Solving PET Foaming Difficulties: Full-Length Solutions of Domestic Integrated Production Lines

Introduction
Insufficient melt strength of neat PET easily causes cell collapse, restricting large-scale manufacturing for a long time. This paper analyzes universal industrial improvement solutions and the core strengths of integrated complete lines consisting of PET Foam Sheet Extruders, Two-Stage Supercritical CO₂ Foaming Production Lines and PS Foam Recycling Pelletizers.

1 Core Industrial Bottlenecks of PET Foaming
Linear PET features short molecular chains and low melt strength. Bubbles tend to rupture and collapse during foaming expansion, resulting in uneven cell size and deteriorated mechanical performance. The industry adopts a dual solution of formula modification and equipment upgrading:
(1) Formula modification: branching agents and nucleating agents are added to widen the applicable foaming temperature range by 30°C and improve production tolerance;
(2) Equipment structural optimization: twin-screw units combined with static mixers ensure uniform melt blending, while segmented independent temperature control precisely matches foaming temperature zones;
(3) Two-stage supercritical process: CO₂ saturation proceeds under low temperature and high pressure in the first stage, followed by slow foaming with back pressure in the second stage, forming stable honeycomb microcells and enhancing fatigue resistance and compressive performance.

2 Configuration of Domestic Integrated PET Foaming Production Lines
A complete closed-loop line consists of three core devices: PET Foam Sheet Extruder, Two-Stage Supercritical CO₂ Foaming Production Line, and PS Foam Recycling Machine, realizing full automation from raw material feeding to extrusion foaming, sheet cutting and waste regeneration.
Four Core Equipment Advantages
(1) Drying-free extrusion design: eliminates pre-crystallization and drying steps for PET, lowering equipment investment and power consumption;
(2) PLC servo linkage: multiple groups of temperature and pressure parameters can be stored and recalled with one click for quick switching between foams of different densities;
(3) Modular rapid mold change: a single line flexibly produces wind power core materials, new energy battery insulation boards and rail transit interior panels;
(4) Integrated online recycling: sheet scraps are crushed on-site and fed into the PS Foam Recycling Pelletizer for melt re-granulation, sharply cutting raw material loss.

3 Future Intelligent Upgrading Directions for Equipment
(1) AI adaptive process adjustment: screw speed and CO₂ injection pressure are automatically corrected according to melt status;
(2) Remote operation & early warning: equipment faults are monitored in real time with online parameter debugging to reduce downtime;
(3) Multi-material compatible lines: a single Two-Stage Supercritical CO₂ Foaming Production Line can switch between virgin PET, recycled PET and biodegradable PLA.

Conclusion
Domestic complete foaming equipment has broken overseas technological monopolies. By jointly optimizing formulas and machinery to eliminate PET cell collapse defects, matched with waste recycling auxiliary machines, they provide low-cost, low-carbon full-process production solutions for lightweight manufacturers.