Ceramic honeycomb and method

DETAILED DESCRIPTION OF THE PREFERRED METHODS Honeycomb material can be made in two basic ways.
The first is to take sheets or webs of material, which have typically been preimpregnated with a suitable resin, and corrugate the webs into half honeycomb shapes.
The high points or nodes on the webs are then bonded to the high points or nodes on adjacent webs to create the honeycomb cavities, typically four or six sided.
Alternatively, a flat sheet can be secured between the corrugated ribbons to create the cavities.
Another way to create honeycomb is to take flat sheets and put glue lines between each sheet at staggered places.
After doing so, the stack of sheets are then expanded to create expanded honeycomb material.
Various techniques for making honeycomb are disclosed in U.
S.
Pat.
No.
5,312,511 to Fell titled Apparatus for the Preparation of Thermoplastic Honeycomb, the disclosure of which is incorporated by reference.
U.
S.
Pat.
No.
5,078,818 to Jong H.
Han titled Method for Producing a Fiber-Reinforced Ceramic Honeycomb Panel discloses the manufacture of fiber-reinforced ceramic honeycomb by the use of a liquid impregnant which is convertible to a ceramic material upon exposure to elevated temperatures.
With the present invention, webs of material are made of fabric woven from fibers, at least some of which are ceramic fibers.
The ceramic fibers can be, for example, carbon fibers, Nicalon.
TM.
ceramic-grade or low volume resistivity grade silicon oxycarbide fibers, made by Nippon Carbon Co.
of Japan, Nextel.
TM.
aluminosilicate fibers, made by 3M Corporation of Minnesota, HPZ ceramic fibers made by Dow Corning, silicon carbide fibers produced by Dow Corning, or graphite fibers made by various manufacturers.
For chemical absorptive applications, the used high surface area carbon fiber is preferred.
All of these can be woven with other electrically conductive or absorptive ceramic fibers or with non-conductive and/or non-absorptive ceramic fibers.
If desired, the conductive ceramic fibers can be non-uniformly woven into the web of material so that the electrical conductivity along one portion of the web differs from that along another portion of the web