The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Aug. 12, 2008

Filed:

Jul. 17, 2003
Applicants:

Takuro Nishimura, Minami-Ashigara, JP;

Tadahiro Tsujimoto, Minami-Ashigara, JP;

Yukihiro Katai, Minami-Ashigara, JP;

Inventors:

Takuro Nishimura, Minami-Ashigara, JP;

Tadahiro Tsujimoto, Minami-Ashigara, JP;

Yukihiro Katai, Minami-Ashigara, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 37/02 (2006.01);
U.S. Cl.
CPC ...
Abstract

The solution film-forming method is provided in which the absolute filtration accuracy for a cellulose acylat solution can be improved and filtration throughput can be increased without reducing the pore size of a filtering material. A dope stock solution to be filtrated is first introduced into a body feed tank and a filter aid from a filter aid tank is added and dispersed. As the filter aid, an aid including SiO2 in 50% or more and a cellulose-based aid are mixed for use. The dope stock solution in which the filter aid is dispersed is introduced into a filter machine and subjected to filtration while forming a cake on the surface of the filtering material. After the filtration, a cleaning solvent is supplied in circulation from a cleaning solvent tank, and the cake is discharged as slurry. The filter aid is separated from the slurry by a separating device and burned in a burning device. Then, a regenerated filter aid is sent to the filter aid tank. After the cleaning, a precoat liquid in which the filter aid is dispersed is supplied from a precoat tank to the filter machine to form a precoat layer on the surface of the filtering material.


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