Stone Plastics Inc., of Cadiz, Ky., is one of the largest plastics thermoforming companies in North America, according to a dollar-based ranking published recently in Plastics News.

Stone Plastics Inc. ranks No. 50 among thermoformers of custom and stock products in the United States, Canada and Mexico, placing it with the leaders in a fast-growing industry segment that includes hundreds of such firms. Thermoforming is a relatively small but increasingly important segment of a plastics product manufacturing industry that in the United States alone generates total shipments valued at well over $100 billion a year. The process involves heating a thermoplastic sheet to a working temperature and then forming it into a finished shape through the application of heat or pressure.

Though thermofomers serve many diverse end markets, most produce either packaging or industrial products. Typical packaging uses include disposable cups, egg cartons, fast-food packaging and blister packages. Industrial uses can range from shower enclosures and truck bedliners to pallets and computer housings.  

This information was compiled as part of the second annual ranking of thermoformers by Plastics News, a weekly newspaper based in Akron, Ohio that reports on the business of the plastics industry. Plastics News is published by Crain Communications, Inc., including Advertising Age, Rubber & Plastics News, Automotive News and Waste News.