Thomas Engler

A novel processing solution for the production of spatial three-dimensional stitch-bonded fabrics

Spatial three-dimensional (3D) stitch-bonded preforms offer a huge potential and an optimal utilization of the fiber mechanical properties for their usage in various technical applications. These preforms form an efficient alternative to the existing two-dimensional textile preforms due to their load-bearing fiber orientation offered by their geometrical configuration. The fundament of this research activity, based on the stitch-bonded technology, is the development of a new processing solution for producing 3D spatial open stitch-bonded textile preforms with minimal processing stages. Based on a newly developed concept with variable warp yarn delivery and differential doffing, this technology is principally enhanced so that various helical, circular and curved grid structures, along with 3D spatial structures, could be produced on a single machine with minimal setup, which hitherto has not been realized with any other existing processing technique. These novel form-based textile preforms are found to be suitable for application as reinforced components in complex spatial composites with a mineral or a plastic-based matrix, wooden composites and elastomers.

Weiterverarbeitungsaspekte und Anwendungsbeispiele

Die weltweite Energie- und Klimasituation erfordert, dass zukunftig alle Moglichkeiten zur Senkung des Energieverbrauchs, nicht nur in der Verkehrstechnik und im Bauwesen, sondern auch in allen Wirtschaftszweigen ausgeschopft werden. Der Leichtbau mit textilverstarkten Verbundwerkstoffen bietet bei der Entwicklung energieeffizienter und funktionsintegrierender Strukturbauteile faszinierende Moglichkeiten gegenuber konventionellen metallischen Bauweisen. Aus der Kombination von zwei oder mehreren unterschiedlichenWerkstoffen resultieren neuartige Verbundwerkstoffe, deren Leistungsfahigkeit die Summe der Eigenschaften der Einzelkomponenten ubersteigt.

Aspects of Creep Behavior of Textile Reinforcements for Composite Materials~!2009-03-04~!2009-10-15~!2009-12-11~!

Numerous technical applications utilize fiber reinforced composites made with high performance glass and/or carbon fibers. These fibers are especially desirable due to their mechanical and chemical properties resulting in high tensile strength. A relatively new application field is textile reinforced concrete (TRC), which is composed of a textile structure made up of multifilament yarns (rovings) and a cement matrix. To guarantee that the fibers retain their strength over long periods of time in an alkaline milieu, alkaline resistant materials such as alkali-resistant glass fibers (AR-glass) are used. Further requirements placed on textile reinforcements include excellent mechanical properties, such as high strength and stiffness, which remain unchanged or are nominally altered under long-term stresses. These properties will be discussed in this paper within the framework of an experiment conducted, which observed the behavior of AR-glass rovings under continuous long-term stress relative to time. The paper analyzes and interprets the results obtained on the yarns’ mechanical properties. The objective was to develop a mechanical model of the material behavior of the textile structures to aid in the prognosis of long-term behavior of textile reinforced composite materials (i.e. textile reinforced concrete).

Processing Aspects and Application Examples

The global energy and climate situation requires future activities to reduce energy consumption as much as possible, not only in transport technology and the construction sector, but also in all other industries. Lightweight construction with textile-reinforced composite materials offers fascinating possibilities in developing energy-efficient and function-integrated structural components, especially when compared to their conventional metallic counterparts. The combination of two or more different types of material results in novel composites, whose performance exceeds the sum of properties of the individual components.