Molded pulp article and processes of making same

Abstract

A three dimensional molded object comprising a mixture of cellulose fibers and microfibrillated cellulose, and optionally one or more inorganic particulate material, wherein the microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 50 wt. % on a dry weight basis of the total dry mass of the mixture of cellulose fibres and microfibrillated cellulose, and optionally one or more inorganic particulate material; wherein the coarsely microfibrillated cellulose comprises less than about 90 wt. % fines and/or less than 75% fines A, and a length-weighted median length Lc(w) of greater than 0.3 mm, as measured by fibre image analyzer, and wherein the microfibrillated cellulose optionally has a fibre steepness of about 20 to about 50, as measured by Malvern Mastersizer.

What is claimed is: 
     
         1 . A three-dimensional molded object comprising a mixture of cellulose fibers and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material, wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 50 wt. % on a dry weight basis of the total dry mass of the mixture of cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material; wherein the coarsely microfibrillated cellulose comprises less than about 90 wt. % fines and/or less than 75% fines A, and a length-weighted median length Lc(w) of greater than 0.3 mm, as measured by Valmet Fibre Image Analyzer, and wherein the coarsely fibrillated microfibrillated cellulose optionally has a fibre steepness of about 20 to about 50, as measured by Malvern Mastersizer. 
     
     
         2 . The molded object according to  claim 1 , wherein the coarsely fibrillated microfibrillated cellulose has a fibre steepness of about 20 to about 50. 
     
     
         3 . The molded object according to  claim 1 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 25 wt. %. 
     
     
         4 . The molded object according to  claim 1 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 15 wt. %. 
     
     
         5 . The molded object according to  claim 1 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 10 wt. %. 
     
     
         6 . The molded object according to  claim 1 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 5 wt. %. 
     
     
         7 . The molded object according to  claim 1 , wherein, the coarsely fibrillated microfibrillated cellulose is obtained from a pulp selected from the group consisting of a chemical pulp, a chemithermomechanical pulp, a mechanical pulp, a thermomechanical pulp, a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         8 . The molded object according to  claim 1 , wherein, the coarsely fibrillated microfibrillated cellulose is obtained from a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         9 . The molded object according to  claim 1 , wherein, the cellulose fibres are obtained from a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         10 . The molded object according to  claim 1 , wherein, the cellulose fibres are obtained from a pulp selected from the group consisting of a chemical pulp, a chemithermomechanical pulp, a mechanical pulp, a thermomechanical pulp, a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         11 . The molded object according to  claim 1 , wherein both the cellulose fibres and microfibrillated cellulose are obtained from a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         12 . The molded object according to  claim 1 , wherein the molded object comprises one or more inorganic particulate material. 
     
     
         13 . The molded object according to  claim 1 , wherein the one or more inorganic particulate material is calcium carbonate or kaolin, or mixtures thereof. 
     
     
         14 . The molded object according to  claim 1 , wherein the one or more inorganic particulate material comprises a platy mineral, kaolin and/or talc. 
     
     
         15 . The molded object according to  claim 13 , wherein the calcium carbonate is ground calcium carbonate, precipitated calcium carbonate, or mixtures thereof. 
     
     
         16 . The molded object according to  claim 15 , wherein the calcium carbonate is precipitated calcium carbonate. 
     
     
         17 . The molded article according to  claim 15 , where in the calcium carbonate is ground calcium carbonate. 
     
     
         18 . The molded object according to  claim 17 , wherein the ground calcium carbonate is marble, chalk, limestone and mixtures thereof. 
     
     
         19 . The molded object according to  claim 12 , wherein the inorganic particulate material is ground calcium carbonate and precipitated calcium carbonate. 
     
     
         20 . The molded object according to  claim 12 , wherein the inorganic particulate material is selected from the group consisting of an alkaline earth metal carbonate or sulphate, a bentonite, a hydrous kandite clay, a halloysite, a ball clay, an anhydrous (calcined) kandite clay, a metakaolin, a fully calcined kaolin, a talc, a mica, a perlite, a sepiolite, a huntite, a diatomite, a magnesite, a silicate, a diatomaceous earth, a brucite, an aluminum trihydrate, and combinations thereof. 
     
     
         21 . A method for producing a three-dimensional molded object comprising cellulose fibers and coarsely fibrillated microfibrillated cellulose, comprising the steps of:
 providing a mixture comprising cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material, wherein the mixture comprises microfibrillated cellulose in an amount of about 0.5 wt. % to about 50 wt. % on a dry weight basis of the total dry mass of the mixture of cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material; wherein the coarsely microfibrillated cellulose comprises less than about 90 wt. % fines and/or less than 75% fines A, and a length-weighted median length Lc(w) of greater than 0.3 mm, as measured by Valmet Fibre Image Analyzer, and wherein the coarsely fibrillated microfibrillated cellulose optionally has a fibre steepness of about 20 to about 50, as measured by Malvern Mastersizer;   forming a three-dimensional molded object from the mixture; and   drying the three-dimensional molded object.   
     
