Unipol process (vapor-phase polymerization) developed by UCC

Reaction by direct contact of vapor-phase PL and the solid catalyst

Wide distribution of molecular weights of products

Regulation of molecular weight distribution through cracking

Low operation cost due to low utility consumption

Difficult to operate due to numerous property-regulating variables such as temperature, pressure, and composition

Adoption of fluidized bed reactor in PP polymerization process

Simple handling of solids and easy discharge of fluidized solids through reactor nozzle

Quick mixing as solid particles are in continuous movement

Excellent heat and mass transfer between vapor and solid with heat easily transferred through moving solid  particles (ease of temperature control)

Step1

The powder PP produced by the reactor is passed through the degassing & purge step to be fed to the granulation process and mixed with additives to be melted, cut, and solidified to produce the pellet form.

Step2

The pelleting process includes the mixing and extrusion function where the fed resin and additives are mixed and melted.

Step3

- The additives and feed resin are injected into the continuous mixer (LMC). The melt pump speed is regulated according to the mixer discharge pressure.
- The resin pressurized by the melt pump is cleared of foreign substances in the screen pack and fed into the die plate channel
- The molten resin is injected through the die plate heated by steam and pelletized under water by a rotary knife.

Final step

- The water is dehydrated and recovered into the PCW tank for regeneration.
- The pellets are dried in the centrifugal drier and transported to the product bin