Method of forming and shaping plasticized mixtures by low to moderate shear extrusion
US6113829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 1998 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | Jul 15, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B38/0006
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for forming and shaping powder mixtures involves compounding, homogenizing, and plasticizing components to form a mixture. The components are 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 components are chosen to result in improved wet green strength in the subsequently formed green body. The compounding is done by the steps of dry-mixing the powder material, surfactant and binder to form a uniform blend, adding the solvent to the resulting dry blend, and thereafter adding the non-solvent to the blend. The mixture is shaped by passing it through a low to moderate shear extruder, and then through a die to form a green body. The compounding and shaping steps are carried out at a temperature of no greater than ambient temperature. The method is especially suitable for RAM extrusion. Among the advantages, the method results in higher extrusion velocity, throughputs, and wet green strength, without increasing pressures and torques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.