Basic principles used in the development of a new cut-test machine for standardization

摘要

A new cut-test apparatus for standardization has been developed. The apparatus is based on a previously developed cut-test method that consists of sliding a blade on a material and determining the distance traveled by the blade to cut through the material when a constant force is applied. To build a machine for standardization, several requirements were considered. One of the most important requirements was that the force applied at the blade/material point of contact must be constant throughout the test. Other requirements were that the test apparatus be easy to use by an untrained person, that the applied force should be known, and that the results should be reproducible. The force is applied at the material/blade point of contact from bottom upwards through a ram-type arm. To satisfy the requirements, a mechanism based on a double Watt system was developed that allows a perfect vertical displacement of the sample and a constant applied force throughout the test with a maximum error of 2x10~(-2)N.