Briefly describe injection molding machine

Posted by sere on November 19th, 2020

First.Factors Affecting Mold Polishing Quality

Because manual polishing is mainly done manually, polishing technology is still the main reason that affects polishing quality. In addition, it is also related to the pet preform mold material, the surface condition before polishing, and the heat treatment process. High-quality steel is a prerequisite for good polishing quality. If the surface hardness of the steel is uneven or the characteristics are different, polishing will often be difficult. Various inclusions and pores in steel are not conducive to polishing.

Second.Preventive measures for injection molding machine

1. Calculate the clamping force correctly, do not increase the better.

2. Do not keep the high-voltage clamping state when stopping.

3. In the event of a power outage in the clamping mode, it must be dealt with in a timely manner, and the cross-head nut must be loosened before the time has passed.

4. Regularly check the mechanical oil. Do not block the solenoid valve with foreign iron filings.

5. Check the lubrication of the clamping system.

Third.The basic process of injection molding machine

(1) During the mold clamping process, the pressure oil in the mold clamping cylinder pushes the clamping mechanism to move, and the movable template moves to close the mold. Among them, theinjection mold is first closed at low pressure and high speed; when the moving template is close to the fixed template, it is switched to low speed and low pressure (that is, the mold protection conditions); when it is confirmed that no foreign matter exists in the mold, it is switched to high pressure (mold clamping). Force), and lock the mold.

(2) After the mold is locked with the clamping force during the injection process of the injection device, the injection device enters the working condition to make the nozzle and the mold fit. After the injection solenoid valve is energized, the injection cylinder is filled with pressure oil, the screw connected to the piston rod of the cylinder is pushed, and the melt in the barrel is injected into the locked mold cavity according to the graded pressure and speed.

(3) During the process of filling the cavity during the filling of the cavity until the filling is completed, the screw is required to maintain a certain pressure on the molten material to prevent the melt from flowing back in the mold; at the same time, the holding pressure is applied to the cavity The internal materials are required to cool and shrink the materials to avoid defects such as shrinkage of plastic products.

(4) Cooling and pre-plasticization process Once the gate is sealed, the holding pressure process is cancelled, and the product is naturally cooled and shaped in the mold; at the same time, the pre-plasticizing oil motor is driven to rotate the screw to convey the granular plastic from the hopper forward, and Plasticizing. After the plasticization of the raw material reaches a predetermined metering value, in order to prevent the melted plastic from overflowing the nozzle, the screw needs to be moved backward a certain distance, that is, the anti-delay treatment is performed.

(5) After the injection device withdraws, opens the mold, and ejects the plastic product after the pre-plastic measurement and anti-rolling process is over, in order to prevent the nozzle from forming cold materials due to contact with the cold mold for a long time, the nozzle is usually removed from the mold. That is, the injection device is retired. Whether the action is performed and the sequence of execution can be selected. Once the product is cooled and shaped, open the mold and eject the product.