US4134951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of filaments
Assignee: Smith and Nephew Polyfabrik Ltd
•
Filing: 1977-02-23
•
Granted: 1979-01-16
•
Expires: 1997-02-23
Abstract
Abstract An extruded sheet or the like of cold-drawable polymer such as polypropylene is embossed as a molten sheet by a circumferentially multi-grooved roller and stretched in the direction of the embossed grooves to split into filaments along the grooves.
Inventors
- 👤 James Dow
- 👤 Ronald Lloyd
- 👤 Albert G. Patchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:08
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/42; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
130 words
A process for the production of continuous filaments comprising passing a molten deformable polymeric material as a formed flat hot melt sheet into the nip formed between (a) at least one roller having a multiplicity of adjacent fine continuous circumferential grooves and (b) a second roller in pressure contact therewith, at least one of said rollers being maintained at a temperature below the temperature of the molten deformable polymeric material to effect cooling and simultaneously form and solidify said material into a flat body of material having parallel continuous ribs along its longitudinal axis; stretching the ribbed material in a direction substantially parallel to the ribs by an amount sufficient to orient the polymer; and splitting the material longitudinally between the ribs to form longitudinal filaments corresponding to said ribs.
Claim 2
Dependent Claim
130 words
A process for the production of continuous filaments comprising passing a molten deformable polymeric material as a formed flat hot melt sheet into the nip formed between (a) at least one roller having a multiplicity of adjacent fine continuous circumferential grooves and (b) a second roller in pressure contact therewith, at least one of said rollers being maintained at a temperature below the temperature of the molten deformable polymeric material to effect cooling and simultaneously form and solidify said material into a flat body of material having parallel continuous ribs along its longitudinal axis; stretching the ribbed material in a direction substantially parallel to the ribs by an amount sufficient to orient the polymer; and splitting the material longitudinally between the ribs to form longitudinal filaments corresponding to said ribs.
Claim 3
Dependent Claim
34 words
A process as claimed in claim 1 in which the material is extruded as a sheet and thereafter slit into tapes at any stage within the period extending from before embossing to after stretching.
Claim 4
Dependent Claim
17 words
A process as claimed in claim 1 in which the material splits into filaments spontaneously on stretching.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 1 in which the material is subjected to transverse stresses to split it into filaments.
Claim 6
Dependent Claim
14 words
A process as claimed in claim 1 wherein the polymer is a cold-drawing polymer.
Claim 7
Dependent Claim
12 words
A process as claimed in claim 5 wherein the polymer is polypropylene.
Claim 8
Dependent Claim
16 words
A process as claimed in claim 6 wherein polypropylene is extruded at 200° to 300° C.
Claim 9
Dependent Claim
26 words
A process as claimed in claim 1 wherein an extruded sheet is passed through the nip between a single circumferentially grooved roller and a smooth roller.
Claim 10
Dependent Claim
24 words
A process as claimed in claim 1 wherein an extruded sheet is passed through the nip between two circumferentially grooved rollers in pressure contact.
Claim 11
Dependent Claim
16 words
A process as claimed in claim 9 wherein the grooves on each roller are located coincidentally.
Claim 12
Dependent Claim
20 words
A process as claimed in claim 1 where the roller possesses from b 10 to 300 longitudinal grooves per inch.
Claim 13
Dependent Claim
23 words
A process as claimed in claim 1 wherein the grooves are semicircular in cross-section and wherein two coincidentally grooved opposed rollers are used.
Claim 14
Dependent Claim
21 words
A process as claimed in claim 1 wherein the sheet leaving the roller is from 0.001 to 0.02 inches thick overall.
Claim 15
Dependent Claim
27 words
A process as claimed in claim 13 where the material between the ridges of the sheet is less than 50% of the thickness of the sheet overall.
Claim 16
Dependent Claim
19 words
A process as claimed in claim 14 where the material between the ridges is less than 25 microns thick.
Claim 17
Dependent Claim
20 words
A process as claimed in claim 2 wherein an extruded sheet is subdivided into tapes immediately after leaving the die.
Claim 18
Dependent Claim
26 words
A process as claimed in claim 2 wherein an extruded sheet is subdivided into tapes by roller ridges while passing through the nip of embossing rollers.
Claim 19
Dependent Claim
19 words
A process as claimed in claim 2 wherein the sheet is subdivided into tapes after leaving the embossing roller.
Claim 20
Dependent Claim
13 words
A process as claimed in claim 18 wherein subdivision is effected before stretching.
Claim 21
Dependent Claim
18 words
A process as claimed in claim 1 where stretching is effected up to 2000% of the unstretched length.
Claim 22
Dependent Claim
20 words
A process as claimed in claim 20 wherein the polymer is polypropylene and is stretched at 130° - 155° C.
Claim 23
Dependent Claim
16 words
A process as claimed in claim 1 wherein a sheet is stretched with no lateral restraint.
Claim 24
Dependent Claim
16 words
A process as claimed in claim 1 wherein a sheet is stretched with complete lateral restraint.
Claim 25
Dependent Claim
19 words
A process as claimed in claim 1 wherein the individual filaments are split apart by twisting the stretched material.
Claim 26
Dependent Claim
27 words
A process as claimed in claim 1 wherein the individual filaments are split apart by passing a tape of the stretched material through an air venturi passage.
Claim 27
Dependent Claim
32 words
A process as claimed in claim 1 wherein the individual fibres are split apart by winding a tape of stretched material over grooved godet rollers positioned at an angle to one another.
Claim 28
Dependent Claim
26 words
A process as claimed in claim 1 wherein the extruded material is coated on one or both sides with a preformed polymer sheet before being melt-embossed.
Claim 29
Dependent Claim
18 words
A process as claimed in claim 27 wherein a non-cold-drawing polymer is used as the preformed polymer sheet.
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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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |