| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for making white cardboard which uses both a paper-strengthening agent and aluminum sulfate and is excellent in interlaminar strength, even when the white cardboard is made at high temperature. SOLUTION: In the method for producing white cardboard having three or more layers which uses 100% waste pulp as raw material pulp, and aluminum sulfate and an amphoteric polyacrylamide, as a paper-strengthening agent, in which the amount of cation is 1.5 times or more of the amount of anion are added to the same position in a machine chest or at a front place of the machine chest, at a temperature of 40°C or more, and at a pulp concentration of 2.5% or more. COPYRIGHT: (C)2011,JPO&INPIT
|
