# US 9,518,364 B2 · Wet laid sheet material of a microfibrillated material composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,364 B2 - Document ID: US9518364B2 - Status: Granted - Kind: B2 - Application number: 14/651,737 - Filed: 2013-12-11 - Published: 2015-11-05 - Granted: 2016-12-13 - Earliest claimed: 2012-12-14 - Assignees: Stora Enso OYJ - Applicants: Stora Enso OYJ - Inventors: Isto Heiskanen; Nina Ruhoniemi; Vesa Lepisto; Jouni Tuomela; Susanna Tapio; Toni Jurvanen; Petri Suhonen - Web page: https://patentgrep.com/patent/US9518364B2 ## CPC - D21H 27/10: Packing paper (packaging materials of special type or form B65D65/38) - A47L 13/16: Cloths; Pads; Sponges (metal scraping sponges A47L13/07) - D21F 11/00: Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines - D21H 11/18: Highly hydrated, swollen or fibrillatable fibres - D21H 17/675: {Oxides, hydroxides or carbonates} - D21H 21/14: characterised by function or properties in or on the paper (D21H19/66, D21H27/02 take precedence) - D21H 27/002: {Tissue paper; Absorbent paper (D21H21/22, D21H27/02, D21H27/20 take precedence; toilet paper A47K10/00; absorbent pads for physiological fluids A61L15/16; making on paper-making machines D21F11/00)} - D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR - A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08) - D21F: PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON ## Abstract A wet laid sheet material formed from a fibrous web, characterized in that the initial fibrous web contains >50% a calculated dry microfibrillated material composition by weight of the total fiber material content in the web, wherein the fibrillated material composition has a SR value of >70; and in that the moisture content in the sheet material is >30 wt.-%. ## Claims ### Claim 1 A wet laid sheet material comprising a fibrous web that contains >50% calculated as a dry microfibrillated material composition by weight of the total fiber material content in the web, wherein the microfibrillated material composition has a SR value of >70; and wherein the moisture content in the sheet material is >30 wt.-%. ### Claim 2 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein the moisture content is >40 wt.-%. ### Claim 3 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein the initial web contains >60% of calculated dry microfibrillated material composition by weight of the total fiber material content in the web. ### Claim 4 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein the microfibrillated material composition comprises a microfibrillated polysaccharide. ### Claim 5 (depends on 4) The wet laid sheet as claimed in claim 4, wherein at least a portion of the microfibrillated material composition consists of a microfibrilliated polysaccharide or a microfibrillated cellulose, having a fiber length in the range of 200 to 10,000 nm. ### Claim 6 (depends on 1) The wet laid sheet as claimed in claim 1, wherein the microfibrillated material composition comprises microfibrillated cellulose. ### Claim 7 (depends on 6) The wet laid sheet as claimed in claim 6, wherein the microfibrillated cellulose is a never dried type of microfibrillated cellulose. ### Claim 8 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein the sheet is formed in a paper making machine with reduced drying. ### Claim 9 (depends on 8) The wet laid sheet material as claimed in claim 8, wherein the web or sheet is formed in a paper making machine with substantially no drying. ### Claim 10 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein at least one surface active agent or polymer has been added to the initial wet web. ### Claim 11 (depends on 1) The wet laid sheet material as claimed in claim 1, wherein an alkaline earth carbonate or precursor thereof is added into the web, such that the wet laid sheet material comprises microfibrillated cellulose and said alkaline earth carbonate. ### Claim 12 (depends on 11) The wet laid sheet material as claimed in claim 11, wherein the alkaline earth carbonate is a calcium carbonate and wherein the sheet comprises >30 wt.-% calcium carbonate. ### Claim 13 A method of forming a wet laid sheet material from a wet fibrous web in a paper machine, wherein an initial wet fibrous web contains >65% dry microfibrillated material composition by weight of the total fiber material content in the web, wherein the microfibrillated material composition has an SR value of >70, and wherein the moisture content in the sheet material is >30%, the method comprising the steps of: i) providing a stock suspension containing >65% dry microfibrillated material composition by weight of the total fiber material content in the suspension, in a head box of the paper machine; ii) supplying said stock suspension onto a first wire in a forming section of the paper machine in such a way that the initial wet web is formed; and iii) wet pressing said wet web in a press section of the paper machine, thereby forming said wet laid sheet material. ### Claim 14 (depends on 13) The method as claimed in claim 13, wherein the initial wet fibrous web contains >80% dry microfibrillated material composition by weight of the total fiber material content in the web, and wherein step i) comprises providing a stock suspension containing the corresponding amount of dry microfibrillated material composition by weight of the total fiber material content in the suspension. ### Claim 15 (depends on 13) The method as claimed in claim 13, wherein the moisture content in the sheet material is >40%. ### Claim 16 (depends on 13) The method as claimed in claim 13, wherein the microfibrillated material composition comprises microfibrillated polysaccharide. ### Claim 17 (depends on 16) The method as claimed in claim 16, wherein at least a portion of the microfibrillated material composition consists of a microfibrillated polysaccharide or a microfibrillated cellulose, having a fiber length in the range of 200 to 10,000 nm. ### Claim 18 (depends on 13) The method as claimed in claim 13, wherein the microfibrillated material composition comprises microfibrillated cellulose. ### Claim 19 (depends on 13) The method as claimed in claim 13, wherein the microfibrillated cellulose is a never dried type of microfibrillated cellulose. ### Claim 20 (depends on 13) The method as claimed in claim 13, further comprising a step of running said wet web or sheet through a drying section of the paper machine with reduced or no drying. ### Claim 21 (depends on 13) The method as claimed in claim 13, wherein an alkaline earth carbonate or at least one precursor thereof is added to said stock suspension or to said wet web, in the forming section of the paper machine. ### Claim 22 (depends on 13) The method as claimed in claim 13, further comprising a step of providing surface active agents or polymers to said wet web in step i), or by applying said surface active agents or polymers onto said wet web in step ii). ### Claim 23 (depends on 13) The method as claimed in claim 13, wherein in step i) the temperature in the head box is >50° C. ### Claim 24 (depends on 13) A wet laid sheet material obtainable by the method as claimed in claim 13.