US4597749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic bag having reinforced handles and method of manufacture
Assignee: Mobil Oil AS
•
Filing: 1985-06-25
•
Granted: 1986-07-01
•
Expires: 2005-06-25
Abstract
Abstract The present invention relates to a thermoplastic bag which is characterized by having a pair of carrying handles formed integrally with the bag walls and extending upwardly from opposite sides of an open mouth portion of the bag. The handle members are reinforced and comprise at least two layers of thermoplastic material, one of the layers forming the bag body and handles and the other layer serving as a reinforcement layer. The reinforcement layer is provided only in the handle areas of the bag structure.
Inventors
- 👤 Dennis O'Brien
- 👤 Graham Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:09
CPC Classifications
B; B65; B65D; B65D33/00; B65D33/06; B65D33/065; B31; B31B; B31B70/00; B31B70/74; B31B70/81; Y; Y10; Y10S; Y10S493/00; Y10S493/916; Y10S493/926
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
174 words
A method of forming a thermoplastic bag structure comprising the steps of: advancing a flattened tubular plastic film having inwardly directed gussets on opposite side edges thereof to an unfolding station; unfolding at said unfolding station a flap of sid flattened tubular plastic film for each of said gussets, said unfolded flaps being on the same side of said flattened tubular plastic film; advancing said unfolded flattened tubular plastic film to a reinforcement strip application station and applying thereat reinforcing strips to flaps forming said gussets, said reinforcing strips being applied to areas of said plastic film which are to form handles of a completed bag; refolding the flaps of said gussets; severing said plastic film into segments; heat sealing top and bottom edges of said segments; and cutting a mouth opening in a top portion of each said segment to form a bag having front and rear bag walls and handles on opposite sides of said mouth opening which are extensions of said front and rear walls and reinforced by said reinforcing strips.
Claim 2
Independent Claim
174 words
A method of forming a thermoplastic bag structure comprising the steps of: advancing a flattened tubular plastic film having inwardly directed gussets on opposite side edges thereof to an unfolding station; unfolding at said unfolding station a flap of sid flattened tubular plastic film for each of said gussets, said unfolded flaps being on the same side of said flattened tubular plastic film; advancing said unfolded flattened tubular plastic film to a reinforcement strip application station and applying thereat reinforcing strips to flaps forming said gussets, said reinforcing strips being applied to areas of said plastic film which are to form handles of a completed bag; refolding the flaps of said gussets; severing said plastic film into segments; heat sealing top and bottom edges of said segments; and cutting a mouth opening in a top portion of each said segment to form a bag having front and rear bag walls and handles on opposite sides of said mouth opening which are extensions of said front and rear walls and reinforced by said reinforcing strips.
Claim 3
Dependent Claim
18 words
A method as in claim 1, further comprising the step of applying said reinforcing strips by an adhesive.
Claim 4
Dependent Claim
28 words
A method as in claim 1, further comprising the step of forming said bag walls and handles and said reinforcement strips of a linear low density polyethylene film.
Claim 5
Dependent Claim
40 words
A method as in claim 3, further comprising the steps of forming said bag walls of a film having a thickness of approximately 0.5 mil and forming said reinforcement strips of a film having a thickness of approximately 1 mil.
Claim 6
Dependent Claim
35 words
A method as in claim 1, further comprising the steps of forming said bag walls and handles of a linear low density polyethylene film and forming said reinforcement strips of a high density polyethylene film.
Claim 7
Dependent Claim
40 words
A method as in claim 5, further comprising the steps of forming said bag walls of a film having a thickness of approximately 0.5 mil and forming said reinforcement strips of a film having a thickness of approximately 0.6 mil.
Claim 8
Dependent Claim
47 words
A method as in claim 1, further comprising the step of spacing said reinforcement strips from a top edge of the handles of said bag structure by an amount which is sufficient to allow heat sealing of said top edge without heat sealing through said reinforcement strips.
Claim 9
Dependent Claim
22 words
A method as in claim 7, further comprising the step of spacing said reinforcement strips from said top edge by approximately 1/4".
Claim 10
Dependent Claim
25 words
A method as in claim 1, further comprising the step of extending said reinforcement strips just beyond said lowermost portion of said open mouth portion.
Claim 11
Dependent Claim
28 words
A method as in claim 8, further comprising the step of extending said reinforcement strips to greater than 1" below said lowermost portion of said open mouth portion.
Claim 12
Dependent Claim
26 words
A method as in claim 10, further comprising the step of extending said reinforced strips to a range of 1" to 3" below said lowermost portion.
Claim 13
Dependent Claim
33 words
A method as in claim 1, further comprising the step of forming the reinforcement strips of a polymer having as higher tensile strength than a polymer forming said front and rear bag walls.
References Cited (Backward Citations)
US3070278A
Cited
US3154238A
Cited
US3180557A
Cited
GB1071296A
Cited
CH405057A
Cited
US3255951A
Cited
US3352411A
Cited
US3454441A
Cited
US3468470A
Cited
US3482761A
Cited
US3797733A
Cited
GB1465695A
Cited
US4085822A
Cited
US4125220A
Cited
US4346834A
Cited
US4464157A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |