Electrostatic Issues in BOPP Film Production and Solutions

Electrostatic charges in film production arise primarily from the following causes:

Electrostatic Generation During Film Production
Static electricity is generated during film production due to friction between polymer particles, friction between the melt and the die, and friction between the formed film and guide rollers during winding. To address this, antistatic agents are added during the production process, which are highly effective. Antistatic agents are surface-active compounds containing polar hydrophilic groups and non-polar lipophilic groups. The lipophilic groups interact compatibly with the plastic, while the hydrophilic groups ionize or adsorb moisture from the air, forming a thin conductive layer on the film surface. This layer dissipates charges, thereby eliminating static electricity. While this method is widely used, excessive amounts of antistatic agents may complicate downstream processes (e.g., lamination or heat sealing).

Electrostatic Generation During Printing, Lamination, Slitting, and Bag-Making
Static charges are generated during these processes due to friction between the film and guide rollers or between high-speed moving film and dry air. This type of static has the most significant impact on production and downstream processes if not properly managed. A highly effective solution is the use of superconductive static eliminator brushes (contact-based elimination), which ground the static charges through low-resistance brushes in contact with the film. Alternatively, ionizers (non-contact elimination) can blow ionized air onto the film. However, ionizers may inadvertently allow residual charges to remain on the film during winding. Comparatively, static eliminator brushes are more cost-effective, safer, and reliable, provided they are installed correctly with proper grounding (e.g., connecting the ground wire to the equipment’s electrical cabinet grounding terminal).

Electrostatic Generation on Finished Films in Automated Packaging Machines
Residual static on finished films or friction with machine rollers can cause packaging difficulties or affect electrostatic-sensitive contents. The superconductive static eliminator brush method remains the most effective solution here.

Common Misconception: Many manufacturers assume that metal guide rollers inherently ground static charges generated by friction. However, most rollers undergo surface treatments (e.g., anodization), forming an aluminum oxide layer (Al₂O₃), which is non-conductive. Additionally, equipment grounding is often inadequate. Thus, dedicated grounding for static eliminators is critical.

Nanjing Sumino Precision Machinery Co., Ltd., known as Sumino Precision, is located in Jiangning District, Nanjing, covering an area of 8,000 square meters. As a Sino-Japanese joint venture, we boast advanced technology and comprehensive services. Sumino Precision is a professional manufacturer integrating equipment R&D, manufacturing, and sales. For thirteen years, we have specialized in the fields of cast film machines, laminating machines, coating machines, and stretching machines, including biaxial stretching machines, covering production lines for plastic films, sheets, and boards.

Sumino Precision, while continuously expanding its domestic business, adheres to an overseas development strategy. Our products have been exported to Southeast Asia, the Middle East, North America, South America,and Western Europe. We have delivered over 300 projects in total, with more than 100 projects successfully completed since our independent establishment. We have over 200 cooperative suppliers and have obtained multiple technical patents and certifications.