Coefficient of Friction Testing 

ASTM D 1894: Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting 

ISO 8295:Plastics - Film and Sheeting - Determination of the coefficients of friction

As stated in ASTM D 1894: "1.1 This test method covers determination of the coefficients of starting and sliding friction of plastic film and sheeting when sliding over itself or other substances at specified test conditions. The procedure permits the use of a stationary sled with a moving plane, or a moving sled with a stationary plane. Both procedures yield the same coefficients of friction values for a given sample." In short, COF is used to determine and measure the friction of a materials surface. This can be tested by running the two surfaces in plane contact under uniform contact pressure. The forces recorded during the uniform sliding of the film surfaces are averaged.

ASTM D 1894 - Fig. 1 Five Method of Assembly of Apparatus for Determination of Coefficients of Friction of Plastic Film

ST-330 Friction Tester

The ST-330 is Salts dedicated COF testing apparatus. The friction tester comes equipped with a force and displacement indicator which can be connected to PC to our testing software for better mangement of controls, reports, graphs etc.

ST-330 - Friction Tester

ST-1001 COF Stage and Sled

The COF test can be done on a UTM with the COF stage and sled accessory. This allows for more versatility as many films and plastic sheets require tensile testing, shear testing, tear testing etc. 

COF test accessories on ST-1001

On our Salt UTM software inputs and test parameters such as sample size, sled weight, test speed, pull distance etc. can all be easily adjusted to the testing requirements. Calculations such as averaging and COF values are all done post test and readily available in report format for printing or exporting. 

COF Testing

Test report - Averaging start (displacement) and end highlighted in gray