Item 8.01. Other Events.

On February 25, 2013, Polypore International, Inc. (the "Company") announced that Celgard, LLC ("Celgard"), a subsidiary of the Company, filed a complaint in the U.S. District Court of the Western District of North Carolina against Sumitomo Chemical Company, Limited. The complaint alleges that Sumitomo Chemical has infringed Celgard's United States Patent No. 6,432,586 issued for an invention entitled, "Separator for a High Energy Rechargeable Lithium Battery." The patent in the lawsuit covers ceramic composite layer lithium-ion battery separators first developed by Celgard for high-energy rechargeable lithium-ion batteries. This lawsuit has been filed after a period in which Celgard attempted to resolve its concerns with Sumitomo Chemical over infringement of Celgard's patent.

A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No. Description

99.1 Press Release of Polypore International, Inc., dated February 25, 2013

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