Abstract: The present invention is related to a liquid filter having a filtration part for filtration of liquid, said filtration part at least comprising a first filtration layer consisting of a first material; and a second filtration layer consisting of a second material, characterized in that the filtration of liquid in the filtration part is in the order of: a first filtration, taking place at said second filtration layer; and a second filtration, taking place at said first filtration layer. The present invention is further related to a method for installing the liquid filter.

Abstract: The present invention discloses a method for preparing a polyurethane film, comprising the steps of: i) dissolving polyurethane into a first solvent to form a first solution; ii) dissolving salt into a second solvent to form a second solution; iii) preparing a spinning stock solution by mixing said first solution and said second solution; iv) spinning said spinning stock solution in an electrospinning device to obtain a polyurethane film; v) providing a container to which a third solvent is sprayed; and vi) arranging said polyurethane film in said container for a period of time.

Abstract: The invention provides an enhanced electrospun film made from polyvinylidene fluoride (PVDF) and at least one low-melting-point polymer in a ratio of 99.9:0.1-90:10 by weight, and the low-melting-point polymer having a melting point lower than the polyvinylidene fluoride and a softening point in the range of 110-140° C. The enhanced electrospun film exhibits excellent mechanical properties, higher moisture permeability and hydrostatic pressure resistance. The invention further provides a method for manufacturing the enhanced PVDF electrospun film, and use of the enhanced PVDF electrospun film in preparing a waterproof and moisture permeable product.