Process for producing a semi-permeable membrane by extrusion
US5089187A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1989 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Dec 22, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01D5/24
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for the production of a porous organic material, in particular a semi-permeable membrane, comprising a plurality of separate passageways, including dissolving a polymer in a solvent, using a drawplate having needles of a shape conjugate with those of the passageways and of external dimensions between 0.7 and 1.2 times those of the passageways and an extrusion orifice of a shape conjugate those of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of the extrudate, injecting around the needles a solution having a viscosity greater than 500 mPa.s and introducing a centering fluid into the interior of these needles, recovering the extrudate at the output of the drawplate in a precipitating medium in such a manner that the extrudate travels in the medium a distance such that 800.times. e<de<3 m, (e representing the maximum distance of travel for a precipitaing fluid for obtaining complete precipitation of the extrudate), and taking up the precipitated extrudate with a linear take-up speed Ve such that Ve/Vs<1.2 (Wv representing the average speed of the extrusion).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.