His development of creped wadding, a soft and fluffy absorbent material, became over time one of Kimberley-Clark's most important products and the source of billions of dollars in global sales.

During World War I, creped wadding made from paper had been developed as a cotton substitute for surgical dressings; under Mahler's commercialization process, it became the basis of such well-known products as Kleenex and Kotex.

[1] The US Army Service Forces appointed Mahler to their purchase policy division during World War II.

After the war, he spent further time as a consultant for the reconstitution of papermaking industries in Belgium, Holland, France and Germany.

[1] Mahler served on the board of directors of the Neenah West National Bank,[5] and was an active town resident and civic leader.

Prior to his death, he and his wife arranged to donate over 26 acres of their private property to the municipality for community recreational purposes.