What is the reason why the plastic extruder does not discharge material?

Plastic extruders are generally divided into single-screw extruders and twin-screw extruders. In the actual use of plastic extruders, sometimes there is a problem of not discharging material, which will bring the entire production to a standstill and must be solved immediately. East Point Machinery has sorted out the main reasons why the plastic extruder does not discharge material, hoping to help you solve the problem quickly.
The reason why the extruder does not discharge material is actually very simple. The main reasons are: excessive pressure in the extruder barrel, the feeding speed of the feeding system cannot keep up with the production needs, damage to the barrel or screw, and out-of-control barrel temperature control, etc. .
1. The pressure inside the barrel is too high
The pressure inside the extruder barrel is too high. When the pressure is greater than the conveying pressure provided by the screw to the material, the material does not have the ability to be extruded from the die. There are many reasons for this situation, but most of them are attributed to the failure of the extruder die section. For example, when the material contains materials that cannot be melted during the reproduction process (it may also be that the normal material in the barrel has not been plasticized because the equipment temperature is not up to standard), it may block the outlet of the mold, and the final result is increased Increase the pressure inside the barrel.
2. The feeding speed of the feeding system is slow
When each piece of equipment leaves the factory, the feeding system is able to meet the production needs of the equipment. If this happens, there must be an abnormal failure. The feeding stage that can directly affect the feeding of the extruder is the storage hopper of the extruder. The storage hopper can be divided into two types: ordinary hoppers that rely on gravity feeding and forced feeding hoppers that rely on mechanical transmission. The most common point of feeding materials using the principle of gravity is an ordinary conical or similar structure hopper. If the feeding speed is slow, the material may be bridged in the hopper or unqualified materials may be replaced (the hopper cannot adapt to production).
3. Barrel or screw damage
The barrel and screw are important core components of the extruder and are directly related to material processing. When the material melts in the compression section of the screw, it adheres to the barrel wall. When the screw rotates, the material leaves the barrel wall and is transported forward after being subjected to shear force. If there are wear areas on the screw and barrel, and the material cannot be sheared well away from the barrel wall, the screw cannot effectively transport the material forward.
4. Barrel temperature control is out of control
Loss of barrel temperature control can be called a devastating failure in the production process of plastic extruders. In fact, it can be divided into many aspects and will not be elaborated here. Temperature causes the extruder to fail to discharge material. Generally speaking, it means that the temperature of the barrel feed section is too high. Everyone knows that large-sized extruders are usually equipped with forced cooling devices in the feeding section. If the temperature in this area is too high, the material may be rapidly plasticized by heat after entering the barrel, ultimately affecting the feeding speed of the equipment. In the end, the equipment does not discharge materials.
East Point Machinery reminds that there are many reasons for the failure of plastic extruders to discharge material. Here are only common reasons, which require detailed analysis of specific problems. For example, when processing hygroscopic materials: incorrect material drying will cause It significantly reduces the viscosity of the material in the barrel and produces water vapor, making it difficult for the screw to transport the material forward. So don't copy it mechanically. If you encounter problems, you are welcome to call us for consultation.