SDJ Two-Stage Extrusion Pelletizing Line for Heat-Sensitive Polymer Compounding

Hi everyone,

Many compounding manufacturers struggle with a common headache: heat-sensitive polymer materials degrade easily under continuous high shear during granulation. Once overheating occurs, the final pellets will have discoloration, poor physical performance, unstable quality, and huge waste of raw materials. This is especially obvious when producing XLPE, PVC, halogen-free flame retardant cable compounds and shielding materials.

Today we want to introduce our SDJ Series High Kneading Two-Stage Extrusion Pelletizing Unit, a T-type layout compound system built to solve the overheating problem for heat-sensitive formulations and high-volume devolatilization processing.

Machine Structure

This two-stage line adopts a T-shaped composite layout:

• First stage: TSB / TSH high-speed co-rotating twin-screw kneader, responsible for forced feeding, plasticization, mixing, shearing and dispersion. No head backflow, which greatly cuts extra shear heat.

• Second stage: SE series low-speed single-screw extruder, delivering stable high-pressure extrusion at low shear to avoid secondary overheating.

The two stages work independently and coordinatively, combining the strengths of twin screw and single screw extruders.

Core Advantages

1. Complementary performance, avoid material overheatingThe twin-screw section completes intensive mixing and dispersion without back pressure reflux. The single-screw section provides steady pressure extrusion at low speed & low shear. The two sections work together to balance mixing quality and temperature control, effectively preventing thermal degradation of sensitive polymers.

2. Separated process for flexible adjustmentThe twin screw and single screw split the whole compounding workflow. More independent adjustable parameters are available. You can optimize kneading and extrusion separately, making the production process predictable and easy to fine-tune for different recipes.

3. Higher throughput & continuous productionFull continuous workflow supports large-batch standardized compounding. Hourly output is significantly improved, perfect for cable material, shoe foam compound and rubber post-treatment mass production.

Typical Application Materials

Our SDJ two-stage pelletizing machine is specially developed for heat-sensitive polymers and high-capacity devolatilization:
PVC, XLPE, halogen-free flame retardant cable compound, shielding compound, shoe sole foaming material, rubber post-treatment and related modified plastic formulations.

SDJ Model & Throughput Reference

• SDJ-65/150: 500–600 kg/h

• SDJ-75/180: 800–1000 kg/h

• SDJ-85/200: 1200–1500 kg/h

• SDJ-95/250: 1500–2000 kg/h

• SDJ-115/300: 3000–4000 kg/h

We also supply integrated internal mixer two-stage pelletizing lines as an alternative solution for higher kneading demand. All lines support customized configuration according to your material formula, target output and factory layout.

If you are looking for a reliable compounding system for cable materials or heat-sensitive modified plastics, send us your material sheet and required capacity. We can provide a customized technical proposal for your project.

What material do you usually run and what is your biggest challenge in controlling melt temperature during pelletizing? Welcome to share your experience below.

http://www.yuzunextruder.com
Nanjing Yuzun Machinery Technology Co., Ltd.