Method for producing an acoustic shield for covering an automobile engine

摘要

The method comprises providing a side glass felt layer (3) incorporating a thermo hardening resin, where the side layer shows a relative stress-strain characteristic in compression to be lower than 0.3 kPa, providing a back polyurethane foam layer (4) with a density of 8-15 g/l and a relative stress-strain characteristic in compression to be 3-25 kPa, hot compressing the felt layer and the polyurethane foam layer stacked one upon the other in a mold. The backing layer has an air resistance of lower than 5000 N.s.m 3>. The method comprises providing a side glass felt layer (3) incorporating a thermo hardening resin, where the side layer has a relative stress-strain characteristic in compression to be lower than 0.3 kPa, providing a back polyurethane foam layer (4) with a density of 8-15 g/l and a relative stress-strain characteristic in compression to be 3-25 kPa, hot compressing the felt layer and the polyurethane foam layer stacked one upon the other in a mold. The backing layer has an air resistance of lower than 5000 N.s.m 3>. The method further comprises: arranging a side coating layer (5) provided with a porous thermosetting adhesive on the felt layer before hot compression; and arranging a back coating layer (6) provided with a porous thermosetting adhesive on the foam layer before hot compression. An independent claim is included for an acoustic shield.