Patent US3914960A successfully refreshed from Google Patents.
US3914960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for continuously producing preoxidized textile products
Assignee: BP Chemicals Hitco Inc
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Filing: 1974-02-11
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Granted: 1975-10-28
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Expires: 1994-02-11
Abstract
Abstract A continuous web apparatus for manufacturing high modulus graphite fibers and fabric is disclosed. Precursor fabric is incrementally stretched dynamically by applying an initially high tension to the fabric and heating the fabric to stretching temperature while maintaining the stretch ratio substantially constant. The tension is then reduced to a low value before preoxidation temperature is reached and increases during preoxidation to a higher value due to shrinking and/or application of tension to the fabric. The fabric is then continuously fired and graphitized. The stretching unit includes a plurality of rolls successively driven at a controlled faster speed and successively heated to a higher temperature. The fabric is heated quickly between each roll to a temperature intermediate to the temperature of the rolls by applying a jet of hot air to the fabric from a hot air sparger air knife so that substantially all the stretching occurs during the interroll travel.
Inventors
- 👤 Donald W Mcguffin
- 👤 Richard J Larsen
- 👤 Robert W Mitchell
- 👤 Bernard E Caruso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:49
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/32; D01F9/20; D01F9/21; D01F9/22; D01F9/225
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
AN APPARATUS FOR CONTINUOUSLY PRODUCING A PREOXIDED, ELONGATED GRAPHITE PRODUCT FROM A CARBONIZABLE PRECURSOR MATERIAL COMPRISING IN COMBINATION: FIRST TENSIONING MEANS FOR APPLYING AN INTIAL HIGH TENSION TO CONTINUOUSLY MOVING MATERIAL FOR ESTABLISHING A FIRST LEVEL OF ELONGATION, MEANS FOR INCREMENTALLY HEATING SAID MATERIAL UP TO 450*F AND FOR INCREMENTALLY STRETCHING SAID MATERIAL TO REDUCE THE TENSION ON SAID MATERIAL TO A LOW VALUE INCLUDING A PLURALITY OF ROLLS, MEANS FOR INDEPENDENTLY DRIVING THE ROLLS AT A SUCCESSIVELY HIGHER SPEED, AND FIRST HEATING MEANS FOR HEATING SAID ROLLS TO SUCCESSIVELY HIGHER TEMPERATURES UP TO 450*F, OXIDATION MEANS INCLUDING MEANS FOR PREOXIDIZING SAID MATERIAL AND FOR RETENSIONING SAID MATERIAL TO A TENSION LEVEL INTERMEDIATE SAID HIGH AND LOW TENSION LEVELS AND BELOW THE BREAKING TENSION OF SAID MATERIAL, AND FIRING MEANS FOR CONVERTING THE PREOXIDIZED MATERIAL TO GRAPHITE MATERIAL.
Claim 2
Independent Claim
138 words
AN APPARATUS FOR CONTINUOUSLY PRODUCING A PREOXIDED, ELONGATED GRAPHITE PRODUCT FROM A CARBONIZABLE PRECURSOR MATERIAL COMPRISING IN COMBINATION: FIRST TENSIONING MEANS FOR APPLYING AN INTIAL HIGH TENSION TO CONTINUOUSLY MOVING MATERIAL FOR ESTABLISHING A FIRST LEVEL OF ELONGATION, MEANS FOR INCREMENTALLY HEATING SAID MATERIAL UP TO 450*F AND FOR INCREMENTALLY STRETCHING SAID MATERIAL TO REDUCE THE TENSION ON SAID MATERIAL TO A LOW VALUE INCLUDING A PLURALITY OF ROLLS, MEANS FOR INDEPENDENTLY DRIVING THE ROLLS AT A SUCCESSIVELY HIGHER SPEED, AND FIRST HEATING MEANS FOR HEATING SAID ROLLS TO SUCCESSIVELY HIGHER TEMPERATURES UP TO 450*F, OXIDATION MEANS INCLUDING MEANS FOR PREOXIDIZING SAID MATERIAL AND FOR RETENSIONING SAID MATERIAL TO A TENSION LEVEL INTERMEDIATE SAID HIGH AND LOW TENSION LEVELS AND BELOW THE BREAKING TENSION OF SAID MATERIAL, AND FIRING MEANS FOR CONVERTING THE PREOXIDIZED MATERIAL TO GRAPHITE MATERIAL.
Claim 3
Dependent Claim
40 words
An apparatus according to claim 1 in which said incremental means further includes second heater means positioned between adjacent rolls for heating said precursor material to a temperature intermediate said adjacent rolls during travel of said material between said rolls.
Claim 4
Dependent Claim
44 words
An apparatus according to claim 1 in which said oxidation means includes an enclosure for receiving an oxidizing gas, means for heating said gas to a temperature between 400*F and 525*F and retensioning roll means for applying said intermediate tension to said oxidized material.
Claim 5
Dependent Claim
26 words
An apparatus according to claim 1 in which said material is in fabric form and said roll means have an elongated width for receiving said fabric.
Claim 6
Dependent Claim
17 words
An apparatus according to claim 1 in which the incremental heating means includes from 2-7 discrete stages.
Claim 7
Dependent Claim
46 words
An apparatus according to claim 1 in which said heating means includes an internal heater disposed within said rolls and further including second heating means for heating said material to a temperature intermediate the temperature of adjacent rolls during travel of the material between said rolls.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |