A method and apparatus for controlling a cellulosic pulp process for producing a pulp product having a desired pulp property is disclosed. The method involves illuminating an in-process portion of pulp using a first wavelength of light, and receiving a scattered light spectrum from the illuminated portion of pulp, the scattered light spectrum including spectral components that have been shifted in wavelength through interaction with a constituent of the illuminated portion of pulp. The method also involves filtering the scattered light spectrum to separate the spectral components, and identifying spectral features in the filtered scattered light spectrum that correspond to the pulp property. The method further involves generating a control signal for controlling the pulp process based on variations in the identified spectral features to cause the pulp property to fall within a desired range.

A method for making a specialty fiber by activating pulp in an alkaline aqueous medium, then reacting it a water-soluble, multi-functional reagent able to bridge neighboring cellulose chain within a single fiber. The resultant specialty cellulose fibers have high intrinsic viscosity and may be used to make cellulose ethers, cellulose acetate, and viscose.

A method for preparing an aqueous suspension may include providing a fibrous substrate comprising cellulose having a Canadian Standard freeness equal to or less than 450 cm.sup.3, and microfibrillating the fibrous substrate in an aqueous environment by grinding in the presence of a grinding medium consisting essentially of mullite. The grinding may be carried out in the absence of grindable inorganic particulate material. The grinding medium may be present in an amount of at least about 10% by volume of the aqueous environment. The microfibrillated cellulose may have a fibre steepness of from about 20 to about 50.

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.

A super strong and tough densified wood structure is formed by subjecting a cellulose-based natural wood material to a chemical treatment that partially removes lignin therefrom. The treated wood retains lumina of the natural wood, with cellulose nanofibers of cell walls being aligned. The treated wood is then pressed in a direction crossing the direction in which the lumina extend, such that the lumina collapse and any residual fluid within the wood is removed. As a result, the cell walls become entangled and hydrogen bonds are formed between adjacent cellulose nanofibers, thereby improving the strength and toughness of the wood among other mechanical properties. By further modifying, manipulating, or machining the densified wood, it can be adapted to various applications.

A process for preparing a cellulosic sponge includes the steps of treating an aqueous suspension of cellulose fibers with periodate; adjusting the pH of the resulting dialdehyde cellulose fibers suspension to a value between 2.5 to 5.5; freezing the suspension obtained and thawing the three dimensional structure to render the cellulosic sponge. The process may further include a step of drying to render a cellulosic foam. Both the new sponge and the new foam may also be further chemically modified obtaining a broad variety of derivatives with tailored properties which are useful in many different applications.

A method of producing nanocellulose includes defibrillating cellulosic raw material by oxidation with an oxidant such as NaClO or H202 and sonication in the presence of a swelling agent. The nanocellusose produced by the method can be used in a method of recycling cellulosic material such as paper, card, cardboard or wood to produce recycled paper.

The present invention addresses the problem of efficiently manufacturing a recycled pulp from a used sanitary article, said recycled pulp being reusable for sanitary articles and having an ash content and antibacterial properties both meeting the standards for sanitary articles. A method for manufacturing a recycled pulp reusable for sanitary articles by recovering a pulp fiber from a used sanitary article that contains the pulp fiber and a high water-absorbing polymer, said method comprising an ozone treatment step for immersing the used sanitary article or pulp fiber in an ozone-containing aqueous solution and thus disintegrating the high water-absorbing polymer contained in the used sanitary article or sticking to the pulp fiber, characterized in that the used sanitary article or pulp fiber is treated with a cationic antibacterial agent before, after or together with the ozone treatment step.

The present invention addresses the problem of efficiently manufacturing a recycled pulp from a used sanitary article, said recycled pulp being reusable for sanitary articles and having an ash content and antibacterial properties both meeting the standards for sanitary articles. A method for manufacturing a recycled pulp reusable for sanitary articles by recovering a pulp fiber from a used sanitary article that contains the pulp fiber and a high water-absorbing polymer, said method comprising an ozone treatment step for immersing the used sanitary article or pulp fiber in an ozone-containing aqueous solution and thus disintegrating the high water-absorbing polymer contained in the used sanitary article or sticking to the pulp fiber, characterized in that the used sanitary article or pulp fiber is treated with a cationic antibacterial agent before, after or together with the ozone treatment step.

Methods of improving the re-dispersibility of dried or at least partially dried microfibrillated cellulose, methods of re-dispersing dried or at least partially dried microfibrillated cellulose, compositions comprising re-dispersed microfibrillated cellulose and the use of re-dispersed microfibrillated cellulose in an article, product or composition; and methods of improving the physical and/or mechanical properties of re-dispersed dried or partially dried microfibrillated cellulose.