| Pleated sintered metal fiber medium -> Monitor Keywords |
|
|
  Pleated sintered metal fiber mediumUSPTO Application #: 20080096041Title: Pleated sintered metal fiber medium Abstract: A sintered metal fiber medium as subject of the invention comprising at least one pleat, which pleat comprising a first leg being present according to a first plane, and a second leg being present according to a second plane. The first plane and the second plane intersect along an intersecting line according to a dihedral angle θ. The pleat comprises a bending part for coupling the first and the second leg. The medium has an average thickness at the legs of TI. A sintered metal fiber medium as subject of the invention is characterized in that the bending part comprises at least one distinct linear zones, which is substantially parallel to the intersecting line, in which linear zone, the medium has a minimum thickness Tb, which Tb is smaller than TI. In the linear zone or zones of the bending part, the thickness of the medium is reduced, so Tb is less than 0.5 times TI. Further, a method to provide such pleated sintered metal fiber medium is described. (end of abstract)
Agent: Foley And Lardner LLP Suite 500 - Washington, DC, US Inventor: Pieter Rommens USPTO Applicaton #: 20080096041 - Class: 428603000 (USPTO) Related Patent Categories: Stock Material Or Miscellaneous Articles, All Metal Or With Adjacent Metals, Nonplanar Uniform Thickness Or Nonlinear Uniform Diameter (e.g., L-shape) The Patent Description & Claims data below is from USPTO Patent Application 20080096041. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to sintered metal fiber media, and more in particular to pleated sintered metal fiber media and a method for pleating sintered metal fiber media. BACKGROUND OF THE INVENTION [0002] Sintered metal fiber medium is well known in the art. More in particular, it is well known for its use as liquid or gas filtration, such as e.g. polymer and ink jet filtration or hot gas filtration, e.g. soot filtration in diesel exhaust filtration applications. [0003] For most of the applications for which sintered metal fiber medium is used, it is of importance to provide as much filter medium as possible per volume of the filter cartridge in which the medium is used. It is known in the art to pleat the sintered metal fiber medium for making "accordion"--like pleated media. [0004] However, the sintered metal fiber media have the disadvantage that it is difficult to pleat to U-shapes, having a small angle between the two legs, e.g. an angle smaller than 90.degree. or in extreme, having legs being essentially parallel to each other, this is an angle being 0.degree.. [0005] U.S. Pat. No. 6,276,045B1 describes a method to pleat sintered metal fiber medium, meanwhile avoiding deleterious deformation of the sintered metal fiber medium at the flanks of the pleats. [0006] Pleating of sintered metal fiber media may cause rupture of the sintering points at the outer side of the bend, especially when the angle over which the sintered metal fiber medium is bend, is larger than 120.degree.. For this reason, bends over an angle of less than 100.degree. are usually avoided, or additional means are provided at the outer bend side of the medium to avoid such ruptures. Such means may be metal scrims or grid. [0007] In case ruptures of sintering points occur, the mechanical properties of the sintered metal fiber medium are changed too much at the locations of the fiber ruptures to guarantee sufficient strength during use of the pleated sintered metal fiber medium. [0008] Sintered metal fiber medium may be pleated while the angles between the legs are kept relatively large. [0009] In this case, in which the pleats have the tendency to look more like "V-shapes" or providing more "zigzag-"like sintered metal fiber medium, the increase of sintered metal fiber medium per volume unit of filtration cartridge is limited. [0010] Sintered metal fiber mediua being pleated according to a U-shaped pleat having a required small angle between the planes of the legs, such as smaller than 90.degree., or even having essentially parallel legs can be obtained using a bending part which provides a large distance between the legs at the coupling with the bending part, in which bending part having too small bending radii are avoided. In case the distance is made too small, e.g. smaller than 5 times the thickness of the medium, the sintered metal fiber medium at the inner side of the U-shape, has the tendency to upset in an uncontrolled way, which may even lead to rupture of the sintered structure at this inner side. [0011] But due to the larger distances to be chosen, an increase of sintered metal fiber medium per volume unit of the filtration cartridge is limited due to these large distances between the legs of the U-shape. [0012] In diesel soot filtration applications, the trapped