Production of three-dimensional moldings from water-repellent popcorn
The present invention relates to moldings made from popcorn, which has been hydrophobicized with a polymer. This allows for production of very light, flexible and water-repellent moldings. In particular, the moldings consist of renewable raw materials. Applications are e.g. for packaging and consumer goods industry.
Today, molded parts (from polymers) like packaging materials are mainly made of polypropylene, polyethylene, polyvinyl chloride and polystyrene. Although they have positive properties such as low density, hydrophobic surfaces, good processability and low thermal conductivity, they also have numerous negative properties. For example, the material is often brittle, has very low chemical resistance and a very low melting temperature. In addition, these plastics are made from finite fossil raw materials, some of which are difficult to reuse. The increase of plastic waste on land and especially in the oceans is becoming an ever greater ecological problem of global significance. Due to these problems, alternative solutions are urgently needed.
Scientists at the Georg-August-University of Göttingen, Germany developed molded parts consisting of popcorn (expanded grains) and a small amount of polymer. Due to the polymer content, these moldings have improved and excellent properties such as improved flexibility and water-repellent (hydrophobic) properties. In particular, they can be produced predominantly from renewable raw materials. The granulated popcorn used for the production of the three-dimensional moldings is coated with a polymer before molding. Due to this coating, the popcorn can be stored very well as a pourable granulate before further processing.
Formpressen (Bild 1):
The two techniques, compression molding and automatic molding have been further developed to produce the inventive molded parts. Depending on the application, the surface of the molded parts can then be coated or laminated.
Compression molding (Fig. 1):
Use of automatic molding machines (Fig. 2):
Bild 1: Formpressen (Quelle: DE102018132738.2)
Various molded parts (prototypes) were successfully manufactured and tested.
An international patent application has been filed (applicant: Georg-August-Universität Göttingen Stiftung Öffentlichen Rechts).
Homepage AG Chemistry and process engineering of composite materials:
Dr. Stefan Uhle