EP0117730A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Flat bottom plastic bag and method of manufacture
Assignee: T C Manufacturing Co Inc
•
Filing: 1984-02-23
•
Granted: —
•
Expires: 2004-02-23
Abstract
Abstract A flat bottom plastic film bag includes triangular gusset portions formed by a plurality of parallel heat welds which fuse portions of opposed pleats together and cooperate with a transverse central bottom seam to form a flat bottom bag from a seamed or seamless plastic tube. The longitudinal side and end walls of the bag are provided with heat embossed corrugations which enhance the freestanding characteristics of the bag and a transverse crease is formed along the fold line between the sidewalls of the bag and the bottom wall to enhance the bottom forming characteristics of the bag when it is snapped from a folded position to an opened position. The bag may be made by an improved process wherein a blown film tube is continuously slit sealed into a plurality of tubes which are reinflated, then collapsed to form opposed double pleat folds, followed by corrugation of the side and end walls of the tube, formation of the transverse crease defining the fold line between the bottom and sidewalls and, finally, formation of the gusset welds, the transverse bottom seal and perforation or cutoff to form the individual bags.
Inventors
- 👤 John Emerson Hummel
- 👤 William Emil Baab
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 20:16
CPC Classifications
B; B29; B29C; B29C53/00; B29C53/22; B29C53/24; B29C53/26; B29C53/265; B29C53/02; B29C53/10; B29C53/30; B29C65/00; B29C65/02; B29C65/18; B29C65/22; B29C65/221; B29C65/222; B29C65/223; B29C65/228; B29C65/24; B29C65/30; B29C65/305; B29C65/74; B29C65/743; B29C65/7433; B29C65/745; B29C65/7453; B29C66/00; B29C66/004; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/13; B29C66/135; B29C66/137; B29C66/20; B29C66/21; B29C66/40; B29C66/41; B29C66/43; B29C66/431; B29C66/4312; B29C66/432; B29C66/4322; B29C66/438; B29C66/80; B29C66/81; B29C66/814; B29C66/8141; B29C66/81433; B29C66/81435; B29C66/83; B29C66/832; B29C66/8322; B29C66/834; B29C66/8341; B29C66/83411; B29C66/83413; B29C66/84; B29C66/843; B29C66/8432; B29C67/00; B29C67/0014; B65; B65D; B65D31/00; B65D31/08; B29C2793/00; B29C2793/0027; B29C66/70; B29C66/71; B29L; B29L2023/00; B29L2023/001; B29L2031/00; B29L2031/712; B29L2031/7128; B31; B31B; B31B2155/00; B31B2155/001; B31B2155/0012; B31B2155/003; B31B2160/00; B31B2160/20; B31B70/00; B31B70/008; B31B70/14; B31B70/16; B31B70/18; B31B70/26; B31B70/262; B31B70/266; B31B70/60; B31B70/64; B31B70/644; B31B70/649; Y; Y10; Y10S; Y10S493/00; Y10S493/916; Y10S493/936
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
145 words
A flat bottom bag formed of heat sealable tubular plastic material, said bag having opposed generally parallel sidewalls and opposed generally parallel end walls formed by four spaced apart longitudinal folds, a transverse bottom seam formed by joining said sidewalls along one transverse edge of said bag, and a transverse fold line across each of said sidewalls defining a juncture of said sidewalls with a bottom wall defined by said transverse fold line, opposed triangular gussets formed by a lower portion of said end walls, respectively, joined to said bottom wall and delimited by converging lines which extend from opposed ones of said transverse fold lines to said transverse bottom seam, wherein said gussets include means extending substantially across said gussets perpendicular to said bottom seam and joining said gussets to said bottom wall to form opposed relatively stiff reinforced portions of said bottom wall.
Claim 2
Dependent Claim
145 words
A flat bottom bag formed of heat sealable tubular plastic material, said bag having opposed generally parallel sidewalls and opposed generally parallel end walls formed by four spaced apart longitudinal folds, a transverse bottom seam formed by joining said sidewalls along one transverse edge of said bag, and a transverse fold line across each of said sidewalls defining a juncture of said sidewalls with a bottom wall defined by said transverse fold line, opposed triangular gussets formed by a lower portion of said end walls, respectively, joined to said bottom wall and delimited by converging lines which extend from opposed ones of said transverse fold lines to said transverse bottom seam, wherein said gussets include means extending substantially across said gussets perpendicular to said bottom seam and joining said gussets to said bottom wall to form opposed relatively stiff reinforced portions of said bottom wall.
