METHOD OF FORMING CERAMIC STRINGS AND FIBERS
A method of forming a ceramic fiber comprising the steps of forming a slip comprised of water, ceramic powder, and a binding agent; forming a generally continuous stream of the slip; introducing the stream of the slip into a chemical solution at a concentration wherein the binding agent causes the ceramic slip to form a gelled fiber; removing the gelled fiber from the chemical solution; drying the gelled fiber to remove moisture therefrom; and firing the fiber to produce a ceramic.
1 . A method of forming a ceramic fiber, comprising the steps of:
forming a slip comprised of water, ceramic powder, and a binding agent;
forming a generally continuous stream of said slip;
introducing said stream of slip into a chemical solution at a concentration wherein said binding agent causes said ceramic slip to form a gelled fiber;
removing said gelled fiber from said chemical solution;
drying said gelled fiber to remove moisture therefrom; and
firing said fiber to produce a ceramic.
2 . A method as defined in claim 1 , wherein said slip is comprised of 20% to 80% ceramic particles.
3 . A method as defined in claim 2 , wherein about 90% of said ceramic powder has a particle size less than 42 microns (μm).
4 . A method as defined in claim 2 , wherein said slip has a viscosity of between 150 centipoise and 3,500 centipoise.
5 . A method as defined in claim 1 , wherein said binding agent is an alginate.
6 . A method as defined in claim 5 , wherein said binding agent is an ammonia-based alginate.
7 . A method as defined in claim 5 , wherein said binding agent is a sodium-based alginate.
8 . A method as defined in claim 5 , wherein said chemical solution is comprised of calcium chloride (CaCl 2 ).
9 . A method as defined in claim 1 , further comprising:
washing said gelled fiber to reduce the chemical content of said gelled fiber, said washing step being prior to said drying step.
10 . A method as defined in claim 9 , wherein said chemical solution is comprised of calcium chloride (CaCl 2 ).
11 . A method as defined in claim 10 , wherein said gelled fiber is washed until the calcium chloride content of said fibers is between about 0.01% and about 0.8% by weight.
12 . A method as defined in claim 1 , wherein said drying step comprises exposing said gelled fiber to a temperature between about 105° C. and about 150° C. for between two hours and sixteen hours.
13 . A method as defined in claim 1 , wherein said firing step comprises exposing said gelled fiber to a temperature between about 1,300° C. and 1,700° C. for between two hours and six hours.
14 . A method as defined in claim 1 , wherein said calcium chloride (CaCl 2 ) solution is agitated when said slip is introduced thereinto.
15 . A method as defined in claim 1 , wherein said chemical solution is comprised of a calcium chloride (CaCl 2 ) solution that contains about 7% to about 12% by weight calcium chloride (CaCl 2 ).
16 . A method as defined in claim 15 , wherein said calcium chloride (CaCl 2 ) solution has a temperature between 60° F. (15.5° C.) and 140° F. (60° C.).
17 . A method as defined in claim 1 , wherein said gelled fiber is collected in a mold in said calcium chloride (CaCl 2 ) solution until said gelled fiber fills said mold and forms a shape conforming to said mold.
18 . A method as defined in claim 2 , wherein said ceramic slip includes a foaming agent.
19 . A method as defined in claim 1 , wherein said gelled fiber is collected on a moving surface within said chemical solution.