Plastic market bag

Claim 2

A bag formed from a seamless section of film tubing comprising in its open condition: a major length portion of generally rectangular cross section formed by four spaced apart folds running lengthwise along the film section defining two pairs of opposing wall members therebetween; and a bottom portion formed by inwardly folded extensions of said wall pair members, the extensions of one pair of said wall members being joined at a seam intermediate the bottom portion, the other pair of wall member extensions being folded back to provide a gusset section at each of the corner ends thereof which overlie and are joined to respective corner ends of the extension of said one pair of wall members, the marginal edges of adjacent wall membrs at each of said lengthwise folds being sealed together to define respective lengthwise seams at each of said folds, the seam intermediate the bottom of said bag being provided by a heat seal joining the folded extensions of said one pair of wall members and each of said gussets being heat sealed to the respective bottom corners of said one pair of wall members and merging with said intermediate seam.

Claim 3

A market bag which stores flat in closed condition and when opened is flat bottomed and self standing, comprising: a length of seamless tubular plastic film having top and bottom edges and four axial folds formed therein to provide two pair of opposing wall members; two axial fold lines located substantially midway along the respective wall members of one of said two pairs of opposing wall members; said one pair of wall members being folded inwardly along said respective fold lines to flatten said tubular film and bring said other opposing wall members into uniform registration with each other with said bag in closed condition; a first heat sealed section joining the bottom edges of each of said wall members; second heat sealed triangular sections located at each of the corner portions of the bottom edge of said film, said triangular sections having one edge defined by said first heat sealed section and a second edge defined by each of said axial folds, said two edges in the respective triangles forming a right angle, said triangular sections providing a substantially flat bottomed base for said bag in open condition with said two pair of opposing wall members defining a substantially rectangular cross sectional area therebetween, said four axial folds being each heat treated to provide axial stiffness for said bag such that said wall members are substantially self standing with said bag in open condition; and third heat sealed sections extending respectively along each of said four axial folds and merging into said second sections at the respective corner portions at the bottom of said bag.

Claim 4

A market bag which stores flat in closed condition and when opened is flat bottomed and self standing, comprising: a length of seamless tubular plastic film having top and bottom edges and four axial folds formed therein to provide two pair of opposing wall members; two axial fold lines located substantially midway along the respective wall members of one of said two pairs of opposing wall members; said one pair of wall members being folded inwardly along said respective fold lines to flatten said tubular film and bring said other opposing wall members into uniform registration with each other with said bag in closed condition; a first heat sealed section joining the bottom edges of each of said wall members; second heat sealed triangular sections located at each of the corner portions of the bottom edge of said film, said triangular sections having one edge defined by said first heat sealed section and a second edge defined by each of said axial folds, said two edges in the respective triangles forming a right angle, said triangular sections providing a substantially flat bottomed base for said bag in open condition with said two pair of opposing wall members defining a substantially rectangular cross sectional area therebetween, said four axial folds being each heat treated to provide axial stiffness for said bag such that said wall members are substantially self standing with said bag in open condition; and third heat sealed sections extending respectively along each of said four axial folds and merging into said second sections at the respective corner portions at the bottom of said bag.