General:

Pre-expansion can be carried out batch wise or continuously. Both the sealed batch pre-expanders and the vented continuous pre-expanders are generally in the form of upright cylinders, but a few designs are based on horizontal or inclined forms.

Batch pre-expanders:

The vessel is charged with an appropriate mass of fresh EPS beads and purged with steam to remove most of the air. While the beads are agitated by a stirrer, further steam is admitted until the pressure reaches the desired value. Since the level of the material in the vessel rises as the beads expand, the beads can be discharged shortly after the required degree of expansion.

Continuous Pre-Expander:

EPS beads are introduced continuously at the bottom and expanded beads leave at top. As in a batch pre-expander, the beads are agitated by a stirrer. Steam is supplied steadily at a fixed rate; the inlet excess pressure is kept as low as possible. The expanded beads leave the vessel through an opening at a constant height and their residence time is adjusted by varying the feed rate

Specifications:

Features:

• Rugged construction for continuous operation without maintenance.
• Automatic shut down and start up system that assures no lumps.
• Feed system allows high flexibility on flows for high and low densities, using an adjustable frequency drive.
• Inside view with glasses at two levels.
• Doors allow access to pre-expander inside for lumps removal if needed.
• The agitator shaft can be removed and the feed screw can be dismantled for cleaning.
• PLC control can be connected to an automated silos control operation

Commonly used terms industry terms (Proprietary & Non-Proprietary): EPS, Expanded Polystyrene, Expandable Polystyrene, Styrofoam, Thermocole, Thermocol, Styropor, Foam, Packing Foam, Packaging, Aluminium Molds, Aluminum Molds, Aluminium Moulds, Aluminum Moulds, Shape Moulding Machine, Shape Molding Machine, Mould, Mold, ICF, Insulated Concrete Forms.