Food packaging and print industries often face the obstacle of adhering to low energy substrates such as polypropylene. Measuring the surface’s cleanliness prior to bonding or printing is the key to successful adhesion. The common method for measuring surface cleanliness, or surface energy on these materials is dyne inks. However, dyne is highly subjective and requires a skilled technician, and because of its destructive nature, dyne can only be used on a sample rather than an actual material on the assembly line. These downfalls often restrict the use of dyne inks.

This paper examines the relationship between surface energy and adhesion and how water contact angle provides an accurate and quantitative method for predicting adhesion.  The results of this paper reveal that the Surface Analyst, a handheld water contact angle measurement instrument is an accurate and effective indicator of surface energy.

Using samples of treated and untreated bi-axially oriented polypropylene (BOPP) the Surface Analyst measured the various surfaces and revealed the differences between treated and untreated samples. Thus, the Surface Analyst is used in many applications to develop optimal adhesion specifications and surface treatment process, verify surfaces are ready for bonding after each step in the assembly process, and monitoring surface treatments processes such as plasma, corona, and flame.

To read the full article, examine intriguing figures, and learn about the Surface Analyst’s application on polypropylene, go to “Various Measurement Techniques on Packaging Polypropylene” on our technical resources page.