This Coefficient of Friction Testing Device (C.O.F) has an Incline Plane. The instrument is useful to determine the coefficient of static friction. The applications include most packaging materials including plastic films, paper, etc. It does so by measuring the angle at which one test surface begins to slide against another. And tests how friction changes as the incline increases. It rises at a constant and previously set rate. The Coefficient of Friction Tester incline plane complies many international testing standards.
The coefficient of friction of packaging materials indicates how packages made from that material will perform in many critical applications. A high coefficient of one surface of paper or paperboard (containerboard) to itself means that containers having that surface will tend to resist sliding in unit loads. A low coefficient may indicate potential problems with the packages slipping from the load.
As the plane rises at a rate of 1.5° ±0.5°/s, the first sign of movement from the sled is detected by a micro switch. And stops the plane movement and records the relevant angle of the incline. Thus, many refer this test as slide angle. The coefficient of friction is numerically equivalent to the tangent of that angle.
Coefficient of Friction Testing Equipment - Incline Plane Parts
The IDM COF consists of the following parts:
- Sled: A rectangular metal block used to hold the test piece
- Bullseye Level: Indicates when machine is level, the inclined plane is level when bubble is inside red circle.
- DPM: Digital read-out of inclined angle in degrees.
- Resolution- 0.1 degrees, Accuracy- 0.5 degrees
- Microswitch: Senses when sled has moved, will then stop inclination
- Levelling Feet: Located underneath, used to level machine
Test Sample Preperation for COF Test
These test methods cover procedures for sampling and testing untreated paper to be used as an electrical insulator or as a constituent of a composite material used for electrical insulating purposes. Untreated papers are thin, fibrous sheets normally laid down from a water suspension of pulped fibers (usually cellulosic) with or without various amounts of nonfibrous ingredients, and which are calendared, if required, to obtain desired thickness and density. Nevertheless, these test methods are applicable, generally although not invariably, to papers formed by other means, to papers modified (during or after formation) by additions, and to papers given subsequent mechanical treatments such as creping.
Coefficient of Static Friction Test
The coefficient of friction is the ratio of the frictional force resisting movement of the surface being tested to the force applied normal to that surface (the weight of the material above that surface). For the inclined plane, the coefficient is numerically equal to the tangent of the angle of incline. This method determines the coefficient of static friction of most packaging materials by measuring the angle at which one test surface begins to slide against another inclined surface as the incline is increased at a constant and prescribed rate. The test is frequently referred to as slide angle. The coefficient of friction is numerically equivalent to the tangent of that angle.