Historically and presently, almost all screen printing is done with plastisol, a complex mixture of vinyl resin, a plasticizer and one or more pigments. Fusion or "setting" of freshly printed plastisol into a dried film requires exposure of the screen printed fabric to temperatures exceeding 300.degree. F. This increases the cost of the screen printed product and consumes precious energy.
Moreover, dried plastisols are not biodegradable and some of the components used in conventional screen printing are hazardous. Screen printing generates waste it which often contains hazardous materials, creating disposal problems.
The screen printing industry, seeking ways to reduce printing costs and faced with governmental regulations aimed at conserving energy and reducing environmental pollution, has been investigating alternative methods and materials to reduce or eliminate the foregoing problems. See "Industry Dyeing to be `Green`" on pp. 24-25, Imprinting Business issue of August 1993, and Environmental Protection Agency hazardous waste circular "Printing and Allied Industries" published Apr. 15, 1990.
USPTO Backgrounds
USPTO Backgrounds