Press release

Fraunhofer WKI presents vegetable crates made from natural-fiber-reinforced plastic at the K 2019 trade fair

Braunschweig / 1.10.2019

At K 2019, researchers from the Fraunhofer Institute for Wood Research, Wilhelm-Klauditz-Institut WKI, will be presenting vegetable crates comprised of up to 25 percent wood fibers. Transport and storage containers made from polypropylene are used millions of times every day in industry and in the wholesale and retail trades. The researchers at the Fraunhofer WKI have worked out how to make the containers more sustainable, lighter and sturdier – whilst keeping production costs at the same level. In the future, the researchers intend to transfer their expertise in materials research and injection-molding technology to other products.

© Hasan Mezdegi
Vegetable crates with wood-fiber content are more sustainable, lighter and sturdier.

Conventional vegetable crates are made from polypropylene. As polypropylene is petroleum-based, it would be expedient to replace the finite raw material content with the highest-possible proportion of renewable raw materials. Both wood and cellulose fibers fulfill this criterion, are regionally readily available and are relatively inexpensive. The utilization of wood fibers additionally makes the crate lighter. “If we consider the entire life cycle of the vegetable crate, the majority of the emissions are not created during the production of the material or through disposal, but during the use phase, due to repeated transport. The transportation of lighter vegetable crates would therefore be an advantage, as less CO2 would be produced,” explains Christoph Habermann from the Fraunhofer WKI.

During the development of the material, Habermann and his team not only took into account environmental aspects but also improved a number of application properties, such as stacking capability and resilience. “We are experts in materials research and innovative injection-molding processes, both of which are hugely influential factors. With the aid of computer simulations, for example for strength simulation, we are able to optimize the production time and the product quality,” says project member Carsten Aßhoff, and adds: “The vegetable crates are a good example: Through the wood fibers, the strength and rigidity of the crates is increased. As a result, the wall thicknesses could be reduced and the internal volume increased. Users could benefit from lower transport costs.“

The researchers’ analysis does not end with the production of new prototypes; they examine the entire life cycle of the products. “We can only achieve real sustainability within the packaging industry if we also take further use and recycling into account when addressing the material composition. Wood fibers are better suited for this than, for example, glass fibers, which are, to some extent, also combined with polypropylene. Vegetable crates made from wood-fiber-reinforced plastic can be melted down to make new transport containers,” explains Habermann.

The advantages of the material properties are not limited to vegetable crates; many other versatile possible applications exist, explains Aßhoff: “Our tests have been very successful and the acquired knowledge can, theoretically, be applied to all types of reusable containers and transport crates as well as all kinds of injection-molded parts. Furthermore, it would also be conceivable to use the materials for disposable products such as shampoo bottles. In the future, customers could then buy their organic shampoo in organic packaging.”

From 16th to 23rd October 2019, the Fraunhofer WKI will be presenting its vegetable crates on the Fraunhofer-Gesellschaft joint stand (in Hall 7, Stand SC07) at the K 2019 trade fair in Düsseldorf.



Sustainability through the utilization of renewable raw materials has formed the focus at the Fraunhofer WKI for more than 70 years. The institute, with locations in Braunschweig, Hanover and Wolfsburg, specializes in process engineering, natural-fiber composites, wood and emission protection, quality assurance of wood products, material and product testing, recycling procedures and the utilization of organic building materials and wood in construction. Virtually all the procedures and materials resulting from the research activities are applied industrially.