Polymer–polymer friction as a function of test speed

✍ Scribed by M. C. Gascó; F. Rodriguez; T. Long

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 167 KB
• Volume: 67
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980314)67:11<1831::aid-app1>3.0.co;2-m

✦ Synopsis

Tests of sliding friction between identical polymer films have been carried out at sliding speeds of 0.0001 to over 10 m/s. In order to make measurements over such a wide range of speeds, three devices are employed. In each apparatus, a moving member with two identical polymer surfaces slides between two stationary blocks covered with the same polymer. The slow-moving crossarm of a standard Instron tester provides speeds of 0.0085 to 0.21 cm/s. A horizontal sled apparatus provides speeds of 1 to 10 cm/s. Finally, a modified impact test machine uses a pendulum that moves at about 3 m/s. Results with four polymer films illustrate a variety of behavior. The coefficient of friction, m, for cellulose acetate decreases with increasing speed. Films of low-density polyethylene and polytetrafluoroethylene show increases in m with speed. A film of ultrahigh molecular weight polyethylene shows only a slight decrease in m with speed.