Most polymers have a low surface energy, which results in difficulties when further processing (e.g., coating, printing, or gluing) and requires the use of surface treatment to increase the surface energy. Though many different surface treatments exist, the most well-known methods include flame treatment, corona treatment, and the use of wet primers. Flame and corona treatment increase the surface energy of materials by oxidizing them, while wet primers introduce chemical functions on the surface to increase the surface energy.
Figure 1. Illustration of the competition between functionalization and degradation of the material during corona treatment.