The present invention provides a method and system for measuring disintegration of a fibrous product. The method comprises disintegration of a sample of the fibrous product in an aqueous solution, optionally promoted by mechanical energy, passing the aqueous solution through a screen to obtain a permeate and retained fraction on the screen, and analyzing at least one parameter from the permeate for example by a gravimetric analysis, an optical analysis, an electrochemical analysis, a volumetric analysis, or combination thereof. Advantages include adjustability, speed, and high correlation with actual flushability or repulpability of the fibrous product, and utility in a process for manufacturing a fibrous sheet exhibiting controlled disintegration, such as a flushable or repulpable fibrous sheet.

The present invention involves an environmentally friendly process and apparatus for the delignification of lignin-containing materials, such as cardboard newspaper or agricultural or tree pruning wastes. This process produces cellulose using low temperatures and low concentrations of hydrogen peroxide. It can be performed using a column fitted with a semipermeable gasket that pressurizes the column by retaining oxygen released by action of the hydrogen peroxide on a lignin-containing material.

A method is provided for recovering pulp fibers having little damage from a used absorbent article which includes a water permeable front sheet, a water impermeable back sheet and an absorbent body that contains pulp fibers and a superabsorbent polymer. At least one opening with a circle equivalent diameter of 5-45 mm, or 10-45 mm cut, is made in the front sheet and/or the back sheet of the used absorbent article, which is then agitated in an organic acid aqueous solution with a pH of less than or equal to 2.5, and the superabsorbent polymer is deactivated and the pulp fibers and superabsorbent polymer are discharged from the used absorbent article through the opening or cut.

A method is provided which, by a simple process, separates and recovers pulp fibers from a used absorbent article that contains pulp fibers and a superabsorbent polymer. A used absorbent article is treated with an aqueous solution that contains greater than or equal to 0.05 mass % of at least one kind of terpene selected from the group comprising terpene hydrocarbons, terpene aldehydes, and terpene ketones and that contains a deactivating agent that can deactivate the superabsorbent polymer; the superabsorbent polymer is deactivated, the adhesive that bonds together the constituent materials of the absorbent article is dissolved with the terpene to decompose the absorbent article, the pulp fibers are discharged to outside of the absorbent article, and the pulp fibers are separated from the absorbent article and recovered.

The purpose of the present invention is to provide a method for producing recycled pulp fibers such that articles using the recycled pulp fibers can easily achieve a uniform whiteness and users are not prone to feel psychological resistance to articles using the recycled pulp fibers. 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 multiple types of 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 the pulp fibers are bleached to form recycled pulp fibers; and a step for discharging the treatment solution (52) from a treatment solution discharge port (33), wherein the recycled pulp fibers have a 0-10 YI with respect to a standard white plate.

A method is provided which, by a simple process, separates and recovers pulp fibers from a used absorbent article that contains pulp fibers and a superabsorbent polymer. A used absorbent article is treated with an aqueous solution that contains greater than or equal to 0.05 mass % of at least one kind of terpene selected from the group comprising terpene hydrocarbons, terpene aldehydes, and terpene ketones and that contains a deactivating agent that can deactivate the superabsorbent polymer; the superabsorbent polymer is deactivated, the adhesive that bonds together the constituent materials of the absorbent article is dissolved with the terpene to decompose the absorbent article, the pulp fibers are discharged to outside of the absorbent article, and the pulp fibers are separated from the absorbent article and recovered.

Pulp fiber containing little ash is effectively recovered from a used sanitary product containing the pulp fiber and a polymer absorbent. The method according to the present invention comprises: a step for treating the used sanitary product with an ozone-containing gas and thus decomposing and removing at least a portion of the polymer absorbent in the used sanitary product; and a step for stirring the used sanitary product, that has been treated with the ozone-containing gas, in water or an aqueous solution containing an antiseptic and thus decomposing the used sanitary product into constituents. If required, the method may further comprise a step for separating the pulp fiber from the decomposition product obtained by the decomposition step.

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 %.

A recycled cellulose raw material and a method for recycling a cellulose raw material from blended textile waste with high reliability and yielding high raw material quality is shown, the method comprising the steps in the given order: providing the blended textile waste containing at least one cellulose component and at least one synthetic polymer component, treating the blended textile waste in a non-oxidizing aqueous treatment medium in order to degrade the at least one synthetic polymer component, whereby the treatment is carried out at a temperature between 100? C. and 200? C., and obtaining the recycled cellulose raw material from the treated blended textile waste.

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.