Polymorphism in a backpack

The backpack Aggregat is an example for the variable application possibilities of the bioplastic PHB. The modular design of the backpack combines polymorphic structures and realizes different functions in a mono material. The concept is based on a future scenario in which the bioplastic is already an integral part of industrial mass production.
The design incorporates circularity through the use of recyclates in manufacturing and through the easy reparability of the backpack. In addition, consumers are actively involved in the recycling process and introduced to the benefits of reuse. Aggregat also allows the product to be customized in terms of shape, colour and function, enabling the backpack to be adapted to consumers’ changing needs. The goal is to use the material as long as possible before returning it to the material stream through mechanical or chemical recycling.

video of Hannah’s presentation
Hannah Kannenberg
project:full circle
examined bioplastic:
Polyhydroxybutyric acid (PHB)
material expert support:
Dr. Gundela Peschel

full concept text

The Aggregat project follows the idea of a backpack made of polyhydroxybutyric acid, short PHB. The backpack demonstrates in an exemplary form how variable the materiality of the bioplastic can be in a variety of applications and what functions it can assume. This is because everything from the textile to the zipper and the paddings is made from only one material. Necessary properties of the backpack, such as stability, flexibility and wearing comfort, are realized by shaping the PHB in a specific form using polymorphic structures.
Even though PHB is still too expensive for mass production today, it will be possible to manufacture a wide range of everyday products from PHB in the future. For example, although the synthesis of the plastic by bacteria is quite expensive, it does neither require fossil resources, nor does the production compete with the food industry. A future-oriented way to produce PHB could be the synthesis of PHB in symbiosis of cyanobacteria and PHB-producing bacteria. Using carbon dioxide and sunlight, the cyanobacteria are able to generate polysaccharose, which provides a food source for the PHB-producing bacterium. The extracted PHB could be cast into films or further processed into various products using conventional plastic processing machines.

In the future, products made from pure PHB will be labelled with a new recycling symbol so that consumers can easily identify the bioplastic and return their PHB waste to a local Aggregat-Store for a small deposit.

The Aggregat-Store uses the collected waste PHB to make new products. Some of the material is cleaned, shredded, sorted by colour and extruded into 3D printing filament. Film-based products such as rain capes, tarpaulins, etc. are scanned for utility using an innovative technology and then punched into plug-in modules.

The aggregate backpack is completely modular. All components are connected and disconnected by plugging, clipping or screwing mechanisms, based on a flexible textile made from a large number of small basic modules. Without sewing or gluing, three-dimensional shapes can also be plugged in.

Additional functions such as hooks and clips, zippers or pockets on the inside or outside are simply added with the help of special modules.

In addition, based on the original design, the shape, size and colour of the backpack can be customized to match the individual needs of the user. By using recycled material, the aesthetics of the Aggregat is significantly determined by this material.

The customer can assemble the backpack according to his or her own wishes online or directly at the store. The Aggregat-Store also offers a DIY corner, where customers can use their own materials to create their own personalized pieces.

And if a backpack ever breaks, the store offers a free repair service. Broken modules are simply exchanged for new, suitable ones. Thanks to this easy reparability, the product is kept in a long-life cycle.

If a module has become unusable, it is melted down and processed into filament or new films and mechanically recycled.