Solid State Polymerization (SSP)

The Solid State Polymerization (SSP) process refers to the condensation polymerization of solid chips, aimed at increasing molecular weight and intrinsic viscosity (IV). The normal PET Chips are heated to the glass transition temperature (usually 10-40° C below the melting point). The small molecular products are removed by vacuum or inert gas protection (generally high-purity nitrogen), so the polycondensation reaction continues and the viscosity increases further. End Carboxyl (COOH) content decreases when IV content increases. This process can be used to produce various bottle-grade, industrial filament-grade, low-end group-content (low CEG) PET chips, as well as thermal- and hydrolysis-resistant PET resin. SSP can be classified as continuous or batch, depending on the process.

In production, the right SSP technology makes all the difference. We provide two core solutions tailored to your needs, whether for laboratory-scale development or full-scale industrial production.

1. Batch SSP System (Rotary Drum)

Production Capacity

1 – 20 Tons / Batch

Key Advantages:

High Versatility: Perfect for specialized polymer grades requiring frequent parameter adjustments.

Optimal for R&D: Cost-effective solution for small-batch and niche market production.

Core Process Units:

Rotary Drum System: Multi-functional unit for crystallization, drying, and polymerization.

High-Vacuum System: Ensures purity by efficiently removing reaction by-products.

Thermal Oil Unit: Precision temperature control for consistent product quality

2. Continuous SSP System

Daily Capacity

15 – 750 Tons / Day

Key Advantages:

Superior Consistency: Uniform crystallization for stable, high-quality output.

Clean Production: Optimized processes result in significantly lower dust content.

Energy Efficient: Lower power consumption compared to traditional methods.

Process Components:

Crystallizer & Preheater: Prevents agglomeration and boosts efficiency.

SSP Reactor: Precision IV (viscosity) control for tailored product specs.

Nitrogen Purification: Closed-loop system for continuous impurity removal.

Smart Control System: Real-time monitoring with advanced data logging

Our factory has installed one batch SSP equipment (10 tons/batch) and two continuous SSP equipment (30 tons/day and 50 tons/day). With the equipment, we have successfully customized high-IV and low-COOH PET for our domestic and overseas customers. Below are the specs for your reference. If you have any inquiries, please feel free to contact us.