Method for testing static and kinetic frictional coefficients of a sheet

Abstract

A horizontal plane frictional coefficient testing apparatus and methods are provided which include a substantially horizontal planar platen having two spaced, parallel movable rails. The rails are actuated by a motor adapted for reversibly raising and lowering the rails relative to the platen. A sled of predetermined weight is also provided having a central body and two pairs of outwardly extending axles, with each pair of axles being of equal length and formed with a wheel at the end thereof. The wheels of the sled are formed for engagement with the rails and engagement of the wheels with the rails locates the sled generally parallel to the rails. In operation, a sample of sheet material is fixed to the sled and the sled is placed on the rails, with the rails being in a raised position. Subsequently, the rails are lowered to gently place the sled onto the platen or a test medium fixed to the platen. A drive arm is included with the apparatus for pulling the sled relative to the platen at various rates of translation. A load sensor mounted on the drive arm measures in real time the force applied to the sled during the course of the test. The data collected by the load sensor is transmitted to a central processing unit which calculates the coefficients of friction. A timing mechanism may be provided to monitor the dwell time of the sled on the platen prior to initiation of the tests. Also, a semi-rigid coupling may be used to connect the sled to the drive arm.