Thermally Induced Phase Separation(TIPS） is a method for preparing a polymer membrane by mixing the polymer with a substance that acts as a solvent a high temperature and casting the solution into a film. When the solution is cooled, solidification occurs.
Manufacturing Process Using TIPS
In the first stage the polymer of choice is molten and fed into an extruder. The molten polymer is conveyed to a special mixer together with a solvent/non-solvent mixture. This solvent/non-solvent mixture must be selected so that the polymer is dissolved only above a certain temperature, but that there is no solubility of the polymer at lower temperatures. By intensive mixing of the molten polymer and the solvent/non-solvent mixture at an elevated temperature a homogenous solution is formed.
TIPS Process for Capillary Membranes
This hot solution is then extruded through a spinneret . After the forming step, the extruded melt-blend passes through an air gap and is cooled, either in a quenching bath or on a chill roll. In this step, the solution is cooled down below the dissolving temperature, which leads to a thermally induced phase separation and thus formation of polymer-rich and solvent-rich phase, which finally enables the solidification of the polymer-rich phase.