Process for extruding semi-permeable membrane having separate hollow passageways
US5171493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1989 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Dec 22, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D69/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for the production of a porous organic material, in particular an organic semi-permeable membrane, provided with a plurality of separate passageways, comprising dissolving a polymer in a solvent, using a drawplate comprising needles having a shape conjugate with that of the passageways and external dimensions comprising between 0.7 and 1.2 times those of said passageways and an extrusion orifice of a conjugate fome to that of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of said extrudate, injecting around the needles a solution having a viscosity greater than 500 millipascal-second, introducing into the interior of the conduits of the drawplate a centering fluid which is a non-solvent with respect to the polymer and able to precipitate the polymeric solution, causing the extrudate to travel from the output of the drawplate a distance da in a gaseous atmosphere which is non-precipitating with respect to the polymeric solution such that 500.times.e<da<0.8 m, wherein e is the maximum distance, recovering the extrudate in a liquid bath which is precipitating for the polymeric solution, and taking up the precipitated extrudate with a line…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.