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:
Jul. 22, 2025
Filed:
Aug. 31, 2021
Stora Enso Oyj, Helsinki, FI;
Isto Heiskanen, Imatra, FI;
Kaj Backfolk, Lappeenranta, FI;
Anna Kauppi, Lappeenranta, FI;
Katja Lyytikäinen, Imatra, FI;
Jukka Kankkunen, Imatra, FI;
Juha Korvenniemi, Oriniemi, FI;
Stora Enso OYJ, Helsinki, FI;
Abstract
The present invention relates to a method for manufacturing a multilayer film comprising microfibrillated cellulose (MFC) in a paper-making machine, the method comprising the steps of: a) forming a bottom web layer by applying a first pulp suspension comprising at least 50% by dry weight of cellulose based fibrous material having an SR (Schopper-Riegler) value in the range of 18-75 on a bottom web wire; b) forming or applying an intermediate web layer formed from a second pulp suspension comprising at least 50% by dry weight of MFC having an SR value in the range of 80-100 on the bottom web layer; c) applying a top web layer formed from a third pulp suspension comprising at least 50% by dry weight of cellulose based fibrous material having an SR (Schopper-Riegler) value in the range of 18-75 on the intermediate web layer to form a multilayer web; and d) dewatering, and optionally drying, the formed multilayer web to obtain a multilayer film comprising MFC.