A Professional Guide to 10 Technical Questions on Pipe Extruder Functions and Configurations

Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with over 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.

Recently, common issues regarding extruder functions and configurations encountered during operation have been collected. Professional advice from relevant experts has been provided, and this guide serves as a reference. Experts are welcome to offer further corrections or comments.

1. What are the feeding systems used in extruders?

For conical twin-screw extruder production lines, the main feeding systems include:

Spring feeder

Screw feeder

Vacuum powder feeder

For single-screw extruder lines: vacuum pellet feeder.

2. What feeding modes are generally used for conical twin-screw and single-screw extruders?

Conical twin-screw extruders use a twin-screw feeding system to reduce bridging (bridging refers to powder particles rubbing against each other, generating static electricity and causing material to clump together).

Single-screw extruders primarily use gravity feeding (loss-in-weight), and a gravimetric (mass flow) system may also be used, which is also a form of loss-in-weight feeding.

3. Why is a vacuum venting system necessary for twin-screw extruders during production?

Powder materials readily absorb moisture from the air, so the extruder requires vacuum venting to prevent this from affecting the quality of the final product.

4. What materials and structures are used for PP and PE pipe sizing sleeves?

PP and PE pipe sizing sleeves are made of copper. The disc-type sizing sleeve offers good cooling and is suitable for high-speed extrusion of PE/PP pipes at speeds of 8 m/min or more. A standard copper sizing sleeve has grooves that allow vacuum to draw the pipe against the sleeve while also permitting cooling water to enter.

5. What materials are used for PVC pipe sizing sleeves?

PVC pipe sizing sleeves can be made of copper (for faster cooling) or stainless steel (for wear resistance).

6. What are the specifications of single-screw extruder main units, including corresponding motor power ratings and pipe diameter ranges? What are the main components of a single-screw extruder?

The main unit includes:

Motor brands: Siemens, Beide, Wannan, WEG

Gearbox: Guomao, Duoling

Barrel and screw: 38CrMoAlA; manufacturers: Jinghong, Huaye, Jinteng, Jinjiu

Heaters: ceramic or cast aluminum; manufacturer: Luhao

Fans: Suzhou Aoke, Taiwan Sanyue

Electrical components:

– Inverters: ABB, Japan Yaskawa

– Low-voltage components: Schneider, Siemens

– Solid-state relays: France Celduc, Switzerland Carlo Gavazzi, Italy Gefran

– Circuit breakers: LS, Schneider

7. What are the drainage methods for vacuum tanks?

Manual drainage and temperature-controlled drainage (mechanical expansion valve, pneumatic angle seat valve).

8. What types of pipe cutters are available, and what are their advantages?

– Pivot cutter: Suitable for small-diameter pipes and profile cutting; produces chips.

– Planetary cutter: Advantage – capable of cutting pipes of various sizes except small diameters.

– Chipless cutter: Advantage – no chips produced.

9. What surface treatments are applied to molds?

Hard chrome plating is applied to the surface, which improves surface hardness, wear resistance, and corrosion resistance.

10. What are the main differences between a high-efficiency PE pipe line and a standard PE pipe line?

The higher efficiency of a high-efficiency pipe line is achieved by increasing the screw speed, thereby raising the extruder output.

If you need more information, Ningbo Fangli Technology Co., Ltd. welcomes you to contact for a detailed inquiry, we will provide you with professional technical guidance or equipment procurement suggestions.