Anti-block functional additives are another important tool in the material arsenal for plastics processors. This highly useful additive reduces the friction on the product surface and imparts lubricity for ease of use. In all types of plastic films for flexible packaging and other applications, anti-blocking performance it vital for further handling and converting of the material. Plastic layers tend to stick together and the addition of an anti-blocking agent creates space between two plastic layers (surface roughness) thus preventing a phenomenon called blocking.
Anti-blocking is most commonly found in the production of polyethylene and polypropylene films (either blown or cast). During film rolling, air bubbles can be trapped between successive layers which can cause small localized flaws that grow as the layers pile up. The film rolls that are manufactured are no longer cylindrical, and the film isn't perfectly flat when it is unrolled.
In order to resolve these problems, the film must be given roughness by incorporating specific fillers, whether organic or mineral in nature. The greater the concentration of anti-block results in a rougher film surface. However, it is important that the particles are well dispersed as agglomerates reduce anti-blocking performance. Conversely, the coarser the particles the further the two film layers are kept apart.
Anti-block masterbatches can be produced in a wide range of polymers including polyethylene, polypropylene, ionomers, polyamides, thermoplastic polyurethanes, and others. Combinations with antistatic and slip products offer cost-effective products for use in the film industry. Plastics Color provides a masterbatch at a specific letdown ratio or we can compound directly into the material.
Plastics Color delivers on more than 50 years of experience and works with a broad base of polymers and formulations to meet the needs of a wide range of applications. Let us know how we can satisfy your product needs. E-mail us at Info@PlasticsColor.com.