US3593074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and process
Assignee: EIDP Inc
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Filing: 1969-12-22
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Granted: 1971-07-13
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Expires: 1989-12-22
Abstract
Abstract A process for preparing fibrous sheets of organic synthetic polymers in which a filamentary web is entrained in a gaseous stream flowing in a path toward a receiving surface and the web is electrostatically charged before being collected, the improvement being confining the gaseous flow before charging by directing it through a critically dimensioned passage which converges in the direction of flow. The apparatus includes an element which together with the target plate of the charging device for electrostatically charging the fibers structurally defines the passage.
Inventors
- 👤 Lawrence Isakoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:17
CPC Classifications
D; D04; D04H; D04H3/00; D04H3/08; D04H3/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
47 words
The apparatus as defined in claim 1, the ratio of the distance from a point along said edge having a straight line distance one inch from said midpoint to said plate and the midpoint distance to said plate being in the range of from 1.0 to 3.25.
Claim 2
Dependent Claim
53 words
The apparatus as defined in claim 2, where said midpoint distance is in the range from 0.03 inch to 0.25 inch. 4 The apparatus as defined in claim 3, including means for mounting said element for swinging movement toward and away From said plate; and means for biasing said element toward said plate.
Claim 3
Dependent Claim
78 words
A process for forming fibrous sheets that includes the steps of entraining a web in a gaseous stream flowing downwardly toward a collecting means, electrostatically charging said web, and collecting said web in a tensionless state wherein the improvement comprises confining the gaseous stream flow prior to the charging step by directing said flow through a passage converging in the direction of flow to an outlet having a minimum width dimension of from 0.03 to about 0.05 inch.
Claim 4
Dependent Claim
19 words
The process of claim 5 said width dimension being in the range of from about 0.03 to 0.25 inch.
References Cited (Backward Citations)
US3387326A
Cited
GB1134685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |