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Title: System to continuously produce carbon fiber via microwave assisted plasma processing

Abstract

A method for continuously processing carbon fiber including establishing a microwave plasma in a selected atmosphere contained in an elongated chamber having a microwave power gradient along its length defined by a lower microwave power at one end and a higher microwave power at the opposite end of the elongated chamber. The elongated chamber having an opening in each of the ends of the chamber that are adapted to allow the passage of the fiber tow while limiting incidental gas flow into or out of said chamber. A continuous fiber tow is introduced into the end of the chamber having the lower microwave power. The fiber tow is withdrawn from the opposite end of the chamber having the higher microwave power. The fiber to is subjected to progressively higher microwave energy as the fiber is being traversed through the elongated chamber.

Inventors:
; ;
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1344536
Patent Number(s):
9,427,720
Application Number:
14/222,827
Assignee:
UT-BATELLE, LLC (Oak Ridge, TN) ORNL
DOE Contract Number:
AC05-00OR22725
Resource Type:
Patent
Resource Relation:
Patent File Date: 2014 Mar 24
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

White, Terry L., Paulauskas, Felix L., and Bigelow, Timothy S. System to continuously produce carbon fiber via microwave assisted plasma processing. United States: N. p., 2016. Web.
White, Terry L., Paulauskas, Felix L., & Bigelow, Timothy S. System to continuously produce carbon fiber via microwave assisted plasma processing. United States.
White, Terry L., Paulauskas, Felix L., and Bigelow, Timothy S. Tue . "System to continuously produce carbon fiber via microwave assisted plasma processing". United States. doi:. https://www.osti.gov/servlets/purl/1344536.
@article{osti_1344536,
title = {System to continuously produce carbon fiber via microwave assisted plasma processing},
author = {White, Terry L. and Paulauskas, Felix L. and Bigelow, Timothy S.},
abstractNote = {A method for continuously processing carbon fiber including establishing a microwave plasma in a selected atmosphere contained in an elongated chamber having a microwave power gradient along its length defined by a lower microwave power at one end and a higher microwave power at the opposite end of the elongated chamber. The elongated chamber having an opening in each of the ends of the chamber that are adapted to allow the passage of the fiber tow while limiting incidental gas flow into or out of said chamber. A continuous fiber tow is introduced into the end of the chamber having the lower microwave power. The fiber tow is withdrawn from the opposite end of the chamber having the higher microwave power. The fiber to is subjected to progressively higher microwave energy as the fiber is being traversed through the elongated chamber.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Aug 30 00:00:00 EDT 2016},
month = {Tue Aug 30 00:00:00 EDT 2016}
}

Patent:

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  • A system to continuously produce fully carbonized or graphitized carbon fibers using microwave-assisted plasma (MAP) processing comprises an elongated chamber in which a microwave plasma is excited in a selected gas atmosphere. Fiber is drawn continuously through the chamber, entering and exiting through openings designed to minimize in-leakage of air. There is a gradient of microwave power within the chamber with generally higher power near where the fiber exits and lower power near where the fiber enters. Polyacrylonitrile (PAN), pitch, or any other suitable organic/polymeric precursor fibers can be used as a feedstock for the inventive system. Oxidized or partiallymore » oxidized PAN or pitch or other polymeric fiber precursors are run continuously through a MAP reactor in an inert, non-oxidizing atmosphere to heat the fibers, drive off the unwanted elements such as oxygen, nitrogen, and hydrogen, and produce carbon or graphite fibers faster than conventionally produced carbon fibers.« less
  • A method for continuously processing carbon fiber including establishing a microwave plasma in a selected atmosphere contained in an elongated chamber having a microwave power gradient along its length defined by a lower microwave power at one end and a higher microwave power at the opposite end of the elongated chamber. The elongated chamber having an opening in each of the ends of the chamber that are adapted to allow the passage of the fiber tow while limiting incidental gas flow into or out of said chamber. A continuous fiber tow is introduced into the end of the chamber havingmore » the lower microwave power. The fiber tow is withdrawn from the opposite end of the chamber having the higher microwave power. The fiber to is subjected to progressively higher microwave energy as the fiber is being traversed through the elongated chamber.« less
  • The present invention introduces a novel method for producing an undulated surface on composite fibers using plasma technology and microwave radiation. The undulated surface improves the mechanical interlocking of the fibers to composite resins and enhances the mechanical strength and interfacial sheer strength of the composites in which they are introduced.
  • The disclosed invention introduces a novel method of manufacturing carbon and/or graphite fibers that avoids the high costs associated with conventional carbonization processes. The method of the present invention avoids these costs by utilizing plasma technology in connection with electromagnetic radiation to produce carbon and/or graphite fibers from fully or partially stabilized carbon fiber precursors. In general, the stabilized or partially stabilized carbon fiber precursors are placed under slight tension, in an oxygen-free atmosphere, and carbonized using a plasma and electromagnetic radiation having a power input which is increased as the fibers become more carbonized and progress towards a finalmore » carbon or graphite product. In an additional step, the final carbon or graphite product may be surface treated with an oxygen-plasma treatment to enhance adhesion to matrix materials.« less
  • A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads. 9 figs.