Problem description and significance: 

Tissue paper is a low-density paper product commonly used for hygiene purposes. The manufacturing of tissue paper usually involves a key operation called creping. In this process, the wet web is continuously pressed onto the hot surface of a rotating cylinder sprayed with adhesive chemicals, dried in place, and then scraped off by a doctor blade. Creping is understood as a periodic delamination and bucking process which generates a series of micro-folds in the web. Despite its importance in tissue making, the published scientific literature on creping is limited. For competitive advantage each manufacturer retains the proprietary knowledge developed in-house through painstaking and costly trials. Thus it is meaningful to develop a theoretical model to simulate the process and provide guidance to the industry.

A high speed video of the process, imaged by our lab, is shown below.

Recently we have developed a particle dynamics model to simulate the creping process. It models the paper as a series of discrete particles connected by spring-damper systems and the delamination is modeled by a cohesive zone model. Our model successfully captures the effects of the key parameters involved and predicts the stiffness and stretch of the tissue paper. Other than modeling, we have also experimentally captured the folding mechanism during creping at industrial speed by high speed imaging study.

Selected Publications

1. Das, R., Pan, K., Green, S., Phani, A.S.,2020, “Creped Tissue Paper: A Microarchitected Fibrous Network, ” Advanced Engineering Materials, 23, 20007777.
   
2.  Pan, K., Phani, A.S., Green, S., 2020, “Periodic folding of a falling viscoelastic sheet,” 101(1), 195408.
3. Pahn, K., Das, R., Phani, A.S., Green, S., 2019, “An elastoplastic model for tissue manufacturing,” International Journal of Solids and Structures, 165, 23-33.
4. Pan, K., Phani, A. S., and Green, S., 2018, “Particle Dynamics Modeling of the Creping Process in Tissue Making,” ASME J. Manuf. Sci. Eng., 140(7), p.071003.
5. Pan, K., Phani, A. S., and Green, S., 2017, “Mechanics of Creping Process in Tissue Making: Modeling and Experiments”, Tappi Papercon Conf., Minneapolis, USA.
6. Pan, K., Phani, A. S., and Green, S., 2016, “Particle Dynamics Modeling of Buckle Delamination of Thin Film Materials”, Proceedings of the 24th International Congress of Theoretical and Applied Mechanics, pp. 2092-2093.
7. Pan, K., Phani, A. S., and Green, S., 2016 “Mechanics of creping in tissue make: modeling and experiments”, PACWEST, Jasper, Canada.

Funding and Collaborators: 

This project is funded by the Natural Sciences and Engineering Research Council through the Collaborative Research and Development grant (501467-16) in partnership with FPInnovations (Canada), Kruger Products (Canada), and Solenis (USA). We work with these industrial partners and with Prof. Sheldon Green at UBC.