ELECTRON BEAM INDUCED MODIFICATION OF MEMBRANES BY POLYMERS

摘要

A method and an apparatus are provided for carrying out integrity tests of at least one filter element, arranged within a filter housing, with porous filter materials. Sensors are provided for measuring the sound generated by a test fluid when it flows through the filter element. The method includes applying a test fluid to a first side of the filter materials of the filter element while maintaining a constant fluid pressure, measuring the body-borne sound and/or the vibrations caused by test fluid flowing through the filter materials by sensors, and comparing the body-borne sound and/or the vibrations with the body-borne sound and/or the vibrations of an integral, identical filter element, measured under identical conditions.

主权项

1. A method for producing a microporous membrane on whose surface an electron beam radiation crosslinked polymer is fixed, said method comprising the steps of:
a) providing a microporous starting membrane having outer surfaces and pores with inner surfaces extending between the outer surfaces of the membrane and having a microporous starting membrane permeability, b) impregnating the membrane with an impregnating solution consisting essentially of a solvent and 0.01 to 20 weight percent of a polymer dissolved or dispersed therein to provide an impregnated membrane that has the solvent and the polymer in the pores and on the outer surfaces of the membrane, the polymer being an organic substance with an average molecular weight of at least 500 g/mol being selected from the group consisting of polyethylene glycol, perfluorinated hydrocarbons, polyethylene oxide (PEO), polypropylene oxide (PPO), hydroxyethylcellulose, dextran, hydroxymethylcellulose, PEO-PPO-PEO triblock copolymers, and mixtures thereof; and c) irradiating the impregnated membrane with electron beam radiation using a dose in the range from 1 to 300 kGy to provide a crosslinked reaction product constituting a three-dimensional network formed of the microporous starting membrane and the polymer without any decomposition of the microporous starting membrane; wherein the microporous starting membrane permeability is not reduced by more than 10% by fixing the electron beam radiation crosslinked polymer thereto.