Reasons and solutions for too little extrusion of high-speed injection molding machines

2021-05-28 11:06

Today, let's talk about the reasons and solutions for the low extrusion volume of high-speed injection molding machines.

Customers often report that the extrusion volume of the high-speed injection molding machine gradually decreases after a period of use, mainly due to the following reasons.

The first reason is that the cold air has been blowing for a long time, which causes the surface of the mold to be too cold.

At this time, it is necessary to check whether the rubber at the exit of the mold surface has been plasticized and melted.

The second reason is that the startup temperature is too low.

Is this the time to check whether the temperature of each part of the extruder barrel and die meets the standard requirements? Although the outdoor temperature of each part is up to the standard, if the heating time is not enough, the temperature inside and outside will be different; check whether there is any damage to the heater or thermocouple. If any electrical component is damaged, repair or replace it immediately.

The third reason is that the temperature of the extruder barrel or die is too high, the screw and barrel of the melting section are worn, the screw is carbonized, and the material is not discharged normally.

Check the sensitivity of the thermostat and handle it properly, the die thermostat should be more sensitive.

The fourth reason is that the drive belt is loose or dislodged.

The old drive belt should be replaced with a new one immediately, and an idler pulley should be installed to adjust the belt tension and prevent the belt from loosening and falling off again.

The fifth reason is glue sticking in the screw feed section.

Before each shutdown, lower the temperature slightly; wait until the screw feeding part is completely free of glue and then shut down; after starting the machine, if there is a screw glue failure, clean the screws first, which is inconvenient to clean, and use plastic rods or wooden sticks at the feeding port Squeeze the material hard, so that the sticky screw is inserted into the rubber material part to move forward. At this time, pay attention to the plastic rod or the wooden rod being bitten by the screw, otherwise the wooden block will fall off, and do not use the metal rod.

The sixth reason is that there is a glue block in the throat of the filling barrel.

The cooling water jacket at the throat of the filling barrel is controlled below 40°C. If the filter is clogged, please replace it with a new filter in time.

The seventh reason is that the back pressure is too low.

The phenomenon caused by too low back pressure is material instability, which can be corrected by increasing the back pressure.

The eighth reason is that the voltage fluctuation of the DC motor is too severe. A voltage stabilizer should be installed to ensure voltage stability.

The ninth reason is that the clamping speed is not uniform or the pressure between the rolls is too high.

Now is the time to check if the clamping lever is off-centre. There is no wear or slack in the drive belt; if the roller pressure is too low, slippage will occur, and the air pressure can be adjusted or the spring can increase the pressure.

The tenth reason is that too much recycled material is mixed in the crushing.

If the crushed material needs to be added, it is best to granulate it first to stabilize the discharge.

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