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.
Patent No.:
Date of Patent:
Aug. 25, 1987
Filed:
May. 06, 1986
Sven-Ingvar Thorbjornsson, Karlstad, SE;
Lars-Otto Sislegard, Kil, SE;
Sunds Defibrator AB, Sundsvall, SE;
Abstract
A method and apparatus for forming a web having a predetermined grammage profile in its transverse direction is provided. The method includes the steps of introducing a flow of particulate material into the distribution chamber of a forming head through an oscillating nozzle and depositing the material on an air permeable belt to form a web while changes in the upper surface of the web are detected downstream of the distribution chamber, signals are generated in response to any change which are compared with predetermined set points, and an output control signal is generated as a result of the comparison. The pattern of movement of the nozzle is controlled in response to the output control signal to provide the predetermined grammage profile for the web. In addition, the speed of the web may be measured and used to control the frequency of the nozzle so that a web having uniform grammage in the longitudinal direction is also provided. An apparatus for accomplishing each of the steps of the method is additionally provided.