Particle Foam Machine Division - KURTZ GmbH - #5

Pre-Expansion Process Flow

EPS is pre-expanded as expandable beads are fed into the pre-expander. Hot watervapour as a medium first sof­tens the polystyrene beads, and the blowing agent thus released in them is activated. Pre-expansion involves vaporization and thus the swelling of the beads.

During intermediate storage the propellant gas is diffused from the expanded styrene granules and air penetrates. This "packed air" is further processed in a shape mould­ing machine or block mould .

EPS may also be subject to a second expansion process to achieve lower particle densities. Expandable poly­propylene (EPP) is expanded to low densities using so called HP pre-expanders.

re-expansion chamberwith discharge

V800 continuous pre-expander

Screening unit with cellularwheel sluice

^ Continuous pre-expanders for block and shape moulding

^ Batch pre-expanders for block and shape moulding

i Laboratory pre-expanders for research and development