US3789710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for producing a porous plastic film
Assignee: Applied Synthetics Corp
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Filing: 1971-09-10
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Granted: 1974-02-05
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Expires: 1991-09-10
Abstract
Abstract The present invention provides a method and apparatus for producing a porous plastic film and contemplates, in a preferred embodiment, feeding a continuous web of plastic film material by feed means, such as rollers, past a drum having a plurality of outwardly extending projections or tips mounted on the eternal surface thereof, whereby the tips are heated to a predetermined temperature and the plastic film is brought in contact with said tips to cause minute, microscopic reinforced apertures to be burned in said plastic film to form pores or apertures therein. Thereafter, if necessary, the tips are then heated to a higher temperature to burn off any residue of plastic material remaining thereon and then cooled to the desired predetermined temperature before again being brought into contact with the continuously fed plastic film.
Inventors
- 👤 P Silverstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:21
CPC Classifications
B; B26; B26F; B26F1/00; B26F1/24; Y; Y10; Y10T; Y10T83/00; Y10T83/04; Y10T83/0405; Y10T83/041; Y10T83/0414; Y10T83/0481; Y10T83/242; Y10T83/283; Y10T83/293; Y10T83/929; Y10T83/9314
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
164 words
An apparatus for making a plastic film material porous, comprising: means for burning aertures in said plastic film material; means for moving said plastic film material into and out of burning engagement with said burning means so as to provide an apertured plastic film material; said burning means comprising a plurality of heatable elements, heating means for heating said elements to a first predetermined temperature, and said heatable elements upon contacting said plastic film material for a predetermined period of time burning said apertures therethrough; said first predetermined temperature being sufficiently high to burn off excess plastic deposited on said heatable elements during the burning of said apertures; and cooling means, said cooling means being applied to said heatable elements after they have been heated to said first predetermined temperature, and being operable to reduce the temperature of said heated elements to a second predetermined temperature, and said heated elements at said second predetermined temperature engaging said plastic film to burn said apertures therein.
Claim 2
Independent Claim
164 words
An apparatus for making a plastic film material porous, comprising: means for burning aertures in said plastic film material; means for moving said plastic film material into and out of burning engagement with said burning means so as to provide an apertured plastic film material; said burning means comprising a plurality of heatable elements, heating means for heating said elements to a first predetermined temperature, and said heatable elements upon contacting said plastic film material for a predetermined period of time burning said apertures therethrough; said first predetermined temperature being sufficiently high to burn off excess plastic deposited on said heatable elements during the burning of said apertures; and cooling means, said cooling means being applied to said heatable elements after they have been heated to said first predetermined temperature, and being operable to reduce the temperature of said heated elements to a second predetermined temperature, and said heated elements at said second predetermined temperature engaging said plastic film to burn said apertures therein.
Claim 3
Dependent Claim
46 words
An apparatus in accordance with claim 1, wherein said plastic film material is a web of material, and said moving means unrolls said web of material continuously past said burning means and then rerolls the same in the form of an apertured web of plastic material.
Claim 4
Dependent Claim
58 words
An apparatus in accordance with claim 1, wherein said apparatus includes a drum, means for rotating said drum about its longitudinal axis, said moving means being operable to move said plastic film material past the drum tangent to the outer surface of said drum, and means for mounting said heatable elements on the outer surface of said drum.
Claim 5
Dependent Claim
42 words
An apparatus in accordance with claim 3, wherein said heating means is disposed adjacent the external surface of said drum at a position which is subsequent in time to the burning of the apertures in the plastic film by said heated elements.
Claim 6
Dependent Claim
50 words
An apparatus in accordance with claim 4, wherein said cooling means is disposed adjacent the external surface of the drum at a position which is prior in time to the burning of the apertures in the plastic film and subsequent to the heating of said elements by said heating means.
Claim 7
Dependent Claim
37 words
An apparatus in accordance with claim 5, further comprising a wiper bar disposed adjacent said drum and in an interfering position with respect to said heatable elements, whereby said heatable elements as wiped as said drum rotates.
Claim 8
Dependent Claim
24 words
An apparatus in accordance with claim 6, wherein said heatable elements are in the form of U-shaped staples secured to reinforced carrier strip means.
Claim 9
Dependent Claim
16 words
An apparatus in accordance with claim 3, wherein said cooling means is an air cooling means.
Claim 10
Dependent Claim
17 words
An apparatus in accordance with claim 3, wherein said cooling means is a liquid solvent cooling means.
Claim 11
Dependent Claim
15 words
An apparatus in accordance with claim 3, wherein said heating means is a gas heater.
Claim 12
Dependent Claim
50 words
An apparatus in accordance with claim 3, wherein said means for mounting said heatable elements on the outer surface of said drum includes at least one carrier strip secured to said drum and disposed on the outer surface thereof, and means for connecting said heatable elements to said carrier strip.
Claim 13
Dependent Claim
28 words
An apparatus in accordance with claim 11, wherein the apertures formed by the burning of said plastic film by said heated elements have a substantially irregular shaped configuration.
Claim 14
Dependent Claim
32 words
An apparatus in accordance with claim 12, wherein the peripheral areas surrounding said apertures are thickened by the formation of the apertures and serve to reinforce the peripheral areas against tearing thereat.
Claim 15
Dependent Claim
49 words
An apparatus in accordance with claim 11, wherein said heatable elements are disposed upon the drum surface so as to form a perforated pattern having an irregular geometric configuration upon said plastic film material, whereby there are no distinct longitudinal and lateral tear lines in said plastic film material.
Claim 16
Dependent Claim
32 words
An apparatus in accordance with claim 12, wherein said irregular geometric configuration provides a spiral perforated pattern on said plastic film material having a helix angle of about 4* to about 5*.
Claim 17
Independent Claim
135 words
A method of making a plastic film material porous comprising the steps of: heating a plurality of heatable elements to a first predetermined temperature, passing said plastic film material over said heated elements in burning engagement therewith so as to burn a high multiplicity of relatively small apertures in said film material; said first predetermined temperature being sufficiently high to burn off excess plastic deposited on said heatable elements during the burning of said apertures in said film material, and cooling said heated elements to a second predetermined temperature prior to the burning engagement of said heated elements and said plastic film material; said second predetermined temperature being sufficiently high to burn said apertures in said film material but being less than said first predetermined temperature; and said burned apertures having a reinforced peripheral edge.
Claim 18
Independent Claim
135 words
A method of making a plastic film material porous comprising the steps of: heating a plurality of heatable elements to a first predetermined temperature, passing said plastic film material over said heated elements in burning engagement therewith so as to burn a high multiplicity of relatively small apertures in said film material; said first predetermined temperature being sufficiently high to burn off excess plastic deposited on said heatable elements during the burning of said apertures in said film material, and cooling said heated elements to a second predetermined temperature prior to the burning engagement of said heated elements and said plastic film material; said second predetermined temperature being sufficiently high to burn said apertures in said film material but being less than said first predetermined temperature; and said burned apertures having a reinforced peripheral edge.
Claim 19
Dependent Claim
18 words
The method of claim 16, wherein the step of cooling is performed by means of an air cooler.
Claim 20
Dependent Claim
18 words
The method of claim 16, wherein the step of cooling is performed by means of a liquid solvent.
Claim 21
Dependent Claim
25 words
The method of claim 16, wherein the step of heating said heatable elements to said first predetermined temperature is by means of a gas heater.
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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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |