The present disclosure relates to a method for preparing an unbleached biomechanical pulp from straws and full utilization of by-products, which belongs to the technical field of papermaking technology and waste comprehensive utilization. In the present disclosure, straw as raw material for pulping is treated with steam, then a small amount of KOH is added, the straw is softened by hydrothermal saturation, then the temperature of the straw is adjusted, alkaline compound enzymes are added for biological treatment, and finally the straw is refined, where the prepared mechanical pulp can meet the requirements of producing unbleached packaging paper and paper-based materials. At the same time, the by-products are recycled to prepare biomass compound fertilizer, which turns solid waste into treasure and realizes the high-value full utilization of wheat straw. Therefore, it has good practical application value and broad application prospects.

A process to separate lignin from a lignocellulosic feedstock, said process comprising the steps of: providing said lignocellulosic feedstock; providing a composition comprising; an acid; a modifying agent selected from the group consisting of: sulfamic acid; imidazole; imidazole derivatives; taurine; a taurine derivative; a taurine-related compound; alkylsulfonic acid; arylsulfonic acid; triethanolamine; and combinations thereof; a peroxide salt; and a peroxide; exposing said lignocellulosic feedstock to said composition for a period of time sufficient to depolymerize substantially all of the lignin present in said lignocellulosic feedstock into lignin oligomers and lignin monomers;
wherein said process is carried out at atmospheric pressure.

A method is provided for manufacturing a polyimide fiber paper intermediate structure, which includes: a short fiber preparing step for preparing shaved short fibers of a non-thermoplastic polyimide; and an intermediate structure forming step for forming a polyimide fiber paper intermediate structure in which the short fibers are temporarily bonded using a water-soluble and/or water-insoluble thermoplastic polymer having a melting point lower than a glass transition point of a polyimide.

High permeability curly fibers with enhanced fiber strength are produced by mercerizing cellulosic fibers. The fibers have relatively high values for curl, kink level, wet tensile strength, and bulk density when compared with current fibers. The disclosed fibers can be used in a wide range of applications including paper products such as filters.

Pulps, cellulose ether products, and methods of making pulps are described.

Methods of forming crosslinked cellulose include mixing a crosslinking agent with cellulose mat fiber fragments composed of hydrogen-bonded cellulose fibers and having a solids content of about 45-95% to form a substantially homogenous mixture of non-crosslinked, individualized cellulose fibers, drying the resulting mixture to 85-100% solids, then curing the dried mixture under conditions effective to crosslink the cellulose fibers. Some of such methods may include fragmenting a cellulose fiber mat to form the mat fragments. Systems include a mixing unit (such as a high-consistency mixer) configured to form, from the mat fragments and a crosslinking agent, a substantially homogenous mixture of non-crosslinked, individualized cellulose fibers and crosslinking agent, at ambient conditions, a drying unit to dry the substantially homogenous mixture to a consistency of 85-100%, and a curing unit and to cure the crosslinking agent to form dried and cured crosslinked cellulose fibers.

The present invention relates to a method for dewatering a web comprising microfibrillated cellulose, wherein the method comprises the steps of: providing a suspension comprising between 50 wt-% to 100 wt-% of microfibrillated cellulose based on total dry weight, forming a fibrous web of said suspension on a support wherein said web has a dry content of 1-25% by weight, applying a dewatering felt into direct contact with the fibrous web, conducting said fibrous web, arranged between said dewatering felt and said support, through at least one shoe press equipment, drying the dewatered web to form a film which film has an Oxygen Transmission Rate (OTR) value (23° C., 50% RH) below 100 cc/m.sup.2/24 h according to ASTM D-3985.

Disclosed herein are treated pulp sheets comprising cellulose pulp fibers treated with a densifying agent and having a relatively low moisture content. In certain embodiments, the treated pulp sheets are used to produce fiberized pulp having an unexpectedly low knot content, while maintaining density and softness properties usually associated with similarly treated pulp that is fiberized at higher moisture content. Methods of making fiberized pulp from the treated pulp sheets, as well as products comprising the treated pulp sheets or fiberized pulp from the treated pulp sheets, are also provided.

The present invention relates to a modified cellulosic fiber that comprises anionic moieties in an amount of more than 0.25 mol/kg of dry fiber and has applied thereon a polymeric modifying agent in an amount of from 0.5 wt. % to 5.0 wt. %, based on dry fiber, the polymeric modifying agent comprising cationic moieties with a charge of at least 1.5 meq per gram of polymer and the molar ratio of anionic moieties to cationic moieties contained in the fiber is in the range of from 1:1 to 25:1. The fiber according to the present invention is characterized in that the anionic moieties are incorporated in the fiber and are from carboxymethylcellulose, and that the polymeric modifying agent comprising cationic moieties is selected from the group consisting of polydiallyldimethylammonium chloride (poly-DADMAC), poly(acrylamide-co-diallyldimethylammonium chloride) (PAM-DADMAC) and mixtures thereof. The invention furthermore relates to a nonwoven product or fabric comprising the modified cellulosic fiber.

The present disclosure relates to the use of alkoxylated fatty amido alcohols in the process to make viscose wherein cellulose is reacted with lye and the lye strength is from about 8 to about 20% by weight of NaOH, based on the weight of water in the reaction mixture. The use as a reaction improvement additive improves the reaction rate between the cellulose and the lye. The use also improves the reaction between alkali-cellulose and CS.sub.2. The present disclosure also relates to solid cellulose that is treated with one or more ethoxylated fatty amido alcohols and which is suitable for use in the claimed process.