Raw materials + masterbatch → Mixing → Vacuum feeding → Raw material drying → Single-screw extruder → Color line extruder → Spiral die → Sizing sleeve → Spray vacuum shaping box → Spray cooling water tank → Inkjet printer → Tracked traction machine → Finished product inspection and packaging
Industrial Production Process
Traditionally, three manufacturing processes are most representative of polypropylene production.
1. Hydrocarbon slurry or suspension: A liquid inert hydrocarbon diluent is used in the reactor to transfer propylene to the catalyst, remove heat from the system, deactivate/remove the catalyst, and dissolve the atactic polymer. The range of grades that can be produced is very limited. (This technology is no longer used).
2. Bulk (or large-volume slurry): Liquid propylene is used instead of a liquid inert hydrocarbon diluent. The polymer is insoluble in the diluent and rides on the liquid propylene. The resulting polymer is withdrawn, and any unreacted monomers are flashed away.
3. Gas phase: Gaseous propylene is used in contact with a solid catalyst, resulting in a fluidized bed medium.
