US4249978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a heat resistant carton
Assignee: NATIONS BANK OF GEORGIA NA
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Filing: 1979-04-19
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Granted: 1981-02-10
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Expires: 1999-04-19
Abstract
Abstract A method of forming a heat-sealable carton having a pair of mating surfaces to be sealed includes the steps of coating at least one of the carton surfaces with a heat-activated thermosetting adhesive, spraying a fine mist of a water-based adhesive which exhibits high contact tackiness when dry, to form a discontinuous film on the coated surface, heating the water-based adhesive coated surface to a temperature sufficient to dry the water-based adhesive and activate the thermosetting adhesive, placing the mating carton surfaces in contact with each other and applying pressure for a time sufficient to seal the contacting surfaces together. A carton formed by the method is provided with flaps sealed by the combination of thermosetting heat-activated adhesive and high tack water-based adhesive. This allows the mating surfaces to be rapidly sealed by automatic carton closing apparatus and results in a sealed carton which exhibits good seal integrity at high temperatures. A carton formed in this manner is useful, for example, as a food container which can be placed directly in an oven to heat the contents thereof, with the carton seal being unaffected by the oven heat.
Inventors
- 👤 Thomas R. Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:42
CPC Classifications
B; B65; B65B; B65B51/00; B65B51/10; B65B51/20; B31; B31B; B31B50/00; B31B50/26; B31B50/36; B31B50/38; B31B50/60; B31B50/64; Y; Y10; Y10S; Y10S229/00; Y10S229/902; Y10S229/903; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24843; Y10T428/31504; Y10T428/31786; Y10T428/31797
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
110 words
A method of bonding a carton having at least a pair of mating surfaces to be sealed, the sealed surfaces exhibiting a high resistance to heat after sealing, comprising the steps of: coating at least one of said carton surfaces with a heat-activated thermosetting adhesive; applying a water-based adhesive emulsion exhibiting high contact tackiness when substantially dry on at least one of said surfaces to form a discontinuous film so that intermittent areas of said thermosetting adhesive are defined and exposed; heating at least said water-based and thermosetting adhesive coated surfaces to a temperature sufficient to at least partially dry said water-based adhesive and activate said thermosetting adhesive for sealing;
Claim 2
Independent Claim
110 words
A method of bonding a carton having at least a pair of mating surfaces to be sealed, the sealed surfaces exhibiting a high resistance to heat after sealing, comprising the steps of: coating at least one of said carton surfaces with a heat-activated thermosetting adhesive; applying a water-based adhesive emulsion exhibiting high contact tackiness when substantially dry on at least one of said surfaces to form a discontinuous film so that intermittent areas of said thermosetting adhesive are defined and exposed; heating at least said water-based and thermosetting adhesive coated surfaces to a temperature sufficient to at least partially dry said water-based adhesive and activate said thermosetting adhesive for sealing;
Claim 3
Dependent Claim
34 words
subsequently placing said mating carton surfaces in contact with each other; setting said thermosetting adhesive against reactivation by heat after sealing; and applying pressure for a time sufficient to seal said contacting surfaces together.
Claim 4
Dependent Claim
34 words
subsequently placing said mating carton surfaces in contact with each other; setting said thermosetting adhesive against reactivation by heat after sealing; and applying pressure for a time sufficient to seal said contacting surfaces together.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said heat-activated thermosetting adhesive comprises a polyester resin.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said water-based adhesive is sprayed as a fine mist.
Claim 7
Dependent Claim
17 words
The method of claim 3 wherein said water-based adhesive comprises an aqueous emulsion of polyvinyl acetate which.
Claim 8
Dependent Claim
36 words
The method of claim 1 wherein said surfaces coated with said adhesives are heated to a temperature within the range of 110° C.-290° C. to dry said water-based adhesive and to activate said heat-activated thermosetting adhesive.
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein said step of heating said coated surfaces comprises the step of directing a stream of heated air against said coated surfaces.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein said pressure is applied for a time period within the range of 0.5 seconds to 2.5 seconds.
Claim 11
Dependent Claim
23 words
The method of claim 1 wherein only one of said carton surfaces is coated with both said heat-activated adhesive and said water-based adhesive.
Claim 12
Dependent Claim
30 words
The method of claim 1 wherein both of said carton surfaces are coated with said heat-activated thermosetting adhesive and one of said coated surfaces is coated with said water-based adhesive.
Claim 13
Dependent Claim
37 words
The methods of either claims 9 or 10 wherein said carton surface not coated with said water-based adhesive is not heated during said heating step and acts as a heat sink for said heated surface during sealing.
Claim 14
Dependent Claim
22 words
The method of claim 1 wherein both of said carton surfaces are coated with said heat-activated thermosetting adhesive and said water-based adhesive.
Claim 15
Independent Claim
158 words
A method of bonding a carton having at least a pair of mating surfaces to be sealed, the sealed surfaces exhibiting a high resistance to heat after sealing comprising the steps of: coating at least one of said carton surfaces with a heat-activated thermosetting adhesive; spraying a water-based adhesive emulsion only on said one coated carton surface, said water-based adhesive being sprayed as a fine mist sufficiently light to form a discontinuous film on said coated surface so that intermittent areas of said thermosetting adhesive are defined and exposed, said water-based adhesive exhibiting high contact tackiness when substantially dry; heating only said coated carton surface to a temperature sufficient to at least partially dry said water-based adhesive and activate said thermosetting adhesive for sealing; subsequently placing said mating carton surfaces in contact with each other; setting said thermosetting adhesive against reactivation by heat after sealing; and applying pressure for a time sufficient to seal said contacting surfaces together.
Claim 16
Independent Claim
158 words
A method of bonding a carton having at least a pair of mating surfaces to be sealed, the sealed surfaces exhibiting a high resistance to heat after sealing comprising the steps of: coating at least one of said carton surfaces with a heat-activated thermosetting adhesive; spraying a water-based adhesive emulsion only on said one coated carton surface, said water-based adhesive being sprayed as a fine mist sufficiently light to form a discontinuous film on said coated surface so that intermittent areas of said thermosetting adhesive are defined and exposed, said water-based adhesive exhibiting high contact tackiness when substantially dry; heating only said coated carton surface to a temperature sufficient to at least partially dry said water-based adhesive and activate said thermosetting adhesive for sealing; subsequently placing said mating carton surfaces in contact with each other; setting said thermosetting adhesive against reactivation by heat after sealing; and applying pressure for a time sufficient to seal said contacting surfaces together.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |