US3566726A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making perforated film
Assignee: PANTASOTE CO OF NEW YORK Inc
•
Filing: 1968-06-13
•
Granted: 1971-03-02
•
Expires: 1988-06-13
Abstract
Abstract Unsupported thermoplastic films having elastic memory are perforated and/or embossed and perforated while heated to a plastic temperature by feeding the film, while heated to a temperature where it is plastic, together with a suitable web, such as a release paper, into the bite between a perforating (and/or perforating and embossing) roll and a backing roll, so that during the perforating the film is pressed against the web and the pins of the perforating roll enter at least partway into the web. After cooling the web is removed. The material from the perforations is caused to flow into the balance of the film, thickening and reinforcing the same instead of being punched out and lost as is the case when a cold nonplastic film is perforated.
Inventors
- 👤 George A Politis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:40
CPC Classifications
B; B26; B26D; B26D7/00; B26D7/08; B26D7/10; B26F; B26F1/00; B26F1/24; Y; Y10; Y10T; Y10T83/00; Y10T83/04; Y10T83/0405; Y10T83/041; Y10T83/283; Y10T83/869; Y10T83/8725; Y10T83/929; Y10T83/9314
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
A method of perforating unsupported thermoplastic film which comprises heating said thermoplastic film at a temperature at which it is plastic but at which it still has elastic memory, passing said thusly heated strip into the bite between a perforating roll and a backup roll, simultaneously passing a web of nonplastic material into the bite between said perforating roll and backup roll, said film being disposed between said web and said perforating roll and being in pressure contact with said web while in said bite, said perforating roll having perforating means extending into said web while in said bite and being at a temperature substantially below the temperature at which said film is plastic, maintaining said web in contact with said perforated film until said film has cooled below the plastic state, and then stripping the web from said perforated film, whereby said web prevents perforations in said film from closing due to elastic memory when said perforating means is withdrawn from said film.
Claim 2
Independent Claim
164 words
A method of perforating unsupported thermoplastic film which comprises heating said thermoplastic film at a temperature at which it is plastic but at which it still has elastic memory, passing said thusly heated strip into the bite between a perforating roll and a backup roll, simultaneously passing a web of nonplastic material into the bite between said perforating roll and backup roll, said film being disposed between said web and said perforating roll and being in pressure contact with said web while in said bite, said perforating roll having perforating means extending into said web while in said bite and being at a temperature substantially below the temperature at which said film is plastic, maintaining said web in contact with said perforated film until said film has cooled below the plastic state, and then stripping the web from said perforated film, whereby said web prevents perforations in said film from closing due to elastic memory when said perforating means is withdrawn from said film.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said perforating roll also has a contour suitable for embossing said film.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said perforating roll is of metal and is unheated.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein said film is a compounded polyvinyl chloride.
Claim 6
Dependent Claim
28 words
The method of claim 3 wherein said web is a fibrous material suitably treated to prevent adhesion to said film when the latter is in the plastic state.
Claim 7
Dependent Claim
13 words
The method of claim 3 wherein said web is a suitable release paper.
Claim 8
Dependent Claim
29 words
A perforated and unsupported film of polyvinyl chloride having thickened peripheral wall portions immediately surrounding the perforations formed by flow of plastic material during the forming of said perforations.
Claim 9
Dependent Claim
29 words
A perforated and unsupported film of polyvinyl chloride having thickened peripheral wall portions immediately surrounding the perforations formed by flow of plastic material during the forming of said perforations.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |