US 2007/0175819 A1 · FABRICATION OF FILTER ELEMENTS USING POLYOLEFINS HAVING CERTAIN RHEOLOGICAL PROPERTIES

Abstract

The present disclosure relates to filter elements and more particularly to filter elements prepared from improved polyolefin polymers, presently preferably polypropylene, characterized by a specific rheology. Most particularly, the present disclosure relates to polypropylene that has a specific molecular weight and molecular weight distribution, among other properties and/or characteristics, and/or polypropylene that has been adjusted in viscosity, molecular weight and molecular weight distribution, among other properties and/or characteristics, and its use in making depth filter elements. The present disclosure further relates to processes and/or systems for producing improved polyolefin polymers, e.g., polypropylenes and their use in fabricating advantageous filter elements.

Claims30

Dependent claims

A method of manufacturing polypropylene filter elements comprising:

providing a die;
operatively positioning a support surface proximate the die;
processing polypropylene into nonwoven polypropylene fibers;
forming polypropylene filter elements having an inner and an outer surface by depositing the nonwoven polypropylene fibers on the support surface proximate the die, the polypropylene having an MFI of about 35 to about 380;
operatively positioning structure for withdrawing the polypropylene filter elements from the support surface proximate the die;
withdrawing the polypropylene filter elements from the surface, the polypropylene filter elements exhibiting a void volume greater than about 70%;
and
machining at least one groove in the outer surface of the polypropylene filter elements such that the surface area of the outer surface of the polypropylene filter element is increased.

5 more elements

Dependencies are inferred from the claim text.

Fabrication of filter elements using polyolefins having certain rheological properties

Life of this patent

Fabrication of filter elements using polyolefins having certain rheological properties

Life of this patent

Abstract

Claims30