abstract |
Powder mixtures and a method of forming and shaping the mixtures. The method involves compounding the components of powder materials, binder, solvent for the binder, surfactant, and non-solvent with respect to at least the binder, the solvent, and the powder materials. The non-solvent is lower in viscosity than the binder combined with the solvent. The solvent is present in an amount that is less than the amount that would be present otherwise. The components are mixed and plasticized, and shaped to form a green body. The choice of components results in improved wet green strength in the green body. The method is especially useful for extrusion processing of aqueous binder systems such as water and cellulose ethers and hydrophobic non-solvents, to form structures such as honeycombs. In the body, the ratio, upon subsequent firing, of the isostatic strength to the A-axis strength is at least about 20% higher than in bodies made without the mixture composition of the invention. A honeycomb body having a ratio of the isostatic strength to the A-axis strength of at least about 0.33 upon firing. |