety device of the injection moulding machine is important for the protection of human and machine safety. It is composed of safety door, hydraulic valve, limit switch, photoelectric detection element and so on, to realise the interlock protection of electric machine and hydraulic pressure. The monitoring system is important to monitor the oil temperature, material temperature, system overload, and process and equipment failure of the injection moulding machine, and to display or alarm the abnormal situation.
FAQ’s
The seven systems include the clamping, injection, hydraulic, electrical, control, heating/cooling, and safety systems—each with a specific role in the moulding process.
It directly handles melting and injecting plastic into the mould, controlling material flow and shot precision.
It securely holds the mould closed during injection and opens it for part ejection, ensuring cycle stability.
