Munich, Germany - A polyurethane spraying process being used by German automotive components supplier Duramotive Bayern GmbH to produce "acoustic carpet elements" for cars and trucks can cut the costs of soundproofing.
In this process, developed by machinery supplier KraussMaffei, a soundproofing polyurethane layer is sprayed onto preformed carpet elements in an open mould using a special spray mixing head which, according to KraussMaffei, reduces material consumption, is flexible, and has lower mould costs.
The spray application allows the mixing head to be pointed in any direction at any range of speeds, allowing greater flexibility and control over which areas need soundproofing, the company said, in a 24 Nov statement.
The polyurethane layer has a high barium sulphate content, which is metered using piston metering in the polyol/barium sulphate mix. KraussMaffei's Tandem Hybrid metering machine feeds the abrasive component by means of "two pistons moving anticyclically to deliver steady material flow," the company said.
KraussMaffei also said the mixing head is designed for 'T' mixing, meaning that the polyol component is discharged into the mixing chamber through the two nozzles opposite each other. The jet of isocyanate hits the stream at right angles, achieving excellent mixing quality. This allows for a wider processing window and less stress on the material, according to the Munich, Germany-based group.