Peelable film laminate
AssigneeR. J. Reynolds Tobacco Company
InventorDennis L. Carespodi
Life of this patent
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Abstract
The invention provides a packaging laminate which is heat sealable to polypropylene, high density polyethylene or linear low density polyethylene to provide a strong seal which is cleanly peelable at the heat seal interface under hand pressure. The laminate has at least two layers. A heat sealable surface layer is composed of a melt blend comprising between about 55 and 95 wt. % of a substantially linear polyolefin and between about 5 and about 45 wt. % of a polyolefin rubber. The second layer is a heat stable layer which is structurally stable at temperatures in excess of 350.degree. F. or greater and which has sufficient thickness to provide structural stability during heat sealing.
Claims14
A heat sealable packaging laminate closure member for a container having a closure surface selected from the group consisting of polypropylene, high density polyethylene or linear low density polyethylene, said closure member being capable of forming a strong, cleanly peelable heat seal with said container, said closure member comprising:
- (a) a thermoplastic heat sealable surface layer composed of a melt blend comprising between about 55 and about 95 wt. % of a substantially linear polyolefin and between about 5 and about 45 wt. % of a polyolefin thermoplastic elastomer;
- and
- (b) a heat stable second layer which is structurally stable during heat sealing at temperatures of about 350.degree. F. or greater and having sufficient thickness to provide structural stability during heat sealing.
A sealed package comprising a pair of members peelably sealed to each other wherein the contacting surface of the first member consists essentially of polypropylene, high density polyethylene or linear low density polyethylene, and wherein the contacting surface of the second member is composed of a thermoplastic heat-sealable polymer which is a melt blend comprising between about 55 and about 95 wt.% of a substantially linear polyolefin together with about 5 to about 45 wt.% of a polyolefin thermoplastic elastomer and wherein the seal between the first member and the second member is cleanly peelable at the heat seal interface, under hand pressure, and maintains strength at temperatures of about 180.degree. F.
Dependencies are inferred from the claim text.