Membrane sealed carton

Claim 2

An end sealed carton fabricated from a thermoplastic coated sheet material including a paperboard layer and a barrier layer, said carton comprising: a. a carton body having consecutively articulated first side, front wall, second side and rear wall panels; b. flaps articulated to the ends of each of said wall panels along hinge lines; c. a sealing membrane having parallel side edges; d. means strongly bonding said membrane to the inner surfaces of all of said flaps to close off the ends of said carton; e. a line of weakness formed in each of a pair of said flaps at one end of the carton body proximate to said hinge lines and generally coincident with said parallel side edges of the membrane; f. the lines of weakness with said hinge lines thereby delineating the edges of narrow delamination zones in the inner stratum of the paperboard of said flaps; and g. at least one of the remaining flaps at said one end of the carton being freely severable from said carton body along its hinge line.

Claim 3

The carton of claim 1, in which: a. the lines of weakness are formed by a series of check-shaped cuts impressed through the blank from the outer side thereof.

Claim 4

The carton of claim 1, in which: a. the flaps having said lines of weakness are adhered and the portions lying between said lines of weakness constitute a readily removable compound tear strip.

Claim 5

The carton of claim 1, in which: a. one of the pairs of flaps having said lines of weakness therein further includes a tab portion at its free edge while the other flap of said pair further includes a mating slot portion.

Claim 6

The carton of claim 1, in which: a. said freely severable flap is articulated to said carton body by cuts impressed partially, but not completely, through the sheet material.

Claim 7

The carton of claim 1, in which: a. said front and rear walls are wider than said sidewalls; b. said lines of weakness are formed in the flaps articulated to said front and rear walls.

Claim 8

A one-piece paperboard blank for an end-fillable carton adapted to be end sealed with a membrane of predetermined width, comprising: a. first sidewall, front wall, second sidewall, rear wall, and glue flap panels consecutively articulated along parallel vertical score lines; b. dust flaps articulated to the ends of said sidewall panels along horizontal fold lines, at least one of said dust flaps is articulated to a sidewall panel along a line of severance; c. end flaps articulated to the ends of said front and rear wall panels along horizontal score lines; d. delaminable narrow strata of paperboard formed in said end flaps and bounded by said horizontal score lines and lines of weakness parallel thereto; e. said lines of weakness being defined by a series of cuts and being arranged to be mutually spaced a distance substantially equal to said predetermined width of the membrane sealing material when said blank is formed into a parallelepiped carton tube and said end flaps are outfolded into a horizontal plane, whereby said delaminable strata may be readily separated from the remainder of said carton tube along with said membrane.

Claim 9

A one-piece paperboard blank for an end-fillable carton adapted to be end sealed with a membrane of predetermined width, comprising: a. first sidewall, front wall, second sidewall, rear wall, and glue flap panels consecutively articulated along parallel vertical score lines; b. dust flaps articulated to the ends of said sidewall panels along horizontal fold lines, at least one of said dust flaps is articulated to a sidewall panel along a line of severance; c. end flaps articulated to the ends of said front and rear wall panels along horizontal score lines; d. delaminable narrow strata of paperboard formed in said end flaps and bounded by said horizontal score lines and lines of weakness parallel thereto; e. said lines of weakness being defined by a series of cuts and being arranged to be mutually spaced a distance substantially equal to said predetermined width of the membrane sealing material when said blank is formed into a parallelepiped carton tube and said end flaps are outfolded into a horizontal plane, whereby said delaminable strata may be readily separated from the remainder of said carton tube along with said membrane.

Claim 10

The blank of claim 7, further characterized in that: a. said cuts are check-shaped.