Pipe Extrusion Operation: Best Practices for High-Quality Products

Date:2023-4-04 Author:hcscrew

Learn the best practices for PVC pipe extrusion operation to produce high-quality products that meet industry standards. Our expert guide covers everything from selecting the right screw barrel and twin screw extruder to optimizing processing parameters for maximum efficiency. Discover the secrets to success and improve your PVC pipe extrusion operation today.

If you’re in the business of manufacturing PVC pipes, you know that high-quality products are essential for customer satisfaction and repeat business. One critical factor in producing high-quality PVC pipes is the extrusion process. Proper extrusion process operation is essential to producing PVC pipes that meet or exceed customer expectations. In this article, we’ll discuss the best practices for PVC pipe extrusion operations to produce high-quality products.

Proper Material Handling

The first step to a successful PVC pipe extrusion operation is to handle the material properly. Screw barrel and twin screw extruders are sensitive to impurities in the materials used for PVC pipe extrusion. Therefore, storing and handling materials correctly is crucial to prevent contamination and ensure consistent quality. Materials should be stored in a clean, dry environment and handled with care to avoid damage. Additionally, it’s important to select the right materials for specific extrusion applications, considering factors such as heat resistance, chemical resistance, and strength.

Setting up the Extruder

The extruder’s setup is also critical to producing high-quality pipes. The appropriate die and screw design should be selected for the specific application. Screw barrel design is crucial for the quality of extruded PVC pipes. A high-quality screw barrel provides consistent and accurate output, which is essential for producing high-quality pipes. Proper screw speed and temperature settings are essential for the desired product characteristics. Improper screw speed or temperature settings can cause uneven melting or cooling, leading to product defects.

Extrusion Process Parameters

Monitoring and adjusting the extrusion process parameters is essential for producing high-quality pipe. The melt temperature, pressure, and cooling rate are the critical parameters to measure and adjust. The melt temperature should be set correctly to ensure consistent viscosity and flow. The pressure should be monitored to avoid over-pressurizing the system, leading to pipe deformation or failure. The cooling rate is crucial for achieving the desired product characteristics. Monitoring the cooling rate ensures that the PVC pipe is cooled uniformly, avoiding stress and deformation.

Post-Extrusion Processing

Post-extrusion processing is another critical step in producing high-quality PVC pipes. Proper cutting, cooling, and handling of the extruded product are essential to avoid damage and ensure consistent quality. Proper downstream processing ensures the PVC pipe is cut to the right length, cooled uniformly, and handled carefully to avoid damage. Additionally, quality control measures such as testing for leaks, diameter consistency, and wall thickness should be performed to ensure that the extruded pipe meets specifications.

PVC pipe extrusion operating procedures

(1) Operation before starting the machine

①The material used for extrusion molding should be beaten to the required drying requirements, and further drying is needed if necessary.

②Turn on the water, electricity, and gas, turn on the power of the main machine, and start to raise the temperature, according to the process requirements to the set temperature, and wait for the temperature to reach the set value of constant temperature for 30 min.

③According to the type and size of the product, select the head specification, replace the mould (do not collide with the internal and external surfaces of the mouth mould and core mould), sizing sleeves, cooling water ring, cooling flange, bracket, sealing rubber gasket, adjust the position of the cutter, replace the cutter chuck, adjust the length of the cutter and the length of the flap.

④Prepare the traction pipe.

(2) Start-up operation

Start-up is an important part of the production. Poor control will damage the screw and head, the temperature is too high will cause plastic decomposition, and the temperature is too low will damage the screw, barrel and head. The steps to start up the machine are as follows:

① start the machine at a low speed, idle, check the screw for abnormalities and motor amperage meter for overload, the pressure gauge is normal, and the machine should not be airborne for too long, to prevent the screw and barrel scraping and grinding.

② gradually add a small amount of material to be squeezed out of the die, before normal feeding, before the material is extruded, no one shall be in front of the die, to prevent casualties.

③After the plastic is extruded, it is necessary to slowly lead the extruded material onto the cooling and shaping and traction equipment. It is also necessary to start this equipment beforehand. Afterward, each link will be adjusted according to the control instrument’s indication value and the extruded product’s specifications. As long as the extrusion operation is normal, this will be done.

④Cutting and taking samples, checking whether the product’s appearance meets the requirements, and whether the size of the product fits the standard. Then quickly testing the performance, and then adjusting the extrusion process according to the quality requirements to make the product meet the standard requirements.

⑤ Start the human-machine interface of the extruder, start the main machine through the human-machine interface of the extruder, and control the speed at 10-30r/min.

(3) Stop the operation

Stop feeding, squeeze out the material in the extruder, and turn off the power of the barrel and head for the next operation.

① Turn off the power of the main machine and at the same time, turn off the power of each auxiliary machine.

②Open the connection flange of the head and clean the porous plate and the various parts of the head. Use copper rods and pieces to clean the machine, and apply a little oil after cleaning.

③ screw, barrel cleaning if necessary, the screw can be taken out, and clean up after recovery, in general, can be used in the transition to material cleaning method.

④ The extrusion of polyolefin plastics is usually done with a full stop (with material stop), where air should be prevented from entering the barrel so as not to oxidize the material. For polyvinyl chloride plastics, it can also be used to stop with material, then close the material door, reduce the temperature at the head connection body (flange) by 10-20℃, and stop the machine after the material is squeezed out.

⑤ Close the total power supply and the total cooling water valve.

Process control points

Temperature control, screw speed, and cooling temperature control, traction speed control, compressed air control, etc., are major elements of the pipe’s process control.

Maintenance and Safety

Regular maintenance and safety procedures are essential for prolonging screw barrel and twin screw extruder lifespan and ensuring safety. Regular maintenance and cleaning of extrusion equipment prevent common equipment failures, leading to reduced downtime and higher productivity. Proper safety procedures such as wearing protective gear and avoiding contact with hot components are essential for preventing accidents.

Conclusion

In conclusion, pipe extrusion operation is a critical factor in producing high-quality pipes. Proper material handling, extruder setup, extrusion process parameters, post-extrusion processing, and maintenance and safety procedures are all essential for producing high-quality products. Screw barrel and twin screw extruders play a crucial role in PVC pipe extrusion operation. Selecting the right equipment and following the best practices will help ensure success.

About the twin screw barrel Factory: HUACHEN

HUACHEN Screw has been a leading twin screw barrel manufacturer in Zhoushan Jintang since 1993. As one of the leading companies in designing and processing parallel and conical twin screw extrusion screw barrel, HUACHEN Screw can provide its customers with a wide range of services, including drawing rebuilding, design, modification, and customized screw barrels. Our company has also successfully exported and supplied screw barrels to customers worldwide.

>>Learn more about our company

	PVC Pipe Conical Twin Screw Barrel ↗ Get PVC pipe conical twin screw barrel details and prices from HUACHEN screw barrel factory. Good plasticisation, heavy duty screw barrel.
	Conical Twin Screw Barrel ↗ Get latest & most competitive prices on China conical twin screw barrel, extruder barrels, extruder screw, bimetallic screw, SKD barrels…
	Twin Screw Barrel ↗ Get latest good prices on China twin screw barrel, parallel conical twin screw barrel. Advantages, comparisons, materials, models…

Solutions