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 Inventors Russell J. Williams
Sun City, Ariz.;
Milton J. Heimos, Affton, Mo.
 Appl.No. 729,122
 Filed May 14,1968
Division of Ser. No. 597,169, Nov. 25,1966, Pat. No. 3,394,871, which is a continuation of Ser. No. 340,995, Jan. 29,1964.
 Patented Mar. 16,1971
 Assignee Bemis Company, Inc.
 METHODS OF MANUFACTURING PLASTIC BAGS 12 Claims, 23 Drawing Figs.
 U.S.CI 93/35,
 IntCl B31b 49/04
 Field of Search 93/8,35;
260/(Ink Digest); 156/289,290; 229/51 (WB),
 References Cited
UNITED STATES PATENTS 3,217,871 11/1965 Lee 229/51X
3,237,534 3/1966 Lissner 93/8X
3,319,868 5/1967 Huangetal 229/51X
225,010 3/1959 Australia 229/51WB
Primary Examiner— Bernard Stickney
Attorney—Koenig, Senniger, Powers and Leavitt
ABSTRACT: A method of manufacturing plastic bags with a plastic tape folded around one end of the bag and heat-sealed to the bag walls with heat-seal-inhibiting material precluding sealing together of the walls where the tape is sealed to the walls. A method of manufacturing plastic bags with a heatsealed pinch-type closure with heat-seal-inhibiting material precluding sealing together of the walls where the closure is sealed. A method of manufacturing plastic bags with an interrupted or vented heat-sealed longitudinal seam with heat-sealinhibiting material in a pattern for forming the interrupted or vented longitudinal seam. A method of manufacturing plastic bags with a valve sleeve sealed in a heat-sealed longitudinal seam with heat-seal-inhibiting material on the inside of the sleeve to preclude sealing together of the walls of the sleeve.