Nine common faults and solutions of injection molding machines

1、 The oil pump motor and oil pump start, but do not generate pressure.
1. The proportional valve wiring on the oil pump is loose or the coil is burnt out - check if the proportional pressure valve is energized.
2. Impurities block the proportional pressure valve port on the oil pump - remove the proportional pressure valve to remove impurities.
3. The pressure oil is unclean and debris accumulates on the surface of the oil filter, preventing the pressure oil from entering the pump - clean the oil filter and replace the pressure oil.
4. The internal oil leakage of the oil pump is caused by excessive use, internal loss, or damage caused by unclean pressure oil - repair or replace the oil pump.
5. Oil pump barrel, oil pipe, and joint leakage - eliminate leakage areas.
6. Oil system stuck - Check if the oil system valve core is functioning properly.
2、 The temperature of the glue cylinder cannot be controlled
1. The temperature cannot be controlled. Check if the contacts of the electric contactor are stuck, and if the wires of the thermocouple are loose or damaged.
2. If the temperature cannot rise, check whether the electric air switch inside the electric box has tripped, whether the contactor and relay are closed, whether there is voltage, whether the fuse is burnt out, and whether the heating ring is burnt out.
3. Is the temperature gauge damaged.
3、 Non locking mode
1. Whether the front safety door has been closed, whether the limiter of the safety door has been pressed and released, and whether the wiring is loose or damaged.
2. The coil of the mold locking electromagnetic system may have moved towards the valve and stuck the valve core - clean or replace the mold locking and opening control valve.
3. The directional valve may not reset - clean the directional valve.
4. The ejector pin cannot be returned and reset - check if the ejector pin action is normal.
5. Check whether the origin of the computer controller's locking and opening electronic ruler has changed, and whether the locking position has been terminated.
6. Check if the pressure gauge is working.
7. Press the lock button to check if the display screen displays a lock signal or other signals and alarms.
8. Check whether the position, speed, and pressure of the locking mold are adjusted properly.
9. Check if the piston rod of the locking mold is broken.
4、 Non adhesive
1. The coil made of glue injection solenoid may have burned or foreign objects may enter the directional valve, causing it to move due to jamming the valve core - clean or replace the glue injection valve.
2. Low pressure - increase the injection pressure.
3. The temperature during injection molding is too low - adjust the temperature gauge to raise the temperature to the required point. If the temperature gauge still cannot raise the temperature, check whether the electric heating cylinder and fuse are burnt or loose. If they are broken, replace them in a timely manner.
4. Loose or poor connection of the injection combination valve opening system wiring - connect the combination switch wire properly.
5、 The glue screw rotates, but the glue does not enter the barrel
1. The backpressure of the adhesive is too high, and the backpressure valve is damaged or improperly adjusted - adjust or replace the adhesive backpressure valve.
2. Insufficient water transportation, even if the temperature is too high, hinders the entry of rubber particles into the screw - adjust the water transportation volume and remove the bonded rubber block. Check if the water transport ring is blocked or if there is no cooling water.
3. No material inside the hopper - feeding.
4. Is the temperature of the glue cartridge too high.
6、 The shooting platform does not move
1. The limit travel switch of the shooting table movement is adjusted and the collision block is pressed - adjust.
2. The coil of the moving electromagnetic valve on the shooting platform may have burned or foreign objects may enter the direction valve, causing the valve core to move. Clean or replace the electromagnetic valve.
3. Check if the forward speed and pressure of the shooting table are improperly adjusted.
4. Check if the output voltage (DC+24V) of the 1/0 board and directional valve is normal. If not, check if the corresponding output transistor or relay is damaged.
5. Press the shooting button to check if the computer display screen displays the shooting signal before the shooting platform, or other signals and alarms.
6. Check if the pressure gauge is functioning properly.
7、 Make a sound when opening the mold
1. The mold opening stroke switch is not stuck or the card is malfunctioning - adjust or replace the solenoid valve.
2. Loosen the fixing screw of the slow solenoid valve, or the valve core is stuck - adjust to a noticeable slow speed.
8、 Pressure oil temperature too high
1. The oil pump pressure is too high - it should be adjusted to the required pressure of the rubber material.
2. Oil pump damage and low pressure oil concentration - check the oil pump and oil quality.
3. Insufficient pressure oil volume - increase the pressure oil volume.
4. There is a problem with the cooling system causing insufficient water supply - repair the cooling system.
9、 Full automatic action failure
1. The malfunction of the electric eye, loose fixing screws or poor focusing may cause it to restore its function.
2. Time system malfunction or damage - adjust or replace the time system.
3. The heating cylinder is damaged - replace it.
4. Poor or damaged thermocouple wiring - tighten or replace.
5. Damaged temperature gauge - Replacement 10. Semi automatic malfunction: Semi automatic cycle is achieved by the mechanical action of the stroke, triggering various electrical switches and time systems, issuing electrical signals, and controlling the oil system. If in manual mode, each action is normal, while the semi-automatic malfunction is mostly due to the failure of electrical switch and time systems to send signals. First, observe at which stage the semi-automatic action fails, Identify the corresponding control components according to the "action cycle diagram" and conduct inspections to solve the problem.