Frank J. Mann, 81, founder and retired board chairman of the Mann Potato Chip Co. of Washington, died Monday in Boca Raton, Fla., where he had resided for the last two years.

He had founded the Mann firm in 1932. A family-owned business, the company and its subsidiaries had become the largest potato chip and snack maker in the Middle Atlantic states by 1957, when it was acquired by Sunshine Biscuits, Inc.

It continued to retain its identity with Mr. Mann as chairman of the board and his son, Frank E., as president. His wife, Louise, had been serving as vice president, and his daughter, Louise Mann Madden, as secretary

In 1962, Sunshine Biscuits, of which the Mann Co. was a division, elected Mr. Mann as a vice president. He retired from both his positions about 10 years ago.

Born in Calvert, Tex., Mr. Mann came to Washington during World War I, when he served with the U.S. Army. He remained here after the war and held a variety of jobs before founding the potato chip company.

He was made a director of the National Capitol Bank of Washington in 1947 and served on its executive board for a number of years.

Mr. Mann was active in many philanthropic and civil organizations. They included the Paul Anderson youth Homes for wayward boys in Georgia and Texas, the Frank Jelleff Branch of the Boys' Clubs of Greater Washington and the National Capitol Optimist Club.

A 32d degree Mason, he was a life member of Almas Temple and belonged to the Jesters. He also was a member of the Columbia and Congressional Country Clubs.

Survivors include his wife, of the home in Boca Raton; his son, who is mayor of Alexandria; his daughter, of Washington; a brother, Alonzo, of Atlanta, Ga., four grandchildren and two great-grandchildren.