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Overview of SSP System

This document serves as a professional technical guide for industrial Solid State Polymerization (SSP) systems, focusing on the core function of upgrading PET (Polyethylene Terephthalate) material performance. It details modular configurations, technical parameters, and application value, tailored for high-end PET production scenarios such as bottle-grade, fiber-grade, and sheet-grade recycling and processing.

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    • Equipment Nature: A continuous industrial system designed to increase the intrinsic viscosity (IV) of PET chips/pellets via solid-state polycondensation (no melting, temperature below Tm ~250°C); critical post-crystallization/dehumidification unit for PET recycling and virgin PET production lines.
    • Applicable Materials: Crystallized PET bottle flakes, recycled PET pellets, low-IV virgin PET resin (initial IV typically 0.60–0.72 dL/g); must be pre-crystallized and dried to ≤50 ppm moisture.
    • Core Processes: Material feeding → pre-heating → solid-state polymerization (nitrogen atmosphere, temperature 200–225°C) → nitrogen purification & recycling → cooling → high-IV PET discharge.
    • Core Value: Increases PET IV to 0.78–0.85 dL/g (bottle-grade) or 0.90+ dL/g (fiber/sheet-grade); reduces carboxyl end group (CEG) content; improves thermal stability, mechanical properties and barrier performance; enables recycled PET to meet food-contact and high-end application standards.
    • Applicable Enterprises: PET bottle recycling plants, bottle-grade PET pellet manufacturers, fiber-grade PET producers, PET sheet/film processing enterprises, virgin PET resin factories.

Key Types of SSP System

SOLID STATE POLYMERIZATION SYSTEM

Solid State Polycondensation Plant

Solid State Polycondensation Plant for high-viscosity PET production.

SOLID STATE POLYMERIZATION SYSTEM

SSP System for Bottle-grade PET

SSP system for high-quality bottle-grade PET production.

SOLID STATE POLYMERIZATION SYSTEM

Polyester Chip Tumble Dryer SSP system

Polyester chip tumble dryer for SSP pre-drying.

Core Product Portfolio & Application Scenarios

Solid State Polycondensation Plant

A Solid State Polycondensation (SSP) Plant is designed to increase the intrinsic viscosity and molecular weight of amorphous PET chips through controlled thermal treatment in an inert (typically nitrogen) or vacuum environment. The process involves pre-crystallization, drying, and polycondensation at temperatures below the melting point but above the glass transition point, enabling chain extension without melting. Widely used in bottle, film, and industrial fiber manufacturing, SSP plants produce high-quality rPET or virgin PET with enhanced mechanical and thermal properties, meeting stringent food-grade or engineering-grade standards.

SSP System for Bottle-grade PET

The ML180 Cutter Compactor is a compact, high-efficiency granulator designed for processing PP, PE, and LDPE plastic films—such as shopping bags, shrink wrap, and packaging scraps. It combines cutting and densification in one step, turning lightweight, bulky film into dense, free-flowing flakes ideal for direct feeding into extruders or washing lines. Featuring robust blades, low noise operation, and a capacity of 100–150 kg/h, the ML180 offers reliable pre-processing for small to medium-scale recycling operations.

Polyester Chip Tumble Dryer SSP system

The Polyester Chip Tumble Dryer is a critical component in the Solid State Polycondensation (SSP) system, designed to thoroughly dry polyester (PET) chips before crystallization and polycondensation. Using heated, dehumidified air in a rotating drum, it ensures uniform moisture removal—typically reducing water content to below 50 ppm—without causing particle agglomeration or thermal degradation. This pre-drying step is essential for stable SSP performance, as residual moisture can hydrolyze PET chains during high-temperature processing. The tumble dryer’s gentle agitation, corrosion-resistant construction, and precise temperature control make it ideal for both virgin and recycled bottle-grade PET chip preparation.

Complete Process Flow & Equipment Configuration

Disassembly of the entire production process and detailed description of each functional module
PET SSP System Sub-module Specifications
Sub-module Name Core Composition Core Functions
Feeding & Metering Module Screw feeder with frequency conversion, anti-bridging hopper, material level sensor Uniform and continuous feeding of pre-dried PET materials; precise metering to match reactor load
Gradient Pre-Heating Module Insulated pre-heater, multi-point temperature sensors, nitrogen pre-heating unit Gradually heats PET to the SSP reaction temperature range (200–225°C); avoids thermal shock to materials
SSP Reactor Module Vertical/tubular reactor, multi-zone heating jacket, residence time adjustment mechanism Core reaction unit; provides stable temperature and inert atmosphere for PET solid-state polycondensation
Nitrogen Purification & Recycling Module Oligomer filter, molecular sieve moisture absorber, nitrogen compressor, purity sensor Purifies nitrogen containing oligomers and moisture; recycles nitrogen to ensure inert atmosphere stability and reduce consumption
Gradient Cooling Module Water-cooled cooler, air-cooled buffer section, closed-loop conveyor Gradually cools high-IV PET to ≤50°C (safe handling temperature); prevents material agglomeration
Central Control Module PLC controller, HMI touch screen, safety interlock system, data logging unit Integrates control of all modules; real-time monitoring of key parameters (temperature, pressure, IV, nitrogen purity); automatic fault alarm and data traceability

