Natural bamboo is chemically treated to remove at least some lignin therefrom. As a result, the bamboo becomes more porous and less rigid, while otherwise retaining the aligned microstructure of bamboo fibers and constituent cellulose nanofibers. In some embodiments, the treated bamboo can then be pressed such that the lumina therein at least partially collapse, thereby improving the strength and toughness of the bamboo among other properties. In some embodiments, the treated bamboo can be infiltrated with a polymer or polymer precursor, and/or have non-native particles added to surfaces thereof to tailor properties of the resulting bamboo structure. By further modifying, manipulating, or machining the treated bamboo, it can be adapted to various applications.

The present invention provides a composition and process for preparing a depolymered paper product from polymer-coated paper waste, comprising the steps of treating shredded polymer-coated paper waste with a polymer removing composition comprising a mixture of a solvent component, a surfactant component, and an acidic component.

The present invention concerns a facility for cleaning cigarette butts, including a treatment tank configured to treat the cigarette butts in order to extract therefrom fibres to be depolluted, and depollution means configured to depollute the fibres by placing them in contact with a fluid in the supercritical state, referred to as supercritical fluid.

The purpose of the present invention is to provide a method which is for producing pulp fibers for cellulose nanofiberization from pulp fibers of used sanitary products, and which can produce pulp fibers for cellulose nanofiberization that have low lignin content and a low distribution thereof and that have excellent cellulose nanofiberization properties. This method is described below. The method is characterized by involving: a step for supplying, from a mixed solution supply port (32) to a treatment tank (31), a mixed solution (51) which contains superabsorbent polymers and pulp fibers derived from used sanitary products; a step for supplying an ozone-containing gas (53) from an ozone-containing gas supply port (43) to a treatment solution (52) inside of the treatment tank (31); a step in which, by raising the ozone-containing gas (53) while lowering the superabsorbent polymers and pulp fibers in the treatment tank (31), the ozone-containing gas (53) is brought into contact with the superabsorbent polymers and the pulp fibers, and pulp fibers for cellulose nanofiberization are formed from the pulp fibers; and a step for discharging the treatment solution (52) from a treatment solution discharge port (33), wherein the pulp fibers for cellulose nanofiberization have a lignin content of less than or equal to 0.1 mass %.

The present invention provides a novel method and composition for enhancing the efficiency of starch adsorption (i.e., starch trapping) from starch-containing furnishes comprising high content of recycled fibers for use in paper making processes such as pulp, paper, or board production. A novel polymer coagulation system is disclosed in which two quick inversion cationic emulsion polymers (starch trapping polymers A and B) are co-mixed at optimal blend ratios to meet specific recycled fiber and process water requirements for different recycled fiber plants and added to furnishes prior to formation of paper or board in a paper machine. Co-mixed solutions of starch trapping polymers A and B provide synergistic enhancements in (i) starch trapping efficiency and (ii) starch retention in the produced paper or board over equivalent dosage levels of singly administered polymer A, polymer B, or conventional starch trapping products, without over-flocculation or formation of stickies.

A method for manufacturing bleached pulp from a feedstock that includes recycled paper. The method includes steps of: (1) impregnating the feedstock with cooking liquor to yield an impregnated material having a liquor-to-fiber mass ratio of at most about 4:1; (2) cooking the impregnated material to remove at least a portion of the lignin within the impregnated material, thereby yielding a cooked pulp; and (3) bleaching the cooked pulp.

A method for controlling the deposition of stickies in pulping and papermaking processes comprises adding to fibre pulp or stock an additive comprising an organo-modified siloxane comprising units of the formula: [R.sup.1.sub.aZ.sub.bSiO.sub.(4-a-b)/2].sub.n in which each R.sup.1 is independently selected from a hydrogen atom, an alkyl, aryl, alkenyl, aralkyl, alkaryl, alkoxy, alkanoyloxy, hydroxyl, ester or ether group, and each Z is independently selected from an alkyl group substituted with an amine, amide, carboxyl, ester, or epoxy group, or preferably at least one or more groups —R.sup.2—(OC.sub.pH.sub.2p).sub.q(OC.sub.rH.sub.2r).sub.S—R.sup.3; wherein n is an integer greater than 1; a and b are independently 0, 1, 2 or 3; R.sup.2 is an alkylene group or a direct bond; R.sup.3 is a group as defined for R.sup.1 or Z above; p and r are independently an integer from 1 to 6; q and s are independently 0 or an integer such that 1≦q+s≦400; and wherein each molecule of the organo-modified siloxane contains at least one group Z. The organo-modified siloxane is preferably a hydroxyl- or alkyl-endcapped linear polydimethylsiloxane, in which 5 to 18 mole percent of silicon atoms are substituted by Z groups of the formula —R.sup.2—(OC.sub.pH.sub.2p).sub.q(OC.sub.rH.sub.2r).sub.s—R.sup.3, in which p is 2, r is 3 and q and s are independently 10 to 20, R.sup.2 is an alkylene group having from 1 to 6 carbon atoms or a direct bond, and R.sup.3 is a hydrogen atom or a hydroxyl, alkoxy, ester or ether group.

Processes for converting lignocellulose to feedstock and downstream products are disclosed. The processes may include acid treatment of lignocellulose to produce a fermentation feedstock. In various instances, the processes include recovery or recycling of acid, such as recovery of hydrochloric acid from concentrated and/or dilute streams. Downstream products may include acrylic acid-based products such as diapers, paper and paper-based products, ethanol, biofuels such as biodiesel and fuel additives, and detergents.

A high efficiency bleaching method for cellulosic pulp includes: (a) providing a charge of aqueous cellulosic pulp to a bleaching vessel at a consistency of from 10% to 30% along with a peroxy bleaching agent and an alkaline agent effective to adjust pH of the charge to 9.5 to 12.5; and (b) bleaching the aqueous cellulosic pulp in the bleaching vessel while maintaining a bleaching temperature of from 110° F. (43° C.) to 135° F. (57° C.) and a pH of the charge from 9.5 to 12.5 for an extended bleaching retention time. The bleaching method is advantageously used to bleach low brightness recycle pulp, and/or as part of a multistage process with bleaching stages of lesser duration, and/or as a high peroxy efficiency, low dose bleaching process or in connection with concurrently storing and bleaching pulp.

A method for the production of paper products, such as paper and cardboard, by recycling cellulose-based raw materials containing starch. The method includes the steps of pulping in water cellulose-based raw materials containing starch, particularly recycled paper products, obtaining a pulped mass; adding to the pulped mass of the previous step under agitation a mineral acid in a quantity that is suitable to obtain a pH of the pulped mass not lower than 4, and obtaining a pulped mass treated with acid. The method further includes the step of subjecting the pulped mass treated with acid obtained in the second step, optionally treated with other chemical additives, in succession, to filtration, pressing and drying, and obtaining a paper product. Paper products obtainable by this method are also related.