The extruder is a common plastic machinery. During the daily operation of the extruder, there are various failures in the extrusion machine, which affects the normal production of plastic machinery. Below we analyze the failure of the extruder.

Common faults and treatment methods of rod extruder

1.1, abnormal noise

(1) If it occurs in the reducer, it may be caused by damage to the bearing or poor lubrication, or it may be caused by gear wear, improper installation adjustment or poor meshing. It can be solved by replacing the bearing, improving the lubrication, replacing the gear or adjusting the meshing condition of the gear.

(2) If the noise is a sharp scraping sound, the position of the barrel should be considered to be skewed, which may cause the shaft head and the transmission sleeve to be scraped. Can be solved by adjusting the barrel.

(3) If the barrel emits noise, it may be a screw bending broom or setting the temperature too low to cause excessive friction of solid particles. It can be handled by straightening the screw or increasing the set temperature.

Abnormal vibration

If this happens at the reducer, it is caused by the wear of the bearing and the gear. It can be replaced by a replaceable bearing or gear. If it occurs at the barrel, it is because the material is mixed with hard foreign matter, and the material should be inspected for cleaning.

The main reason and solution for the wear of screw extruder

2. The main reason for the wear of the screw extruder

The normal wear of the screw and barrel of the screw extruder mainly occurs in the feeding zone and the metering zone. The main cause of wear is caused by the friction between the sliced ​​particles and the metal surface. When the temperature of the slice is softened, the wear is reduced.

Abnormal wear of the screw and the barrel will occur when the screw loop and the foreign matter are stuck. The loop knot refers to the screw being condensed by the condensed material. If the screw extruder lacks a good protection device, the strong driving force may be broken. Screws, stuck, can create unusually large resistance, causing serious damage to the surface of the screw and severe scratching of the barrel. Scratching of the barrel is difficult to repair. The barrel is designed to ensure that the service life is longer than the screw. For the normal wear of the barrel, it is generally not repaired. The method of repairing the screw thread is often used to restore the radial clearance between the barrel L and the outer diameter of the screw.

3. Screw wear solution

The local damage of the screw thread is repaired by surfacing the special anti-wear alloy. Inert gas shielded welding and plasma argon arc welding are generally used. Metal spray technology can also be used for repair. Firstly, the outer surface of the worn screw is ground to a depth of about 1.5 mm, and then the alloy layer is surfacing to a sufficient size to ensure sufficient
The machining allowance, finally grinding the outer circumference of the screw and the side of the thread to the outer dimensions of the screw is the original size.

4. Ring plugging at the screw inlet

This kind of failure is mainly caused by the cooling water interruption or insufficient flow. It is necessary to check the cooling system and adjust the cooling water flow and pressure to the specified requirements.

in conclusion

(1) The natural life of the extruder is long, and its service life mainly depends on the wear of the machine and the wear of the gear box. Choose design materials and well-made extruders and reducers to directly shut down

To the use of performance, although equipment investment increased, but the service life is extended, from the overall economic benefits, it is more reasonable.

(2) The normal use of the screw extruder can fully exert the performance of the machine and maintain a good working condition. It must be carefully maintained to extend the life of the machine.

(3) The main failures of screw extruders are abnormal wear, foreign matter jamming, blockage of materials, wear or damage of transmission components, poor lubrication or oil leakage. In order to avoid failures, the drying, mixing and feeding operations and process temperature settings must be strictly managed, and daily maintenance, maintenance and overhaul should be carried out in strict accordance with the requirements of the Equipment Inspection Base.

Extruder feed roller wear

Since the extruder is made of metal, the hardness is high, and it is subjected to vibration shock and other compounding forces during production and operation, resulting in gaps between the components and causing wear.

The traditional repair methods include surfacing, thermal spraying, brushing, etc., but several methods have certain drawbacks: surfacing will cause the surface of the part to reach a very high temperature, causing deformation or cracking of the part, affecting dimensional accuracy and normal use. In severe cases, it will lead to breakage; although the brush crossing has no heat effect, the thickness of the crossing layer should not be too thick, the pollution is serious, and the application is also greatly limited. Western countries have applied the polymer composite method to the above problems.

Its comprehensive performance and mechanical machining characteristics at any time can meet the requirements and accuracy after repair, and can also reduce the shock and vibration of the equipment during operation and prolong the service life. Because the material is a "variable" relationship, when the external force impacts the material, the material will deform and absorb the external force, and will expand and contract with the expansion or contraction of the bearing or other components, and always maintain a tight fit with the component to reduce the chance of wear. For the wear of large extruders, “mold” or “mating parts” can also be used for on-site repair of damaged equipment, avoiding the overall disassembly of the equipment, maximizing the fit size of the parts and meeting the production and operation requirements of the equipment.

The processing section of the feeding section of the extruder does not match the processing size.

When the material of the extruder bushing is 38CrMoAlA, due to machining reasons (the positioning keyway and the mating part are not on one axis), there is a matching clearance between the joint plate and the side plate (material 40Cr or 45). Leakage due to the action of the recoil of the rubber. The temperature does not exceed 100 °C. The company has previously repaired other products, only 1 to 2 days, the use of polymer materials repair can solve this problem.

Extruder feed section side cover thread damage (sliding wire)

During the pre-tightening of the bolt, the bolt is deformed by the tensile stress, and its restoring stress is tightly connected with the sealing part to which it is attached, and is stretched over time, partially stretched and deformed. It becomes permanent deformation, and the stress is reduced. As a result, stress relaxation and torque drop occur, and bolt looseness occurs, causing the wire to wear the thread, and even causing damage to the internal thread of the fastened component. It is repaired with Mikawara polymer materials, which has the concession of metal, which guarantees the recovery stress after repair and ensures the use of components.

At the same time, the non-metallic nature of the material itself makes it more sturdy than metal, eliminating the damage caused by loosening and ensuring the safe and continuous production of the enterprise.

Dongguan Pinyang Cable Machinery Co., Ltd. is a professional manufacturer of wire and cable equipment for professional development, design and production. It specializes in: optical fiber extruder, ultra-fine winding machine, earphone wire special machinery and other products, optical fiber extruder, very fine winding Machine, earphone line dedicated mechanical consultation hotline: 13731224526 / Lu Jianjun