Solid State Polymerization
Solid State Polymerization SSP
Solid state polymerization (SSP) process refers to the condensation polymerization of chips in solid state to increase molecular weight and improve intrinsic viscosity (IV). The technology can be applied to the production of various bottle grade polyester chips and industrial silk chips.
According to the different process, it can be divided into continuous and intermittent.
The continuous solid phase bonding process has stable quality and little damage, and is suitable for large production.
The batch Solid state polymerization process is flexible in product adjustment and suitable for small batch production. The small polyester chips were sliced by crystallization, drying and tackling technology, or the large polyester slices were sliced by crystallization, drying and tackling technology.
Batch production
Advantages:
the overall investment is small, and the product is adjusted flexibly.
The intermittent solid state bonding process includes:
Drum system: used for chip crystallization, drying and viscosity increasing reaction.
Vacuum system: a byproduct formed by forming vacuum and pumping reaction in the drum.
Heat transfer oil circulation system: used for heating and cooling materials.
Continuous production
Advantages:
stable product quality, uniform crystallization, low dust content and low energy consumption. The unique continuous tackifier is used for tackling polyester chips and PA6 chips. PET polyester chips are produced by pre crystallization, crystallization, drying, preheating and viscosity increasing processes. The crystallinity of the production bottle can be more than 50%, the viscosity can be increased to more than 0.88, and the acetaldehyde content is lower than 1ppm. The viscosity of high strength industrial yarn can be increased to more than 1.
The viscosity of the continuous PA6 thickening equipment can be increased to more than 3.5.
The continuous solid-state polymerization process includes:
Crystallizer: the chip is high and uniform in crystallization degree, which can effectively prevent adhesion. According to process requirements, 1-2 stage crystallization device can be adopted.
Preheater: heat the slice to the solid state polycondensation reaction temperature, at the same time increase the partial viscosity.
Reactor: increase the viscosity of the chips to the target viscosity, and get different products by adjusting the process.
Cooler: cooling the slice to the required temperature.
Conveyor device: can provide a variety of transport forms, slicing to all processes.
Nitrogen purification system: used to purify the circulating nitrogen from the Solid state polymerization system, can effectively remove small molecule compounds impurities.
Electrical control system: used for monitoring and recording data. Advanced software and friendly human-machine interface design make data display clear, intuitive and easy to manipulate.