METHOD FOR EVALUATING DEGREE OF CLEANLINESS OF RECYCLED MATERIAL， METHOD FOR MANUFACTURING RECYCLED MATERIAL， RECYCLED PULP FIBER， AND METHOD FOR MANUFACTURING RECYCLED PULP FIBER

The objective of the present disclosure is to provide a method for easily evaluating the degree of cleanliness of recycled material derived from used sanitary products. The evaluation method according to the present disclosure has the following configuration. This method for evaluating a degree of cleanliness of recycled material derived from used sanitary products includes: a preparation step of preparing a dispersed aqueous solution in which the recycled material is dispersed in water a separation step of subjecting the dispersed aqueous solution to centrifugal separation to separate the dispersed aqueous solution into a liquid component and a solid component; and a measuring step of measuring the concentration of protein in the liquid component using a protein measuring means.