Abstract
Solvent extractions were conducted on 4-foil-laminated materials with films of Lexan-polycarbonate, Rilsan-Nylon 11, Kodar-polyester, and Teflon- fluorocarbon. The film residues extracted were principally laminating adhesives which migrate through or permeate the films. An exception was Lexan- polycarbonate which showed traces of film degradation. All films studied appeared to have excellent thermal stability at temperatures up to 275F. No significant volatile extractives were evident. Extraction yields of the four films tested were all less than maximums specified in Federal Regulations even at extraction conditions in excess of regulation procedures. Procedures were developed using free fats as simulated solvents. Results gave 90-100% recovery of film residues. The development of the above procedure enabled the assessment of existing FDA regulations regarding film extractives at high temperatures (250F and higher). The Federal Regulations imply that film extractions with heptane at 150F for 2 hours result in amounts of residue five times larger than with a food product. From results obtained, it appears that the ratio of heptane extractables at 150F to fat extractables at 275F varies from one film material to another and is not fixed.