Abstract:

The rheological properties of the one-step producing toothpaste and the two-step producing toothpaste were researched by Anton Paar MCR 302 Rheometer in this paper. Results show that the two toothpastes are the pseudoplastic fluids with shear thinning behavior and the thixotropy. The two-step producing toothpaste has higher viscosity, greater yield strength and rigid structure. The one-step producing toothpaste is more elastic, and its structure recovers quickly after high-speed shearing. The temperature has more influence on the one-step producing toothpaste, and its viscosity can increase after high temperature treatment. The two-step paste production process includes the thickeners hydration and swelling procedure. In the one-step paste production process, the thickeners hydration and swelling procedure is carried out simultaneously with the abrasive adsorbing liquid material procedure, the foaming agent dissolution and emulsification procedures. Comparing with the one-step paste production process, the temperature and liquid concentration are higher during the thickener’s hydration and swelling procedure in the two-step paste production process. So, by the two-step paste production process, the molecular chain of the thickeners combines more water, unfolds more and twines more. The toothpaste has a greater cohesive force and the structure is more rigid.

Key words: toothpaste, one-step paste production process, two-step paste production process, rheological properties