     
         22 . The method according to  claim 21 , wherein the coarsely fibrillated microfibrillated cellulose has a fibre steepness of about 20 to about 50. 
     
     
         23 . The method according to  claim 21 , wherein the forming step is a wet forming step. 
     
     
         24 . The method according to  claim 21 , wherein the forming step is a dry forming step. 
     
     
         25 . The method according to  claim 21 , further comprising the steps of:
 providing a porous mold having a three-dimensional shape comprising a forming portion having an inside and an outside portion;   bringing the forming portion into contact with the mixture comprising cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material;   applying a vacuum to the inside portion of the forming section to form a wet layer of cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material, on the outside portion of the forming section, thereby forming a three dimensional molded object, wherein the wet layer of cellulose fibres and coarsely fibrillated microfibrillated cellulose and optionally one or more inorganic particulate material is between about 100 to 5,000 gsm in dry weight on a dry weight basis of the total dry mass of the mixture of cellulose fibres and coarsely fibrillated microfibrillated cellulose, and optionally one or more inorganic particulate material;   transferring the molded object to a drying conveyor and drying the three-dimensional molded object; optionally transferring the three-dimensional molded object to a second inverse shaped mold and pressing the three-dimensional molded prior to oven drying.   
     
     
         26 . The method according to  claim 21 , wherein the cellulose fibres are obtained from virgin pulp, recycled paper or old corrugated cardboard, or a combination thereof. 
     
     
         27 . The method according to  claim 21 , wherein the cellulose fibres are obtained from virgin pulp. 
     
     
         28 . The method according to  claim 21 , wherein the cellulose fibres are obtained from recycled pulp. 
     
     
         29 . The method according to  claim 28 , wherein the recycled pulp is obtained from old, corrugated cardboard. 
     
     
         30 . The method according to  claim 21 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 25 wt. %. 
     
     
         31 . The method according to  claim 21 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 15 wt. %. 
     
     
         32 . The method according to  claim 21 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 10 wt. %. 
     
     
         33 . The method according to  claim 21 , wherein the coarsely fibrillated microfibrillated cellulose is present in an amount of about 0.5 wt. % to about 5 wt. %. 
     
     
         34 . The method according to  claim 21 , wherein, the coarsely fibrillated microfibrillated cellulose is obtained from a pulp selected from the group consisting of a chemical pulp, a chemithermomechanical pulp, a mechanical pulp, a thermomechanical pulp, a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         35 . The method according to  claim 21 , wherein, the coarsely fibrillated microfibrillated cellulose is obtained from a pulp selected from the group consisting of a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         36 . The method according to  claim 21 , wherein, the cellulose fibres are obtained from a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         37 . The method according to  claim 21 , wherein, the cellulose fibres are obtained from a pulp selected from the group consisting of a chemical pulp, a chemithermomechanical pulp, a mechanical pulp, a thermomechanical pulp, a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         38 . The method according to  claim 21 , wherein both the cellulose fibres and coarsely fibrillated microfibrillated cellulose are obtained from a recycled pulp, a paper broke pulp, a papermill waste stream, waste from a papermill, and combinations thereof. 
     
     
         39 . The method according to  claim 21 , wherein the molded object comprises one or more inorganic particulate material. 
     
     
         40 . The method according to  claim 39 , wherein the one or more inorganic particulate material is calcium carbonate or kaolin, or mixtures thereof. 
     
     
         41 . The method according to  claim 39 , wherein the one or more inorganic particulate material comprises a platy mineral, kaolin and/or talc. 
     
     
         42 . The method according to  claim 40 , wherein the calcium carbonate is ground calcium carbonate, precipitated calcium carbonate, or mixtures thereof. 
     
     
         43 . The method according to  claim 40 , wherein the calcium carbonate is precipitated calcium carbonate. 
     
     
         44 . The method according to  claim 40 , wherein the calcium carbonate is ground calcium carbonate. 
     
     
         45 . The method according to  claim 44 , wherein the ground calcium carbonate is marble, chalk, limestone, and mixtures thereof. 
     
     
         46 . The method according to  claim 39 , wherein the inorganic particulate material is ground calcium carbonate and precipitated calcium carbonate. 
     
     
         47 . The method according to  claim 39 , wherein the inorganic particulate material is selected from the group consisting of an alkaline earth metal carbonate or sulphate, a bentonite, a hydrous kandite clay, a kaolin, a halloysite, a ball clay, an anhydrous calcined kandite clay, a metakaolin, a fully calcined kaolin, a talc, a mica, a perlite, a sepiolite, a huntite, a diatomite, a magnesite, a silicate, a diatomaceous earth, a brucite, an aluminum trihydrate, and combinations thereof. 
     
     
         48 . A three-dimensional packaging container, blister pack, egg carton, bottle, container or food tray comprising the three-dimensional article according to  claim 1 . 
     
     
         49 . A three-dimensional packaging container, blister pack, egg carton, bottle, container or food tray obtained by a process according to  claim 21 . 
     
     
         50 . (canceled)