Preparation method of hollow fiber internal pressure composite film

Abstract

The invention discloses a preparation method of a hollow fiber internal pressure composite film, and aims to provide a preparation method of a hollow fiber internal pressure composite film with high supporting property and high pressure resistance. The preparation method comprises the following steps of: uniformly blending an outer layer film forming material, an outer layer film forming diluent and an outer layer film forming additive in a fusing process to obtain a thermally induced phase separation method outer layer film forming system; dissolving and uniformly mixing an inner layer film forming material, an inner layer film forming solvent and an inner layer film pore forming agent to obtain a non-solvent induced phase separation method inner layer film forming system, wherein the inner layer film pore forming agent contains over 70 percent of water-soluble polymer; and extruding and spinning in a composite way by introducing a core liquid into a central pipe, taking the inner layer film forming system as a middle layer and taking the outer layer film forming system as the outside, quickly soaking into a coagulation bath, fully curing an outer layer and an inner layer under the actions of the coagulation bath and the core liquid, and extracting and washing to obtain the hollow fiber internal pressure composite film. The large-inner-diameter hollow fiber internal pressure composite film prepared with the method disclosed by the invention can be used for replacing a tubular film during application.

Description

technical field [0001] The invention belongs to the technical field of hollow fiber membrane preparation, and more specifically relates to a method for preparing a hollow fiber internal pressure composite membrane. Background technique [0002] Hollow fiber membrane, as a high-efficiency separation material, has been widely used in various fields such as water treatment. According to the requirements of use, the hollow fiber membrane with the outer surface as the separation function layer is usually called the hollow fiber outer pressure membrane, and the hollow fiber membrane with the inner surface as the separation function layer is called the hollow fiber inner pressure membrane. For the hollow fiber internal pressure membrane, in order to ensure the smooth flow of the liquid in the hollow fiber tube, it is necessary to maintain a high support of the membrane; The inner diameter, pressure resistance and water hammer impact resistance of the fiber inner pressure membrane;...