Rheological characterization of tack and viscoelasticity of compositions of crepe coating used in the Yankee dryer

摘要

The vast majority of tissue production uses creping to achieve the required set of properties on the base sheet.The Yankee coating helps to develop the desired crepe that in turn determines properties such as bulk and softness.The adhesion of the sheet to the Yankee surface is a very important characteristic to consider in achieving the desired crepe.The coating mix usually consists of the adhesive,modifier,and release.A good combination of these components is essential to achieving the desired properties of the tissue or towel,which often are determined by trials on the machine that can be time consuming and lead to costly rejects.In this paper,five compositions of an industrial Yankee coating adhesive,modifier,and release were examined Theologically.The weight ratio of the adhesive was kept constant at 30% in all five compositions and the modifier and release ratios were varied.The normal force and work done by the different compositions have been shown at various temperatures simulating that of the Yankee surface,and the oscillatory test was carried out to explain the linear and nonlinear viscoelastic characteristic of the optimal coating composition.Application: Towel and tissue producing mills can predict the behavior of coating compositions before performance trials are carried out on the Yankee dryers.Combinations of coatings can be tested for their rheological properties to determine which composition will give the best creping and quality performance without the need for large-scale machine trials.