Lubrication Study Of Representative Fluid Food Under Mimicked Oral Surfaces

In this paper,the friction behavior and lubrication mechanism of representative Newtonian fluid food such as water and glycerin under simulated oral surfaces were investigated.And the influencing factors were explored too.The purpose of this study is to provide new insights into the friction and lubrication process of fluid food in oral cavity.At the same time,it provides reference for the development and production of different kinds of healthy and delicious food,so as to adapt to different age groups and oral physiological environment.People’s individual oral processing status and oral physiological characteristics are different,such as swallowing speed,tongue and palate extrusion force,surface properties and elastic modulus.From the above perspectives,the influence mechanism of different oral physiological conditions on the lubrication performance of fluid food in oral processing was explored.The main research contents of this paper are as follows:Based on the different oral physiological environment caused by individual differences,food friction and lubrication test conditions simulating oral environment were established.Different mass fractions of water-glycerol solutions were prepared to simulate Newtonian fluid foods with various viscosity.The rheological properties of the fluid samples were tested.The physical properties of friction pair materials were characterized.The micro-convex body and texture on the surface of friction pair were observed,the contact angle of each lubrication solution on the surface was measured,and the mechanical properties of rubber friction pair were measured.The lubrication properties of liquid food with different viscosity were studied by glycerin solutions with different mass fractions under different speeds and loads.It is to explore the lubrication law of fluid food in different oral processing states.In addition,the effects of different friction pair materials on the lubrication properties of glycerol solutions were investigated to mimic the influences of various oral physiological environment on the lubrication properties of fluid food.It can provide suggestions for the food design and development of different age groups and people with swallowing disorders.The friction mechanism of rubber material was studied from the contact of elastomer material.An elastohydrodynamic lubrication(EHL)model for tongue contact with palate was established based on silicone rubber materials.And the EHL problem of oral friction behavior under Newtonian fluid condition was investigated.A method to calculate the friction coefficient of EHL was presented.