Biopolymers – Easy to Process - Wacker Chemie AG


Biopolymers – Easy to Process

Biodegradable food packaging is gaining in popularity. The new VINNEX® binder system now enables enhanced processing of bioplastics and reduces the film’s noise levels.

Environmentally Conscious Consumers

According to a study by consulting firm Frost & Sullivan, bioplastics are particularly sought after by the food sector, where consumers are increasingly demanding biodegradable packaging and are willing to pay higher prices for it. Reports about huge plastic garbage vortexes the size of central Europe in the world’s oceans have alarmed environmentally aware consumers. However, the Frost & Sullivan study claims that the success of the bioplastics market also depends on the development of new technologies to enhance the quality and properties of the materials used. “Companies are working on innovations in various technology fields to improve the properties of existing biopolymers and their discoveries may greatly change the way plastics are used in packaging applications,” explained Sujatha Vijayan, a research analyst at the US-based consulting firm.

New Blends Enhance Properties

One of these companies is Wacker Chemie AG: to compensate for biopolymers’ remaining shortcomings, WACKER developers are relying on the principle of polymer blends, thus a mix of synthetic and biobased polymers. Adding the VINNEX® vinyl-acetate-based binder now enables the development of significantly higher-performance biopolymer blends that cover a more diverse application and processing spectrum.

Typically, the blends contain between five and 30 percent of the added binder. The additive considerably enhances the physical properties of the bioplastics, which are otherwise difficult to process. To an extent depending on the VINNEX® content and grade, the polymer blends have higher impact strengths, are more resistant to melting or are more flexible than the pure biopolymers.

The Product

VINNEX®

is a plasticizer-free binder based on vinyl-acetate homopolymers, copolymers and terpolymers. It now also enables easy processing of biopolymer blends. For example, these new blends can be processed into food packaging materials, brochures, parts for electronic appliances or self-degradable gardening and agricultural containers.

Same Equipment Used

The polymer-blend formulations can now be adjusted so that plastics processors can use the same equipment for the bioplastics as for conventional thermoplastics – from injection molding, extrusion, blown film extrusion, vacuum forming and thermoforming, to calendering. Furthermore, thanks to VINNEX®, it is now much easier to get the bioplastics to assume the desired shape.

The enhanced binder is compatible with all kinds of biopolyesters. As the system is modular, it is also possible to combine various VINNEX® grades – either powder or solid resin – with one or more bioplastics and fillers. Thus, various polymer blends can be obtained by combining VINNEX® with starch, polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylene succinate (PBS) or cellulose acetate (CA). As a result, the properties are customizable. In the case of PBS, since VINNEX® lessens its tendency to recrystallize and improves the melting resistance, the polymer blend can be thermoformed to yield stable, three-dimensional structures.