Modeling the penetration of polymer into paper during extrusion coating
A simple model based on Darcy’s law has been proposed to predict the penetration of polyethylene into paper and paper.
During the extrusion coating of paper or paperboard, a molten film of polymer is pressed against a paper surface to generate waterproof packaging materials. Hot-melt glues are also applied to various porous materials and paperboard to generate packaging. In both cases, the penetration of the polymer into the pore space influences the product performance and the ability of the product to be recycled at the end of life. While there is much experimental work discussing various parameters in these operations, little theoretical work has been reported.
Now, a simple model based on Darcy’s law is proposed to predict the penetration of polyethylene (PE) into paper and paper that has been coated with cellulose nanofibers (CNF). Another model, based on the flow of a polymer into a pore that includes dynamic heat transfer has been developed, where the viscosity is a function of temperature.