Expanding the Bounds of Bioplastics

With the VINNEX® product range, WACKER offers versatile polymer additives for improving the material properties and ease of processing of bioplastics – making them more competitive with traditional plastics.

VINNEX® and polylactic acid bioplastic pellets: their high transparency makes them suitable for manufacturing film and blister packs.

The growing controversy about the catastrophic rise in plastic marine pollution has put producers of plastic food packaging and shopping bags on notice. Since July 1 of last year, about 240 German retail companies, including most of the major chains, have stopped giving away free plastic bags to customers. Retailers hope that this voluntary commitment, which follows Ireland’s example, will contribute towards reducing the rise in plastic waste.

Blister pack made from a VINNEX® and polylactic acid compound: the image here shows how the basic shape is achieved while ensuring that the wall thickness is evenly distributed.

In addition, the majority of food packaging and plastic bags are still manufactured from crude oil – this fossil fuel is currently cheaply available, though it is subject to major price fluctuations, and its reserves are finite.

“Bioplastics offer the market an alternative because they are manufactured from renewable raw materials, which, in contrast to crude oil, are continuously available and have a better environmental footprint,” explains Dr. Marcus Pfaadt, head of the Bioplastics market segment and business development manager at WACKER BIOSOLUTIONS. The global production of biopolymers is growing at a correspondingly fast rate of about 20% a year. Experts from the nova-Institute estimate that the global production capacity of bioplastics could rise to more than 6.7 million metric tons by 2018.

Bioplastics

Bioplastics, also called bio-based plastics or biopolymers, consist of a significant proportion or are exclusively made of renewable raw materials and/or be biodegradable.

Various technically sophisticated materials are now available that can replace the petrochemical reference products. This is particularly the case for bioplastics whose chemical structure is identical to that of conventional petro-based plastics: these include bio-PE (polyethylene) and bio-PET (polyethylene terephthalate; previously only partially available as a bio-based compound). These so-called drop-in solutions largely adopt the production processes of the petrochemical industry.

For other bioplastics such as PLA (polylactide = polylactic acid), PHA (polyhydroxyalkanoate) or TPS (thermoplastic starch), the ‘blueprints’ differ from those of petro-based plastics.

Potential biodegradability or compostability and having a bio-based content are not compulsory criteria for a bioplastic.

Source: German Agency for Renewable Resources

In the packaging field especially, bioplastics could make a significant contribution to greater sustainability. Many industries have recognized this fact. At least 80% of the bioplastics produced are already being used in packaging. Whether as shopping bags, blister packs, thermoformed trays for chocolates, trays for fruit and vegetables or film – bioplastics now cover a broad range of products. Their material properties and the ease of processing – long-standing critical issues for biopolymers – have also improved substantially in the past few years, which means that they can now replace many traditional plastics.