Control Damages Caused Due to Friction on Packages During Storage

Control Damages Caused Due to Friction on Packages During Storage

Plastic films are used for coating and wrapping various materials. When used for these purposes, measuring the friction between films and a different type of material is required. For example, friction coefficients of films used on foods and protective films for smartphones are often measured. Plastic film is used in the packaging industry and includes many types of food packaging such as produce bags, carton liners, meat seal wrap and non-food packaging such as envelope liners, potting soil sacks. Plastic films are used by other industries to produce items like trash bags, construction liners, and I.V. bags. To ensure that they perform as expected for the end-user, the frictional properties of these films must be characterized and controlled (Polyfilms and Laminates Testing Instruments).

A packaging film’s coefficient of friction (COF) provides a relative indication of frictional characteristics.  Controlling COF gives processors the ability to optimize performance and avoid problems informing, transporting, and storing packages. COF can be affected by several factors including anti-block additives, corona treatment, anti-statics, inks, varnishes, adhesives.  Because laboratory testing cannot simulate every element of any packaging process, COF should not be considered an indication of system-specific performance.  It is, instead, a means of reproducing frictional properties shown to be successful under a given set of conditions. 

Coefficient of friction testing is used to test with the frictional bonding in which two surfaces in contact can slide past one another. Mainly two different values associated with the coefficient of friction one is static and another is kinetic. Static friction applies to the force necessary to initialize motion between the two surfaces and kinetic friction is the resistance to sliding once the surfaces are in relative motion.

The sample used for testing is kept clean as it impacts the gathering of reliable data. The appropriate measures are taken, before testing and taken to during testing ensure freedom from dirt, grease and other contaminants that could adversely affect test results.

A Coefficient of Friction Tester measures a sheet-like substrate such as paper, corrugated, plastic film or paperboard which determines the angle of inclination at which one substrate affixed to a sledge will begin to slide or slip against the surface of another substrate of similar material.

During a test, an inclined plane is increased at a constant speed by an electric motor until the test block begins to slide.  The initial movement of the sledge is the slide angle or coefficient of static friction of materials.  When the test block just begins to slide a photo-optical sensor automatically stops the inclined plane and the operator can read the slide angle result.