Abstract: In order to get the frictional characteristices of mailing matter on the postal machine, the special two-dimensional force sensor andthe pin-disk attrition testing machine with the function of variable relativesliding velocity and normal pressure are designed.The coefficient of friction between typical packing materials of matter and mail handing equipment in different sliding speeds and acting loads is measured and analyzed.The testing results indicate that the coefficient of friction between mailing matter and the postal machine shows a slowly growing tendency within the scope of pracical velocity ofmailing matter when the sliding velocity is increased.

Key words: mail handing equipment, specific property of materialfriction, testing technique