US4242295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacturing flat plastic net
Assignee: DuPont Canada Inc
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Filing: 1979-04-02
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Granted: 1980-12-30
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Expires: 1999-04-02
Abstract
Abstract The invention provides a process and apparatus for manufacturing flat plastic net. Tubular plastic net is made by extruding plastic material through coaxial circular counter-rotating die members to form a net structure having a plurality of crossing strands. The angular displacement of successive longitudinally-aligned junctions of the crossing strands is controlled, preferably by controlling the relative counter-rotation of the extrusion die members, and successive longitudinally aligned junctions are cut longitudinally within each junction. The tubular net so cut is opened out to form flat net. The flat net so produced, the edges of which are characterized by successive longitudinal edge junctions, in which each edge junction is cut longitudinally within the junction, is particularly useful for fencing material, for example.
Inventors
- 👤 Thomas Urquhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:53
CPC Classifications
B; B26; B26D; B26D3/00; B26D3/001; B29; B29C; B29C48/00; B29C48/03; B29C48/05; B29C48/09; B29C48/10; B29C48/13; B29L; B29L2028/00; Y; Y10; Y10S; Y10S264/00; Y10S264/08; Y10S264/81; Y10T; Y10T156/00; Y10T156/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A process for manufacturing flat net from tubular plastic net, comprising the steps of (a) extruding plastic material through coaxial circular counter-rotating die members so as to form, about an axis of extrusion, a tubular net structure comprising a plurality of crossing strands; (b) controlling the angular displacement of successive substantially longitudinally-aligned junctions of the crossed strands about the axis of extrusion and relative to a fixed plane passing through the axis of extrusion at a pre-determined value, to minimize said angular displacement; (c) cutting successive longitudinally-aligned junctions longitudinally and within each junction, along at least one line of successively longitudinally-aligned junctions, such that the tubular net is adapted to be opened into flat net; and (d) advancing the net under tension during the extrusion and cutting steps.
Claim 2
Dependent Claim
128 words
A process for manufacturing flat net from tubular plastic net, comprising the steps of (a) extruding plastic material through coaxial circular counter-rotating die members so as to form, about an axis of extrusion, a tubular net structure comprising a plurality of crossing strands; (b) controlling the angular displacement of successive substantially longitudinally-aligned junctions of the crossed strands about the axis of extrusion and relative to a fixed plane passing through the axis of extrusion at a pre-determined value, to minimize said angular displacement; (c) cutting successive longitudinally-aligned junctions longitudinally and within each junction, along at least one line of successively longitudinally-aligned junctions, such that the tubular net is adapted to be opened into flat net; and (d) advancing the net under tension during the extrusion and cutting steps.
Claim 3
Dependent Claim
36 words
The process according to claim 1 wherein the angular displacement of successive longitudinally-aligned junctions relative to the fixed plane through the axis of extrusion is minimized by controlling the relative counter-rotation of the extrusion die members.
Claim 4
Dependent Claim
19 words
The process according to claim 1 wherein the cut tubular net is subsequently opened out of form flat net.
Claim 5
Dependent Claim
19 words
The process according to claim 2 wherein the cut tubular net is subsequently opened out to form flat net.
Claim 6
Dependent Claim
16 words
The process according to claim 2 wherein the plastic material is a polymer of a 1-olefin.
Claim 7
Dependent Claim
23 words
The process according to claim 5 wherein each strand of said 1-olefin polymer has a weight of between 11 and 13 g/m length.
Claim 8
Dependent Claim
26 words
The process according to claim 4, 5 or 6 wherein the plastic material is a plastic material selected from the group consisting of polyethylene or polypropylene.
References Cited (Backward Citations)
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US3551543A
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US3557268A
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US3674898A
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US4057449A
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US4123491A
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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) | 1983-12-30 | 1984-06-30 | 1984-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-30 | 1988-06-30 | 1988-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-30 | 1992-06-30 | 1992-12-30 | $7700.00 | Window Closed / Lapsed |