Claim 3
Dependent Claim
33 words
The flat bottom bag according to Claim 1 wherein: said means joining said gussets to said bottom wall comprise a plurality of heat seal bands extending substantially perpendicular to said transverse bottom seam.
Claim 4
Dependent Claim
42 words
The flat bottom bag according to Claim 2 wherein: said seal bands are formed by pressing said lower portions of said end walls against said portions of said sidewalls defining said bottom wall and heating said pressed portions to form said gussets.
Claim 5
Dependent Claim
153 words
A flat bottom bag formed of heat sealable plastic film, said film being formed into an elongated tube having at least one longitudinal seam, said tube being formed with opposed pairs of inwardly folded pleats defined by a longitudinal center fold between a pair of longitudinal fold lines, said pairs of pleats defining opposed end walls of said bag, said bag including opposed sidewalls formed between pairs of adjacent ones of said longitudinal fold lines, a transverse seam joining opposed ones of said sidewalls to close one end of said bag, opposed triangular gussets formed by portions of said pleats sealed to an adjacent portion of respective ones of said sidewalls, said gussets forming a. portion of a bottom wall of said bag, and said one longitudinal seam extends along one of said walls to stiffen said bag in the open position to maintain said bag freestanding and supported by said bottom wall.
Claim 6
Dependent Claim
153 words
A flat bottom bag formed of heat sealable plastic film, said film being formed into an elongated tube having at least one longitudinal seam, said tube being formed with opposed pairs of inwardly folded pleats defined by a longitudinal center fold between a pair of longitudinal fold lines, said pairs of pleats defining opposed end walls of said bag, said bag including opposed sidewalls formed between pairs of adjacent ones of said longitudinal fold lines, a transverse seam joining opposed ones of said sidewalls to close one end of said bag, opposed triangular gussets formed by portions of said pleats sealed to an adjacent portion of respective ones of said sidewalls, said gussets forming a. portion of a bottom wall of said bag, and said one longitudinal seam extends along one of said walls to stiffen said bag in the open position to maintain said bag freestanding and supported by said bottom wall.
Claim 7
Dependent Claim
142 words
A flat bottom bag formed of heat sealable tubular plastic material, said bag having opposed parallel sidewalls and opposed parallel end walls formed by four spaced apart longitudinal folds, a transverse bottom seal formed by joining said sidewalls along one transverse edge of said bag, and a transverse fold line across each of said sidewalls defining a juncture of said sidewalls with a bottom wall defined by said transverse fold line, opposed triangular gussets formed by a lower portion of said end walls, respectively, joined to said bottom wall and delimited by converging lines which extend from opposed ones of said transverse fold lines to said transverse bottom seam, said bag further including a plurality of longitudinal corrugations formed in said sidewalls adapted to increase the longitudinal stiffness of said sidewalls to assist in maintaining said bag freestanding in the open position.
Claim 8
Dependent Claim
142 words
A flat bottom bag formed of heat sealable tubular plastic material, said bag having opposed parallel sidewalls and opposed parallel end walls formed by four spaced apart longitudinal folds, a transverse bottom seal formed by joining said sidewalls along one transverse edge of said bag, and a transverse fold line across each of said sidewalls defining a juncture of said sidewalls with a bottom wall defined by said transverse fold line, opposed triangular gussets formed by a lower portion of said end walls, respectively, joined to said bottom wall and delimited by converging lines which extend from opposed ones of said transverse fold lines to said transverse bottom seam, said bag further including a plurality of longitudinal corrugations formed in said sidewalls adapted to increase the longitudinal stiffness of said sidewalls to assist in maintaining said bag freestanding in the open position.
Claim 9
Dependent Claim
112 words
A flat bottom bag formed of heat sealable plastic film, said film being formed into an elongated tube having at least one longitudinal seam, said bag including opposed sidewalls formed between longitudinal fold lines on said tube, a transverse seam joining opposed ones of said sidewalls to close one end of said bag, wherein said one longitudinal seam is formed by a longitudinal band of predetermined width formed by joining portions of said walls of said tube together and a bead formed along the outer edge of said band, said one longitudinal seam extending along one of said walls to stiffen said bag in the open position to maintain said bag freestanding.
Claim 10
Dependent Claim
112 words
A flat bottom bag formed of heat sealable plastic film, said film being formed into an elongated tube having at least one longitudinal seam, said bag including opposed sidewalls formed between longitudinal fold lines on said tube, a transverse seam joining opposed ones of said sidewalls to close one end of said bag, wherein said one longitudinal seam is formed by a longitudinal band of predetermined width formed by joining portions of said walls of said tube together and a bead formed along the outer edge of said band, said one longitudinal seam extending along one of said walls to stiffen said bag in the open position to maintain said bag freestanding.
Claim 11
Dependent Claim
222 words
A flat bottom bag formed of heat sealable plastic film having a nominal thickness of .2 to .5 mils, said film being formed into an elongated tube having at least one longitudinal heat sealed seam, said tube being formed with opposed pairs of inwardly folded pleats defined by a longitudinal center fold disposed between a pair of longitudinal fold lines, said pairs of pleats defining opposed end walls of said bag, said bag including opposed sidewalls formed between pairs of adjacent ones of said longitudinal fold lines, a transverse heat sealed seam joining opposed ones of said sidewalls to close one end of said bag, opposed triangular gussets formed by a portion of said pleats heat sealed to an adjacent portion of respective ones of said sidewalls, said gussets forming a portion of a bottom wall of said bag, wherein there is also provided a plurality of heat pressed longitudinal corrugations formed in said sidewalls and extending generally parallel to said longitudinal seam, a transverse crease formed in said sidewalls across said corrugations and said longitudinal seam, said crease defining fold lines forming a juncture between said sidewalls and said bottom wall in the bag open condition, said longitudinal seam and said corrugations being operable to stiffen said bag in the open position to maintain said bag freestanding on said bottom wall.
Claim 12
Dependent Claim
222 words
A flat bottom bag formed of heat sealable plastic film having a nominal thickness of .2 to .5 mils, said film being formed into an elongated tube having at least one longitudinal heat sealed seam, said tube being formed with opposed pairs of inwardly folded pleats defined by a longitudinal center fold disposed between a pair of longitudinal fold lines, said pairs of pleats defining opposed end walls of said bag, said bag including opposed sidewalls formed between pairs of adjacent ones of said longitudinal fold lines, a transverse heat sealed seam joining opposed ones of said sidewalls to close one end of said bag, opposed triangular gussets formed by a portion of said pleats heat sealed to an adjacent portion of respective ones of said sidewalls, said gussets forming a portion of a bottom wall of said bag, wherein there is also provided a plurality of heat pressed longitudinal corrugations formed in said sidewalls and extending generally parallel to said longitudinal seam, a transverse crease formed in said sidewalls across said corrugations and said longitudinal seam, said crease defining fold lines forming a juncture between said sidewalls and said bottom wall in the bag open condition, said longitudinal seam and said corrugations being operable to stiffen said bag in the open position to maintain said bag freestanding on said bottom wall.
Claim 13
Independent Claim
175 words
A method of forming a flat bottom bag from plastic film, said bag being formed such that when opened has opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: providing a length of said plastic film and forming said length of film into an elongated tube having at least one longitudinal seam along said length of film; forming said length of film with opposed longitudinal inwardly folded pleats between opposed sidewalls of said length of film; pressing said length of film to form longitudinally extending corrugations in said sidewalls; forming a transverse crease at a predetermined point on said length of film to define transverse fold lines between said sidewalls and said bottom wall; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a triangular shaped gusset extending between said transverse fold lines and across said bottom wall; and heat sealing said sidewalls to each other along a transverse line to form a center seam of said bottom wall.
Claim 14
Independent Claim
175 words
A method of forming a flat bottom bag from plastic film, said bag being formed such that when opened has opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: providing a length of said plastic film and forming said length of film into an elongated tube having at least one longitudinal seam along said length of film; forming said length of film with opposed longitudinal inwardly folded pleats between opposed sidewalls of said length of film; pressing said length of film to form longitudinally extending corrugations in said sidewalls; forming a transverse crease at a predetermined point on said length of film to define transverse fold lines between said sidewalls and said bottom wall; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a triangular shaped gusset extending between said transverse fold lines and across said bottom wall; and heat sealing said sidewalls to each other along a transverse line to form a center seam of said bottom wall.
Claim 15
Independent Claim
195 words
A method of forming a plurality of flat bottom bags from a continuously formed tube of plastic film, said bags being formed such that when opened have opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: forming a continuous blown seamless plastic tube; collapsing said tube between opposed roller means and between opposed pleat forming guides wherein said tube is formed with opposed longitudinal inwardly folded pleats between opposed sidewalls; pressing said collapsed tube to form longitudinally extending corrugations in said sidewalls; forming a transverse crease at spaced apart intervals on said tube to define transverse fold lines between said sidewalls and said bottom of respective ones wall of said bags; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a triangular shaped gusset extending between said transverse fold lines and across said bottom wall; heat sealing said sidewalls along a transverse line to form a center seam of said bottom wall; and cutting said tube adjacent said center seam to define the bottom end of one bag and the top end of another bag formed of said tube.
Claim 16
Independent Claim
195 words
A method of forming a plurality of flat bottom bags from a continuously formed tube of plastic film, said bags being formed such that when opened have opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: forming a continuous blown seamless plastic tube; collapsing said tube between opposed roller means and between opposed pleat forming guides wherein said tube is formed with opposed longitudinal inwardly folded pleats between opposed sidewalls; pressing said collapsed tube to form longitudinally extending corrugations in said sidewalls; forming a transverse crease at spaced apart intervals on said tube to define transverse fold lines between said sidewalls and said bottom of respective ones wall of said bags; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a triangular shaped gusset extending between said transverse fold lines and across said bottom wall; heat sealing said sidewalls along a transverse line to form a center seam of said bottom wall; and cutting said tube adjacent said center seam to define the bottom end of one bag and the top end of another bag formed of said tube.
Claim 17
Independent Claim
244 words
A method of forming a plurality of flat bottom bags from a continuously formed tube of plastic film, said bags being formed such that when opened have opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: forming a continuous blown seamless plastic film tube; collapsing said tube to a substantially flat band having opposed sidewalls; passing said tube through means for forming at least one continuous longitudinal band seal; slitting said tube along said band seal to form at least two continuous tubes having at least one longitudinal sealed seam; inflating said tubes and collapsing said tubes between opposed roller means and between opposed pleat forming guides wherein said tubes each are formed with opposed longitudinal inwardly folded pleats between said sidewalls; pressing said collapsed tubes to form longitudinally extending corrugations; forming a transverse crease at spaced apart intervals on said tubes to define a transverse fold line between said sidewalls and said bottom wall; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a gusset extending between said transverse fold lines and across said bottom wall; heat sealing said sidewalls of each of said tubes along a transverse line to form a center seam of said bottom wall; and cutting said tubes adjacent said center seam to define the bottom end of one bag and the top end of another bag formed of each of said tubes.
Claim 18
Independent Claim
244 words
A method of forming a plurality of flat bottom bags from a continuously formed tube of plastic film, said bags being formed such that when opened have opposed longitudinal side and end walls and a generally rectangular integral bottom wall, said method comprising the steps of: forming a continuous blown seamless plastic film tube; collapsing said tube to a substantially flat band having opposed sidewalls; passing said tube through means for forming at least one continuous longitudinal band seal; slitting said tube along said band seal to form at least two continuous tubes having at least one longitudinal sealed seam; inflating said tubes and collapsing said tubes between opposed roller means and between opposed pleat forming guides wherein said tubes each are formed with opposed longitudinal inwardly folded pleats between said sidewalls; pressing said collapsed tubes to form longitudinally extending corrugations; forming a transverse crease at spaced apart intervals on said tubes to define a transverse fold line between said sidewalls and said bottom wall; heat sealing a portion of each of said sidewalls to said pleats, respectively, to form a gusset extending between said transverse fold lines and across said bottom wall; heat sealing said sidewalls of each of said tubes along a transverse line to form a center seam of said bottom wall; and cutting said tubes adjacent said center seam to define the bottom end of one bag and the top end of another bag formed of each of said tubes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.