soot may be removed from the sintered metal fiber medium filter by heating the medium using its electrical conductivity. Electrical current is supplied to, and conducted by the medium from one end of the medium to the other. Due to the joule effect, the sintered metal fiber medium is heated and the combustible soot is ignited, thus removed as the carbon and other C-comprising particulates are converted into CO.sub.2. In case the sintered metal fiber medium is used for such electrically regenerating filtration purposes and when ruptures of sintering points tend to occur, the pleated sintered metal fiber medium has the tendency to burn through at the location of fiber ruptures due to a too large current passing through the reduced mount of sintered fibers at the ruptures. SUMMARY OF THE INVENTION [0013] It is an object of the present invention to provide a pleated sintered metal fiber medium overcoming the problems of prior art. [0014] It is also an object of the present invention to provide a method to pleat sintered metal fiber medium avoiding rupture of the sintering points at the outer side of the bend. [0015] It is also an object of the present invention to provide a method to pleat sintered metal fiber medium, providing the sintered metal fiber medium having a little angle between the two legs of the pleat, this is less than 90.degree., or even having essentially parallel legs, avoiding rupture of the sintered structure at the outer surface of the bending part and having controlled upsetting at this inner side of the U-shape, avoiding rupture of the sintered structure at this inner side of the U-shape. [0016] A sintered metal fiber medium as subject of the invention comprising at least one pleat, which pleat comprising a first leg being present according to a first plane, and a second leg being present according to a second plane. The first plane and the second plane intersect along an intersection line at a dihedral angle .theta.. The pleat comprises a bending part for coupling the first and the second leg. The medium has an average thickness at the legs of TI. The bending part comprises at least a first distinct linear zone, which zone is substantially parallel to the intersection line, in which first linear zone the medium has a minimum thickness Tb, smaller than TI. A sintered metal fiber medium as subject of the invention is characterized in that Tb is smaller than 0.5 times TI, more preferred smaller than or equal to 0.45 times TI or even smaller than or equal to 0.4 times TI. [0017] So in the linear zone or zones of the bending part, the thickness of the medium is reduced. [0018] The term "minimum thickness" is to be understood at the smallest thickness which is measured in the linear zone over which the thickness of the medium is reduced. [0019] It was further found that the width W of the linear zone, over which width the medium thickness is reduced to some extent, preferably is equal or more than TI-Tb, and more preferred equal or more than 1.5 times TI-Tb or even equal or more than 1.75 times TI-Tb such as equal to or more than 2 times TI-Tb. The width W is measured as the average distance between the two edges of the linear zone when the two planes of the two legs are aligned. [0020] It was found that such sintered metal fiber medium as subject of the invention can be pleated more easily using this linear zone as a bending axis, providing two legs which are present according to two intersecting planes, which intersect at a dihedral angle smaller than 180.degree. and preferably larger than 90.degree., without the risk of obtaining cracks or rupture of the sintered metal fiber medium at the outer surface of the pleat. [0021] The bending part may comprise only one linear zone in which the medium thickness is reduced to a minimum thickness Tb according to the present invention. Continue reading... Full patent description for Pleated sintered metal fiber medium Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Pleated sintered metal fiber medium patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Pleated sintered metal fiber medium or other areas of interest. ### Previous Patent Application: Method for making a rolling-lobe air spring and apparatus therefor and a rolling-lobe air spring having a flanged plate Next Patent Application: Process for the preparation of metallic wools with a controlled degree of surface oxidation and fibres deriving from them: products obtained, and their use as supports to obtain metaalic core composite materials for a variety of applications Industry Class: Stock material or miscellaneous articles ### FreshPatents.com Support Thank you for viewing the Pleated sintered metal fiber medium patent info. IP-related news and info Results in 1.95765 seconds Other interesting Feshpatents.com categories: Electronics: Semiconductor , Audio , Illumination , Connectors , Crypto , |
||
