Measurement of Friction Coefficients of Films
【Standard Number: ASTM D 1894-95 (JIS K 7312-1996)】

Plastic films are used for coating and wrapping various materials. When used for these purposes, measuring the friction between films or a film and a different type of material is often required. For example, friction coefficients of films used on foods and protective films for smartphones are often measured. This article introduces an example where static and dynamic friction coefficients of a polyethylene film were measured in accordance with the ASTM standard.

Measurement and Jigs

The standard specifies the procedure to determine the coefficients of starting and sliding friction of plastic films and sheeting. The test was performed on polyethylene films using the AGS-X Table-Top Type Precision Universal Tester and a friction modulus test device. Two pieces of a sample, one moving and one fixed, were prepared. The moving sample (63.5 mm-side square) was attached to a metal sled with double-stick tape and the fixed sample (at least 130 mm wide and 250 mm long rectangle) was attached to a fixing base with double-stick tape.

Measurement Results

Fig. 1 Test Status

Fig. 2 Test Results

 Table 1 Test Conditions
Item Set Value
Test Speed  150mm/min
Movement Distance  130mm
Load Cell Capacity  5N

 Table 2 Test Results
Static Friction Coefficient Dynamic Friction Coefficient
0.21 0.17

 Friction Coefficient Measuring System
 Tester  AGS-X
 Load cell  5N
 Test jig  Friction modulus test device
  • A high-precision load cell is adopted. (The high-precision type is class 0.5; the standard-precision type is class 1.)
    Accuracy is guaranteed over a wide range, from 1/500 to 1/1 of the load cell capacity. This supports highly reliable test evaluations.
  • Crosshead speed range
    Tests can be performed over a wide range from 0.001 mm/min to 1,000 mm/min.
  • High-speed sampling
    High-speed sampling, as fast as 1 msec.
  • TRAPEZIUMX LITE X operational software
    This is simple, highly effective software.
  • Jog controller (optional)
    This allows hand-held control of the crosshead position. Fine position adjustment is possible using the jog dial.
  • Optional Test Devices
    A variety of tests can be conducted by switching between an abundance of jigs in the lineup.