Adjacent layers in PE and PP films often stick together or are “blocked” due to Van der Waals forces in the polymers’ amorphous areas. This makes blow films use difficult.
The best way to overcome this issue is using anti-block masterbatches. This masterbatch creates a thin layer on the film, eliminating the Vander Waals attraction forces between the films and preventing layers from sticking together.
The main disadvantage of adding anti-block agents based on mineral substances, is reducing the level of film transparency. This problem could be largely solved by the correct choice of raw materials, suitable formulations and correct processing.
Film anti-block quality is tested using the ASTM D-3354 Parallel Plain Method.