By Liz White, UT editor
Verano Brianza, Italy-Italian supplier of polyurethane machinery Impianti OMS, has developed a special dedicated unit capable of mixing and metering correctly a blend of solid and liquid (slurry). This slurry is then injected, as an additional component, into the different polyurethane technological processes related to insulating panels production.
OMS points out that use of solid components, in particular mineral fillers, in polyurethane systems to make insulating sandwich panels, is a well-known technique. It can give the final product better physical-mechanical properties or can be used to improve the fire behaviour.
And OMS adds that, "another solid component of great interest is polyurethane powder obtained from scrap or defective production pieces by mechanical recycling."
Use of such recycled PU brings many environmental advantages and also economic benefits, the Italian group added.
The metering unit, called EcoFiller, has a machine day-tank for solid + liquid blending and to avoid sedimentation, with a metering pump group especially designed for use with highly abrasive fillers, according to Verano Brianza, Milan-based OMS.
For final mixing of this blend with polyol blend and isocyanate, OMS said, it has produced a set of high-pressure self-cleaning mixing heads that allow an additional feeding nozzle as a third, separate, stream.
By pairing an "EcoFiller" unit with suitable mixing heads, the system can be incorporated into a continuous or discontinuous process to make sandwich panels.
An EcoFiller unit is available in the group's R&D department, for customer trials in discontinuous process and at the customer's site in a continuous process, OMS said. "