DUPONT UPS NYLON PRICE: DuPont said late last week it planned to raise its prices on selected fine-denier nylon yarns for hosiery, beginning June 1. The Wilmington, Del., fiber giant said the increasing cost of raw materials — driven by rising oil prices — made the price increase necessary. The company added that it last increased its prices on fine-denier nylon in 1991.

MATERIAL TALKS: The organizers of the upcoming Material World textile trade show said Philadelphia University officials were planning a series of seminars to be presented at the show. The seminars will tackle fibers, computer-assisted design, trade issues and fashion, in English and Spanish. Material World is produced by Fairchild Urban Expositions, based in Atlanta, a partnership of Fairchild Publications Inc., which publishes WWD, and Urban Expositions & Development. The show is to make its debut Sept. 25-27 at the Miami Beach Convention Center in Miami.

MACK TO SAXON: New York converter Saxon Textile Corp. has named Ronnie Mack vice president. Mack, an 18-year veteran of Majestic Mills, where he was vice president of marketing, reports to Gail Strickler, Saxon President