PET Fibre to fibre Recycling system

Ready for respinning. The 100% rPET pellets produced by the PolyReTec

FibrePro:IV have it all:

high colour fidelity and the excellent mechanical properties needed for further processing into

ultra-fine, 100% recycled PET fibres with a titer of 2 dtex. Suitable for filament, staple and BCF fibres.

As a result of its efficient cleaning and recovery performance, the new PolyReTec FibrePro:IV is also the first choice for especially challenging input materials such as PET fibres that are heavily contaminated with spin finish and have high levels of moisture.

Unique combination of technologies:

PolyRetec Pelletizing system & IV Uptimiser

This is made possible by combining the pelletizing machine, which has proven itself thousands of times over, with innovative IV Uptimiser technology. While the PolyRetec prepares the material for extrusion using its Preconditioning Unit and Agglomerating system to ensure perfect homogenisation, pre-drying,

removal of volatile components, and subsequent gentle PET melting, the new IV Uptimiser ensures repolymerisation, IV lift and efficiently cleans the fibres of finishing additives.

PET Fibres Pelletizing System

PET Chips Solid State Polymerization Unit (SSP)

tailored to the requirements of the fibre industry

• efficient removal of spin finish and additives

(spinning oils, texturiser oils, etc.)

• optimises and increases intrinsic viscosity (IV value)

to the required level during the melt phase

• repolymerisation

The Solid-State Polycondensation (SSP)of PET (Polyethylene Terephthalate) fibers is a process that increases the molecular weight (intrinsic viscosity, IV value) of PET through a solid-state polycondensation reaction. It is widely used in the production of high-strength industrial fibers, engineering plastics, and other high-performance materials. The following is a detailed analysis of this process:

1. Principle of Solid-State Polycondensation Process Under solid-state conditions (temperature below the melting point of PET, typically 230-250°C), the PET molecular chains are extended through a polycondensation reaction, removing small molecule by-products (such as water and acetaldehyde), thereby increasing its intrinsic viscosity (IV value). Compared to melt polycondensation, SSP can avoid degradation caused by high-temperature melting and is more suitable for producing high-viscosity PET.

2.Process Flow

(1) Pretreatment

Drying: Dry PET flakes (or pellets) to a moisture content of less than 50 ppm to prevent hydrolysis-induced chain scission at high temperatures.- Crystallization: Pre-crystallization at 150-180°C to improve the heat resistance of slices and prevent sticking during subsequent high-temperature processing.

(2) Solid-State Polycondensation

Reaction Conditions: Temperature 230-250°C, inert gas (N₂) or vacuum environment, reaction time 10-24 hours.

Polycondensation Mechanism: Esterification reaction between terminal carboxyl groups (-COOH) and terminal hydroxyl groups (-OH), releasing water molecules; simultaneously, transesterification reactions promote molecular chain growth.
(3) Post-processing

Cooling: Slow cooling under inert gas protection to prevent oxidative degradation.

Storage: Sealed and moisture-proof storage to maintain polymer molecular weight stability.

03 —Main Process

Conveyor belt, Shredder ,agglomerator/ compactor, extruder, Candle-Type High Precision Filtration System ,pelletizing unit, water cooling unit, drying unit, storage silo.

SMART intelligent control:

HMI PLC control: ergonomic touch screen, easy operation, high stability.

Recipe memory

Remote diagnosis and data transmission

High safety protection: to protect personnel safety and equipment safety

Emergency stop protection (equipment stop in emergency situations)

limit switch

Protect the shell

High-speed transmission parts warning reminder (yellow paint, sign)

04 — Technical characteristics