Core Advantages & Technical Highlights

Precise IV Control

Multi-zone temperature regulation, 4–10h adjustable residence time, online IV monitoring; control accuracy ±0.02 dL/g.

Low-Consumption Nitrogen System

Closed-loop circulation, purity ≥99.99%, oxygen <50 ppm; cuts nitrogen usage by 35%, avoids PET oxidation.

Energy-Saving Design

Waste heat recovery, frequency-conversion blowers; unit energy consumption ≤1.2 kWh/kg, 20% lower than conventional models.

Eco-Friendly Compliance

No VOC/wastewater discharge; recyclable oligomer by-products; meets EU REACH & US FDA standards.

Intelligent Operation

High-speed centrifugal dewatering removes ~90% surface moisture, followed by hot-air drying to ≤0.5% moisture—ideal for direct pelletizing or storage without mold risk.

Stable Quality Output

Uniform molecular weight distribution; low product performance fluctuation; qualification rate ≥99%.

Technical Parameters

Quantitative presentation of key technical indicators of the equipment
PET SSP System Technical Indicators
Technical Indicator Specification Range Description
Processing Capacity 50–3000 kg/h Customizable according to production scale; supports modular expansion
SSP Reaction Temperature 200–225°C (adjustable) Below PET melting point; avoids material melting
Residence Time 4–10 hours (adjustable) Longer time for higher target IV; precise control via material conveying speed
Initial IV of Input Material 0.60–0.72 dL/g Standard input range for recycled/virgin low-IV PET
Target IV of Finished Product 0.78–0.85 dL/g (bottle-grade); ≥0.90 dL/g (fiber-grade) Meets industry standards for different high-end applications
Nitrogen Purity ≥99.99% Ensures inert atmosphere; prevents PET oxidation
Oxygen Content in Reactor <50 ppm Controlled by closed-loop nitrogen system
Unit Energy Consumption ≤1.2 kWh/kg (finished product) Based on heat recovery system; varies with processing capacity
Overall Dimensions (Standard Model) 6.5m×3.2m×5.5m (L×W×H) Industrial standard footprint; customizable for workshop layout
Power Supply 380V/3Ph/50Hz Compatible with global industrial power grids (customizable to 415V/60Hz)
Certifications CE, ISO 9001, SGS, FDA (food-contact compliant) Complies with international safety, quality and food contact standards

Value Advantages for Customers

Boosts Product Value

Upgrades low-IV PET to bottle/fiber grade; increases added value by 30–50%.

Cuts Production Costs

35% less nitrogen consumption; 20% lower energy costs; 40% reduced labor input.

Stabilizes Quality

Precise IV control; ≤1% scrap rate; consistent performance for high-end applications.

Long Service Life

Alloy core components; 12+ years lifespan; low maintenance frequency.

One-Stop Support

Pre-sales planning, on-site commissioning, 24h technical service; global logistics support.

Broadens Application Scope

Enables recycled PET to meet food-contact standards; accesses high-end textile/packaging markets.

Frequently Asked Questions

Key factors include reaction temperature, residence time, nitrogen purity, and initial moisture content of PET materials. Our system achieves precise control of these parameters through intelligent algorithms to ensure stable IV upgrading.
Yes. However, it is recommended to separate colored and transparent PET for processing to avoid color cross-contamination. The system’s low-oxygen atmosphere can effectively prevent color deepening during polymerization.
Regular maintenance includes: replacing nitrogen purification filters every 6 months, replacing desiccants every 12 months, inspecting reactor insulation performance annually, and calibrating online IV sensors every 3 months.
Yes. The feeding and discharge interfaces can be customized according to the parameters of existing crystallization, drying, and pelletizing equipment, realizing seamless connection and continuous production.
Standard models: 40–50 working days; customized models: 50–60 working days. We support flexible payment terms such as T/T and L/C, and accept small-batch trial orders to help customers verify performance.