Patent ID: 7935301

Claim:
A method of thermoforming comprising the steps of: (1) providing a film comprising: (i) a skin layer forming an outer surface of the film, wherein: the skin layer has a melting point of at least about 130° C. and at most about 150° C.; and the skin layer comprises one or more propylene/ethylene copolymers; and (ii) a first polyamide layer forming an interior layer of the film, wherein: the first polyamide layer has a melting point of at least about 125° C. and at most about 230° C.; and the first polyamide layer comprises one or more polyamides; (iii) an intermediate layer between the skin layer and the first polyamide layer, wherein: the intermediate layer has a melting point of at least about 105° C. and at most about 150° C.; and the intermediate layer comprises one or more propylene/ethylene copolymers; (iv) a sealant layer forming an outer layer of the film, wherein the sealant layer has a melting point of at most about 130° C.; (v) a barrier layer comprising ethylene/vinyl alcohol copolymer, wherein the barrier layer is directly adjacent the first polyamide layer; (vi) a second polyamide layer directly adjacent the barrier layer and comprising one or more polyamides; and (vii) a tie layer between the intermediate layer and the first polyamide layer, the tie layer comprising one or more tie polymers; (2) heating the film; and (3) thermoforming the heated film onto a mold having a mold depth of at least about 2 inches.