US3600875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for wrapping objects in thermoplastic films
Assignee: WR Grace and Co
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Filing: 1969-10-21
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Granted: 1971-08-24
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Expires: 1989-10-21
Abstract
Abstract A packaging apparatus and a method in which an object wrapped in a thermoplastics film is subject to three heating steps, each step taking place at a higher temperature than the previous one. During the first heating step the film is heated only sufficiently to maintain it in a wrapped condition; during the second the film is shrunk; and during the third the film is completely heat-sealed.
Inventors
- 👤 Robert Konrad Buob
- 👤 Giorgio Giraudi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:25
CPC Classifications
B; B65; B65B; B65B53/00; B65B53/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
126 words
A method of producing a wrapped, sealed object, said method comprising the steps of: a. folding a heat-sealable thermoplastics film to form a package around an object; b. applying sufficient heat to the film in a first heating step to cause the film to remain in a folded condition with folds of the film overlapped but not sealed together; c. applying sufficient heat to the film in a second heating step to raise its temperature to a higher value than that of the film during the first heating step, effective to shrink the film around the object; and d. heating the film to a higher temperature than in the second heating step, effective to completely heat-seal the film in the overlapped folds formed in step (a).
Claim 2
Independent Claim
126 words
A method of producing a wrapped, sealed object, said method comprising the steps of: a. folding a heat-sealable thermoplastics film to form a package around an object; b. applying sufficient heat to the film in a first heating step to cause the film to remain in a folded condition with folds of the film overlapped but not sealed together; c. applying sufficient heat to the film in a second heating step to raise its temperature to a higher value than that of the film during the first heating step, effective to shrink the film around the object; and d. heating the film to a higher temperature than in the second heating step, effective to completely heat-seal the film in the overlapped folds formed in step (a).
Claim 3
Dependent Claim
33 words
A method as specified in claim 1, wherein during the second heating step the film is passed in contact with a shrinking plate at a temperature in the range 115* to 145* C.
Claim 4
Dependent Claim
26 words
A method as specified in claim 2, wherein the film is passed in contact with a pair of shrinking plates, at least one of which reciprocates.
Claim 5
Dependent Claim
29 words
A method as specified in claim 1, wherein the temperature to which the film is heated during the third heating step is in the range 150* to 180* C.
Claim 6
Dependent Claim
25 words
A method as specified in claim 1, wherein the third heating step comprises subjecting the film to the action of a pair of reciprocating hotplates.
Claim 7
Dependent Claim
101 words
Packaging apparatus comprising, in combination: a. means for folding a filM around an object; b. at a first heating station, means for applying sufficient heat to said film to cause said film to remain in a wrapped condition with folds of said film overlapped; c. at a second heating station, means for applying heat at a temperature higher than that of the first heating station to heat-shrink said film; and, d. at a third heating station, means for heating said film to a higher temperature than at the second heating station, whereby the overlapped folds of said film are heat-sealed completely.
Claim 8
Dependent Claim
101 words
Packaging apparatus comprising, in combination: a. means for folding a filM around an object; b. at a first heating station, means for applying sufficient heat to said film to cause said film to remain in a wrapped condition with folds of said film overlapped; c. at a second heating station, means for applying heat at a temperature higher than that of the first heating station to heat-shrink said film; and, d. at a third heating station, means for heating said film to a higher temperature than at the second heating station, whereby the overlapped folds of said film are heat-sealed completely.
Claim 9
Dependent Claim
26 words
Apparatus as specified in claim 6, wherein a pair of hotplates are located at said second heating station at least one of said hotplates being reciprocable.
Claim 10
Dependent Claim
20 words
Apparatus as specified in claim 6, wherein pairs of reciprocable hotplates are located at said first and third heating stations.
Claim 11
Dependent Claim
61 words
Auxiliary apparatus for use in conjunction with packaging apparatus, said auxiliary apparatus comprising means for shrinking a film around an object and means for heat-sealing said film without means for folding said film around said object or means for holding said film in a wrapped condition, and said auxiliary apparatus further including means for receiving an object from said packaging apparatus.
Claim 12
Dependent Claim
61 words
Auxiliary apparatus for use in conjunction with packaging apparatus, said auxiliary apparatus comprising means for shrinking a film around an object and means for heat-sealing said film without means for folding said film around said object or means for holding said film in a wrapped condition, and said auxiliary apparatus further including means for receiving an object from said packaging apparatus.
Claim 13
Dependent Claim
23 words
Apparatus as specified in claim 9, wherein said shrinking means comprises a pair of heat-shrinking plates, at least one of which is reciprocable.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |