New Processes Allow Short Throughput Times
Infrared Based Pre-Foaming Is Heading for Series Maturity
Steamless pre-foaming of bead foams has been the aim of a research project called "IR-PreFoam". The project team has succeeded in elucidating the underlying pro-cess-structure-property relationships. This crucial knowledge represents the basis for a successful scaling and industrialization of a novel energy-efficient processing tech-nology for expandable polymeric beads.
Dry Process for Pre-Foaming
Nowadays, microgranules loaded with foaming agents are firstly expanded into foam beads, which can subsequently be fused together to form molded parts. Using state of the art technology, both sub-processes are based on steam as energy source, which requires a comparatively complex infrastructure and high input of resources.
A novel, completely dry process for pre-foaming (currently patent pending), devel-oped by FOX Velution GmbH in Lichtenfels, Germany, is based on medium wave infrared radiation. This enables continuous processing at very short cycle time and furthermore eliminates the need for bead drying. In addition, the new technology is not only suitable for the globally spread expandable polystyrene (EPS), but also for the refinement of any expandable bead foam, even for high performance polymers.
The project consortium – consisting of FOX Velution GmbH and Rygol Dämmstoffe GmbH, Painten, Germany, as industrial partners and Neue Materialien Bayreuth GmbH (NMB) as research institute – have investigated the relationship between the effects of radiation and the resulting material properties. Now, cell morphology and bulk density of the foam beads can be precisely and reproducibly adjusted over a wide range to meet the specific requirements of various applications.
Another focus has been drawn on the scalability of the process and the correspond-ing plant technology covering initial laboratory equipment through pilot plant scale up to industrial serial production. This has created essential prerequisites for market introduction of this promising technology.
The project was funded by the Bavarian State Ministry of Economic Affairs, Regional Development and Energy within the project framework of "Neue Werkstoffe in Bayern" (new materials in Bavaria).