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US3752457A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and equipment for continuously spinning and stretching synthetic filaments

Assignee: SNIA Viscosa SpA
•
Filing: 1970-12-01
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Granted: 1973-08-14
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Expires: 1990-12-01
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Abstract

Abstract A method and apparatus for continuously carrying out spinning and stretching operations on extruded synthetic filaments, wherein, between a conventional spinning apparatus and a conventional stretching apparatus for continuous treatment of the filaments, a bending and stretching action is imparted to the filaments by means of stationary bending means adapted to exert a predetermined frictional resistance on the running filaments.

Inventors

  • 👤 P Parmeggiani
  • 👤 D Nicita
  • 👤 Alo B D

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 17:36
CPC Classifications
D; D02; D02J; D02J1/00; D02J1/22; D02J1/228; D01; D01D; D01D5/00; D01D5/12; D01D5/16; D02J1/225; D02J1/226

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 186 words
In a melt spinning method for continuously spinning, stretching and winding-up synthetic filaments comprising extruding filaments from a spinneret under a reduced tension of about 0.5 glden; cooling and conditioning said filaments by passing said filaments through quenching and conditioning environments; mechanically stretching said filaments in a stretching zone by passing said filaments over an upstream godet rotating at a first speed and then passing said filaments over a downstream godet rotating at a second speed higher than said first speed; and windingingup the thus stretched filaments; the improvement comprising; treating said filaments by an intermediate processing operation immediately prior to said step of mechanically stretching, said intermediate operation comprising bending said filaments in a first bending direction around a first circular arc, and then bending said filaments in a second opposite bending direction around a second circular arc, the path of said filaments during said bending steps having two circular arcs of angular amplitude between 20* and 130*, thereby increasing the tension by about 0.1-0.2 glden of and imparting a slight incremental stretch to said filaments between said second circular arc and said upstream godet.
Claim 2
Dependent Claim 186 words
In a melt spinning method for continuously spinning, stretching and winding-up synthetic filaments comprising extruding filaments from a spinneret under a reduced tension of about 0.5 glden; cooling and conditioning said filaments by passing said filaments through quenching and conditioning environments; mechanically stretching said filaments in a stretching zone by passing said filaments over an upstream godet rotating at a first speed and then passing said filaments over a downstream godet rotating at a second speed higher than said first speed; and windingingup the thus stretched filaments; the improvement comprising; treating said filaments by an intermediate processing operation immediately prior to said step of mechanically stretching, said intermediate operation comprising bending said filaments in a first bending direction around a first circular arc, and then bending said filaments in a second opposite bending direction around a second circular arc, the path of said filaments during said bending steps having two circular arcs of angular amplitude between 20* and 130*, thereby increasing the tension by about 0.1-0.2 glden of and imparting a slight incremental stretch to said filaments between said second circular arc and said upstream godet.
Claim 3
Dependent Claim 28 words
An improved method according to claim 1, where in the radii of curvature of said first and second circular arcs are in the range of from 2-10 mm.
Claim 4
Dependent Claim 24 words
An improved method according to claim 2, whErein the ratio of said radii of curvature is in the range of from 1:2 to 2:1.
Claim 5
Dependent Claim 48 words
An improved method according to claim 1, wherein said filaments are of a polyester material, said step of mechanically stretching said filaments includes stretching said polyester filaments within the range of from 2.5-3.0 g/den., thereby providing an elongation ratio of from 1:3.8 to 1:4.4 to said polyester filaments.

References Cited (Backward Citations)

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US3338992A Cited
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US3259681A Cited
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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) 1976-08-13 1977-02-12 1977-08-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-08-13 1981-02-12 1981-08-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-08-13 1985-02-12 1985-08-14 $7700.00 Window Closed / Lapsed

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