a brand of strong, thin polyester film used in photography, recording tapes, and insulation.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
proper name for a polyester film, 1954, trademarked by E.I. Du Pont de Nemours and Co., Wilmington, Delaware, U.S.A. Like many Du Pont names, it doesn't mean anything, they just liked the sound.
Online Etymology Dictionary, © 2010 Douglas Harper