Systems for producing a plurality of different microporous phase inversion membrane each having any one of a plurality of different pore sizes from a single master dope batch

A system for continuously controlling the mixing temperature of a ternary phase inversion polymer master batch of dope formulated at a predetermined polymer to non-solvent to solvent ratio at a temperature no higher than within about .+-.1.0.degree. C. of a target formulation mixing temperature, to establish a first dope temperature memory, the system comprising:

• a storage vessel for maintaining the ternary phase inversion polymer master batch of dope at a controlled maximum storage temperature, the storage temperature being nominally lower than the target formulation mixing temperature;
• pump means, operatively connected to the storage vessel, for sequentially transporting portions of the dope from the storage vessel to a dope processing site;
• and
• heating means, operatively positioned between the pump means and the dope processing site, for increasing the temperature of at least a small portion of the dope being transported form the vessel, as the small portion of the dope moves through the heating means, to a temperature no higher than within about .+-.0.2.degree. C. of any one of a plurality of possible different predetermined temperatures to establish any one of a possible plurality of different second dope temperature memories.

A system for processing a single ternary phase inversion polymer master dope batch having a predetermined minimum pore size forming capability in microporous phase inversion membranes into any one of a plurality of different sized pores in microporous phase inversion membrane, the system comprising:

• a vessel for containing a ternary phase inversion polymer master dope, the dope having been exposed to a mixing temperature to establish a first dope temperature memory, the vessel and the dope contained therein being maintained at a temperature nominally lower than the mixing temperature, such temperature being sufficient to stabilize and maintain the mixture after cooling from the mixing temperature;
• at least one pump, operatively connected to the vessel, for transporting the dope from the vessel to a dope processing site;
• and
• means, operatively connected to the vessel, for elevating the temperature of at least a portion of the ternary phase inversion polymer master dope batch to a temperature no higher than within about .+-.0.2.degree. C. of any one of a plurality of possible different predetermined temperatures to establish any one of a possible plurality of different second dope temperature memories, the any one of the second temperature memories being higher than the first temperature memory.