Process for forming a peelable seal
AssigneePharmachem Corporation
InventorWilliam E. R. Watt
Life of this patent
Estimating the term…
Abstract
A process for forming a peelable seal by heat sealing under combined application of heat and pressure at least two polyolefin film members having at least one oxidized surface therebetween, and the seal formed thereby.
Claims7
In a process for forming a peelable seal with at least two extruded polyolefin film members by the simultaneous application of controlled heat and pressure to said film members at the portion to be sealed, the improvement which comprises oxidizing by corona discharge treatment at least one surface of at least one of the polyolefin film members at the portion to be sealed so as to modify by oxidation the structure of the surface crystals formed by extrusion and then simultaneously applying controlled heat and pressure to soften the modified crystals at the contacting surface to partially fuse the crystals at the contacting surface while maintaining the integrity of the crystals so that the modified crystals form an interface between the polyolefin film members at the seal portion and a peelable seal is thereby formed.
Dependencies are inferred from the claim text.