What is the Extrusion Process of PVC Pipe

What is PVC pipe?

PVC pipe is a widely used type of plastic pipe. Its main raw material is polyvinyl chloride, a strong, durable, corrosion-resistant, and inexpensive material.

 

Extrusion Process of PVC Pipe

Main Classifications of PVC Pipe:

UPVC: Plasticizer-free, relatively rigid, and the most common type. Primarily used for water supply, drainage, and electrical wiring protection.

CPVC: Chlorinated, more heat- and pressure-resistant, suitable for hot water transportation and industrial piping.

Extrusion Process of PVC Pipe:

The extrusion molding of PVC pipes is a complex physicochemical process. Its core is to heat and melt the PVC mixture through an extruder, plasticize it, shape it in a mold, and finally cool and cut it into pipes.

1. Raw Material Preparation and Mixing

This stage is the foundation for ensuring the pipe’s performance. Precisely measured PVC resin and additives, such as stabilizers and lubricants, are fed into a high-speed mixer for heating and stirring to achieve initial plasticization and uniformity. The mixture is then immediately transferred to a cooling mixer to lower its temperature and prevent clumping, resulting in a ready-to-use dry blend powder.

 

Extrusion Process of PVC Pipe

 

2. Extrusion and Plasticization

The blended powder is fed into the PVC pipe extruder‘s hopper. Inside the heated barrel, the material is gradually melted into a uniform viscous fluid through the shearing and compressing action of the rotating screw, a process known as plasticization. Twin-cone screw extruders are currently the mainstream equipment for this, as they achieve efficient and homogeneous plasticization.

3. Molding and Shaping

Molten PVC passes through a ring-shaped pipe die head to form a hollow pipe blank. Immediately afterwards, the pipe blank enters a vacuum sizing sleeve, where, under negative pressure and cooling water, it is given a precise outer diameter and undergoes initial solidification and shaping.

 

Extrusion Process of PVC Pipe

 

4. Cooling and Haul-Off

The shaped pipe enters a cooling tank for thorough water cooling, ensuring complete solidification. Simultaneously, a haul-off machine pulls the pipe at a constant speed synchronized with the extrusion speed, guaranteeing continuous, stable production and a uniform wall thickness.

 

Extrusion Process of PVC Pipe

 

5. Cutting and Packaging

Once the fully cooled pipe reaches a set length, it is cut by an automatic cutting device. Rigid pipes are cut to length and stacked, while flexible pipes may be coiled. Finally, the finished products are inspected, marked with information like specifications, and then packaged for storage.

About Kangju Machinery:

Kangju Machinery Co., Ltd. is located in Suzhou Zhangjiagang, specializes in manufacturing high-quality plastic extrusion production line. Including: PE HDPE PVC PPR pipe extrusion line, PVC WPC profile production line, PVC WPC board / panel extrusion line, plastic sheet extrusion making machine.

 

Why choose Kangju Machinery?

Planning a plant is complex, but partnering with Kangju Machinery simplifies the transition from blueprint to production. With over 15 years of specialized experience in plastic extrusion line, Kangju does not just supply machines; we deliver “Turn-key Intelligence”.

  • 15+ Years of Technical Mastery: Proven expertise in pipe / profile / panel / sheet extrusion.
  • Customized Molds: Our in-house mold design team uses flow-simulation software. This ensures your PVC wall panels have uniform thickness and a flawless finish from the first meter.
  • On-Site Commissioning: We provide global on-site installation and technician training, ensuring your local team is fully capable of maintaining peak production efficiency.

Kangju Machinery

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