Providing an effective way to make peelable lids for retortable polypropylene (PP) packages, DuPont Appeel 22D843 lidding sealant resin is pellet-blended with a polypropylene sealant resin and then processed to make a lidding structure or sealant layer in conventional extrusion or coextrusion equipment designed for polyolefin resins. Typically blended with PP at addition rates of 20 to 40% by weight, the proportion of the resin in the blend determines peel strength; lower addition rates result in higher peel force and vice versa. Blends of the resin and PP can withstand sterilization conditions from 121°C for 20 minutes up to 134°C for 6 minutes with adequate counterpressure, depending on the type of PP employed.

DuPont Packaging & Industrial Polymers; 302-996-7911; www.dupont.com