Electret webs with charge-enhancing additives Grant US-8613795-B2 United States of America 24 Dec 2013
Electret webs with charge-enhancing additives Grant US-8529671-B2 United States of America 10 Sep 2013
Method of making electret articles based on zeta potential Grant US-7765698-B2 United States of America 03 Aug 2010