The plastic sheeting and stretch film business is not Greek to Sigma Plastics. Growing through acquisitions, the conglomerate (one of the industry's largest in North America) produces plastic film and sheet for primarily industrial, institutional, and government markets. Subsidiary Alpha Industries and its 15 sister subsidiaries, including Beta, Epsilon, and Omega, make plastic film and bags for dry cleaners, grocers, and retailers, as well as foodservice, health care, janitorial, industrial packaging, lodging, and safety industries. Sigma Plastics manufactures its myriad polyethylene film products on 450-plus extrusion lines, operating at 35 plants dotting North America. Chairman Alfred Teo owns the company.