Development of laboratory wet creping method to evaluate and control pulp quality for tissue

The required properties of tissue paper including softness and liquid absorption are predominantly manipulated by the creping process, which cannot be simply produced in the laboratory. This causes problems in controlling the stock quality prepared using the various types of industrial pulps and consequently affects the creping operation and tissue quality. Our objectives were to develop a laboratory creping method and to apply it for the evaluation and control of the quality of pulp raw materials used in industrial tissue production. The experiment consisted of the development of a laboratory wet creping method and the study of the creping devices and the creping conditions, including basis weight of the base paper, sheet dryness, and degrees of pulp refining. The results showed that the method could produce crepes on laboratory sheets and the structures of the creped sheets could be engineered to improve their softness and liquid absorption. The tested pulps were found to produce significantly different responses to the laboratory wet creping, depending on their morphology and the mechanical treatments. The examination of industrial pulps found that eucalypt, bagasse, bamboo, and deinking pulps needed to be manipulated using different refining levels and required optimization among their softness, liquid absorption, and strength properties.