A process for producing refined cotton with a high polymerization degree includes: a. selection of material; b. impurity removal; c. impregnation; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide in equal proportion to form a cooking compound adjuvant with a mass concentration of 0.2-0.5%, putting the cookingcompound adjuvant into a spherical digester together with the cotton linter subjected to the impregnation treatment, heating to 70 C, stopping heating, and subjecting to idling pretreatment for 40-60 min; e. cooking; f. cooling of the spherical digester; g. formulating a chlorine dioxide bleaching stabilization solution; h. a first stage of bleaching; I. alkali treatment; J. a second stage of bleaching; K. dechlorination; and 1. rolling and drying by baking.

The invention relates to a method for pitch control and/or removal during bleaching of cellulosic fibres. Cellulosic fibres are obtained from a pulping process and formed into an aqueous cellulosic fibre suspension, and bleaching of the cellulosic fibre suspension is performed in a bleaching process comprising at least one acidic stage, where pH of the cellulosic fibre suspension is <6. A pitch control agent is added to the cellulosic fibre suspension before the acidic stage, wherein the pitch control agent comprises at least one cationic polymer comprising cationic functional groups which are hydrolysed at pH 9.0

According to an example aspect of the present invention, there is provided a method of replacing with sodium make-up chemicals sodium losses caused by outflows in a pulp mill which employs a kraft process for producing cellulosic pulp, wherein the pulp mill includes a unit for conversion of sulphurous compounds, which is fed with sulphurous substances of the kraft process to convert said sulphurous substances into oxidized sulphurous compounds, said method comprising using sodium sulphate possibly together with other sodium salts as the main make-up chemical, to achieve an essentially sodium hydroxide free feed of sodium make-up chemicals, and at least a part of the sulphur contained in the sodium sulphate make-up chemical being used for producing oxidized sulphurous compounds in said unit for conversion of sulphurous compounds.

Methods for isolating cellulose nanocrystals (CNCs) from the plant Miscanthus Giganteus (MxG). Impressive yields are obtained through a combination of processing steps including base hydrolysis, bleaching and acid hydrolysis. MxG-CNCs are produced having high aspect ratios, are biorenewable and can be used for a wide range of applications such as nanofillers in composites. MxG-CNC-containing composites are also disclosed.

Cellulose nanocrystals (CNCs) from the plant Miscanthus Giganteus (MxG) and a matrix material are present in a composite composition. Impressive yields of MxG-CNCs are obtained through a combination of processing steps including base hydrolysis, bleaching and acid hydrolysis. MxG-CNCs are produced having high aspect ratios, are biorenewable and can be used for a wide range of applications such as nanofillers in composites.

A pulp fiber with an enhanced carboxyl content resulting in improved antimicrobial, anti-yellowing and absorptive properties. Methods for making the kraft pulp fiber and products made from it are also described.

A pulp fiber with an enhanced carboxyl content resulting in improved antimicrobial, anti-yellowing and absorptive properties is described. Methods for making the kraft pulp fiber and products made from it are also described.

A process for producing refined cotton with a high polymerization degree includes: a. selection of material; b. impurity removal; c. impregnation; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide in equal proportion to form a cooking compound adjuvant with a mass concentration of 0.2-0.5%, putting the cooking compound adjuvant into a spherical digester together with the cotton linter subjected to the impregnation treatment, heating to 70 C, stopping heating, and subjecting to idling pretreatment for 40-60 min; e. cooking; f. cooling of the spherical digester; g. formulating a chlorine dioxide bleaching stabilization solution; h. a first stage of bleaching; I. alkali treatment; J. a second stage of bleaching; K. dechlorination; and l. rolling and drying by baking.

A bleaching apparatus comprises a measurement chamber has a first substance, the amount of the first substance in the measurement chamber being known. A dosing unit inputs a second substance to the measurement chamber for causing a chemical reaction between the first substance and the second substance, one of the first substance and the second substance being chlorine dioxide and another of the first substance and the second substance being filtered sample from pulp slurry of a pulp process. At least one sensor performs detection of a property known to depend on the chemical reaction between the first substance and the second substance as a function of time. A data processing unit determines chemical demand of chlorine dioxide for washing loss in a bleaching sub-process on the basis of at least one value in the detected property within a known period of time after the input of the second substance.

A pulp fiber with an enhanced carboxyl content resulting in improved antimicrobial, anti-yellowing and absorptive properties. Methods for making the kraft pulp fiber and products made from it are also described.