The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 22, 2008
Filed:
Jul. 01, 2004
Delton R. Thompson, Jr., Woodbury, MN (US);
Xiaohe Liu, Woodbury, MN (US);
Delton R. Thompson, Jr., Woodbury, MN (US);
Xiaohe Liu, Woodbury, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
A sound absorptive multilayer composite having an air-impermeable barrier, an air-permeable reinforcing core having an airflow resistance of at least about 100 mks Rayls and a thickness at least about ⅓ the final composite thickness, an air-permeable open cell foam or fibrous pad having an airflow resistance less than about 2000 mks Rayls and a thickness at least about 1/10 the final composite thickness and a semipermeable airflow-resistive membrane having an airflow resistance of about 500 to about 4000 mks Rayls can provide improved acoustic performance. For example, existing vehicular headliner designs may be improved by adding a properly chosen and properly positioned semipermeable airflow-resistive membrane, a properly chosen and properly positioned air-impermeable barrier, or a properly chosen and properly positioned open cell foam layer.