A composition and process for making the composition by co-refining: fibrillated virgin cellulose fibers, waste/recycle cellulose fibers, or both; co-refined cellulose ester (CE) staple fibers having a denier per filament (DPF) of less than 3 and the weight percent of CE staple fibers is less than 30 wt. %, based on the weight of CE staple fibers and said cellulose fibers; and water. The composition can be co-refined to obtain lower Canadian standard freeness yet improved drainage and wet laid products having good tensile strength, air permeability, stiffness, burst strength, and bulk.

[Problem] To provide a contamination preventing agent composition capable of effectively preventing pitch contamination in a dry part. [Solution] The present invention relates to a contamination preventing agent composition for preventing pitch contamination in a dry part D of a papermaking process, the composition containing: a linear polysiloxane compound represented by formula (1); and a cyclic siloxane compound. [In formula (1), a substituent R.sup.1 represents, in the same molecule, a hydrogen atom, an alkyl group, a methylphenyl group, a polyether group, a higher fatty acid ester group, an amino-modified group, an epoxy-modified group, a carboxylic group, a phenol group, a mercapto group, a carbinol group, or a methacrylic group, and a repeating number n of a siloxane unit represents an integer of 20-1430.] ##STR00001##

A use of organofunctionalized mesoporous silica for the production of recycled paper; the organofunctionalized mesoporous silica comprises a base mesoporous silica having, on its surface, groups having the following general formula (I), wherein Si.sup.1 is a silicon atom of the base mesoporous silica, R.sup.1 is a C.sub.1-C.sub.5 aliphatic; R.sup.2 is chosen in the group consisting of: a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica; and R.sup.3 is chosen in the group consisting of: a hydroxyl, a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica (I). ##STR00001##

A use of organofunctionalized mesoporous silica for the production of recycled paper; the organofunctionalized mesoporous silica comprises a base mesoporous silica having, on its surface, groups having the following general formula (I), wherein Si.sup.1 is a silicon atom of the base mesoporous silica, R.sup.1 is a C.sub.1-C.sub.5 aliphatic; R.sup.2 is chosen in the group consisting of: a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica; and R.sup.3 is chosen in the group consisting of: a hydroxyl, a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica (I). ##STR00001##

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2 500 000-18 000 000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

A method for monitoring hydrophobic particles contained in a pulp suspension, includes obtaining a sample from a pulp suspension or a filtrate of the pulp suspension. A fluorescent dye is added to the sample to stain particles in the sample. The sample is fractionated to obtain at least a first fraction and a second fraction, wherein the second fraction is a fiber fraction. The method includes for the obtained fractions, fluorescence emitted by the particles in the fractions, calculating an integral of the fluorescence measured for the fractions excluding the fiber fraction, and correlating the calculated integral of the fluorescence to the amount of acetone soluble material in the pulp suspension, and optionally measuring light scattering signal of the particles in at least first and second fractions.

In some variations, OCC is screened, cleaned, deinked, and mechanically refined to generate cellulose nanofibrils. The OCC may be subjected to further chemical, physical, or thermal processing, prior to mechanical refining. For example, the OCC may be subjected to hot-water extraction, or fractionation with an acid catalyst, a solvent for lignin, and water. In certain embodiments to produce cellulose nanocrystals, OCC is exposed to AVAP® digestor conditions. The resulting pulp is optionally bleached and is mechanically refined to generate cellulose nanocrystals. In certain embodiments to produce cellulose nanofibrils, OCC is exposed to GreenBox+® digestor conditions. The resulting pulp is mechanically refined to generate cellulose nanofibrils. The site of a system to convert OCC to nanocellulose may be co-located with an existing OCC processing site. The nanocellulose line may be a bolt-on retrofit system to existing infrastructure. In other embodiments, a dedicated plant for converting OCC to nanocellulose is used.

In some variations, OCC is screened, cleaned, deinked, and mechanically refined to generate cellulose nanofibrils. The OCC may be subjected to further chemical, physical, or thermal processing, prior to mechanical refining. For example, the OCC may be subjected to hot-water extraction, or fractionation with an acid catalyst, a solvent for lignin, and water. In certain embodiments to produce cellulose nanocrystals, OCC is exposed to AVAP® digestor conditions. The resulting pulp is optionally bleached and is mechanically refined to generate cellulose nanocrystals. In certain embodiments to produce cellulose nanofibrils, OCC is exposed to GreenBox+® digestor conditions. The resulting pulp is mechanically refined to generate cellulose nanofibrils. The site of a system to convert OCC to nanocellulose may be co-located with an existing OCC processing site. The nanocellulose line may be a bolt-on retrofit system to existing infrastructure. In other embodiments, a dedicated plant for converting OCC to nanocellulose is used.

In alternative embodiments, provided herein are methods and industrial processes for generating high purity (high alpha cellulose) pulp from lignocellulosic feedstocks, comprising directly contacting a lignocellulosic feedstock with a system comprising a super critical or near-super critical fluid or mixture of fluids, whereby the partial pressure of the system provides for the alcoholysis, hydrolysis or a combination thereof of the feedstock at reduced temperatures and pressures, followed by an upgrading step wherein a low-purity cellulosic material generated in the super critical or near-super critical reaction step is treated with an alkaline solution. Also provided herein are systems and methods for producing a high purity cellulose material using reduced amounts of alkaline material.

In alternative embodiments, provided herein are methods and industrial processes for generating high purity (high alpha cellulose) pulp from lignocellulosic feedstocks, comprising directly contacting a lignocellulosic feedstock with a system comprising a super critical or near-super critical fluid or mixture of fluids, whereby the partial pressure of the system provides for the alcoholysis, hydrolysis or a combination thereof of the feedstock at reduced temperatures and pressures, followed by an upgrading step wherein a low-purity cellulosic material generated in the super critical or near-super critical reaction step is treated with an alkaline solution. Also provided herein are systems and methods for producing a high purity cellulose material using reduced amounts of alkaline material.