Technical plant stem

Milwich et al. (2006) combined ideas of cellulose fiber orientation in wood with the structure of the stem of giant reeds to create a hybrid model realized using advanced braid protrusion machinery at the Institute of Textile Technology and Process Engineering (ITV) Germany. The outcome called Technical Plant Stem is a commercially scalable architectural textile composite that demonstrates excellent strength and impact resistance with the minimal material use (Speck and Speck, 2006). 

Fibre-reinforced composite materials are relatively new and are of interest for primary constructions. These materials are lightweight and may easily be processed into complex forms. In specifically designed primary constructions, the natural forms of organic membranes may have a counterpart in bionic development such as the technical plant stem , which is formed on a model of giant reeds and horsetail (Milwich et al. 2006). 

Learning from nature lightweight constructions using the technical plant stem ... 

Key words technical plant stem, technical textiles, biomimetic, natural role model. 

Whereas other bionic solutions in the field of composites are mostly founded on a single natural function, the seven different natural functionalities mentioned above were combined and translated into a concept of a technical fiber composite material with superior mechanical properties. A first computer modeling of the structure is shown in Rg. 9.12. The advantages of the new composite material were self-evident in such a way that specialists from prominent composite companies - seeing the FEM calculations and later the first prototypes of the technical plant stem - encouraged the inventors to patent this so-called technical plant stem . 

One of the desired features of the technical plant stem is improved torsional stability and oscillation damping. As mentioned, the diagonal fiber bundles can be incorporated into the technical plant stem via a braiding machine, which was installed in-line with the pultrusion process (Figs 9.13 and 9.14). 

By combining this cost-efficient production method with the several advantages of the technical plant stem, this unique material will rapidly spread into manifold applications in the composite world. 

There are numerous applications for the technical plant stem . In most cases, where tubular rods are used - and there is an abundance of applications for tubular rods - the structure of the technical plant stem will enhance the performance of the original rod in terms of mechanical properties like pressure resistance or bending stiffness. Either the rods will be stiffer and stronger or the rods will be lighter than other composite materials.Therefore aerospace, automotive, building, and sporting goods can profit from this new development. 

Technical plant stem with polyurethane foam matrix. 

Application of technical plant stem lightweight load-carrying roof substructure (courtesy Exel-Oy). 

In other cases, the multi-channel system will offer new functionalities like integrated gas, fluid or power transport. A very interesting application in the building industry would be the use of the side channels for incorporating pultruded carbon composite rods. The carbon rods could be incorporated and fixed during the pultrusion process of the technical plant stem under a certain pre-tension load. The use of the technical plant stems as... 

Application of technical plant stem stiff and lightweight substructure for a telescope. 

Milwich, M., H. Planck, T. Speck, and O. Speck. 2007. The technical plant stem a biomimetically inspired narrow fabric. Melliand - Narrow Fabric and Braiding Industry 44 34-38. 

The technical plant stem , as developed by the Plant Biomechanics Group of the University of Freiburg and the Institute for Textile and Process Technology (ITV) in Benkendorf, is described in a separate chapter in this book. It is the result of biomimetic research based upon a great number of structural principles from different plant species. After a comprehensive... 

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