To produce EPP beads, use a Single Screw extruder for black and white colors, and a Twin Screw for mini pellets with colored tints. The most important thing of mini pallet is additive know-how, dies and precise cutting machine.
Thus, the production process is effected by melting the granulate in an extruder from which 100 thin fibers, so-called “spaghetti”, emerge. They are cooled in a water bath, dried and chopped to the required mini pellets, which can be imagined as tiny short needles.
The Mini Pallet is made by mixing a masterbatch with R-PP as the main ingredient and a special foaming accelerator.
2. EPP Beads Expansion System
These Mini Pellets are then put into a stirred autoclave with a dispersion medium (water), dispersing agent, surfactants and a physical blowing agent (CO2) at an elevated pressure and at a temperature above the melting temperature of PP.
After appropriate processing time has elapsed to let the blowing agent impregnate and saturate the pellets, the pressure is released to expand the pellets. Then the expanded beads are cooled, washed and packed.