Hartmut Rödel

Links between design, pattern development and fabric behaviours for clothes and technical textiles

Shows the necessity of developing powerful 3D CAD‐systems for the textile and clothing industry. The connection between 2D and 3D CAD‐systems enables the user to prepare a collection more quickly and accurately. Applications could be the drape behaviour of the fabric, the deformational behaviour of fabrics when covering defined surfaces and also technical textiles.

Simulation of drape behaviour of fabrics

In this paper a model is presented for the calculation by approximation of a drape test standardized in the textile industry. As woven fabric is of low thickness compared with the other dimensions, the fabric can be considered to be a two‐dimensional continuum. For the simulation model, the shell theory is taken as a basis. Simulating the drape behaviour presents a geometrically non‐linear field problem with considerable displacements.

Konfektionstechnik für Faserverbundwerkstoffe

Mit konfektionstechnischen Prozessen werden die Halbzeuge aus den textilen Flachenbildungsprozessen zugeschnitten, in die Form der endkonturnahen trockenen Preform umgeformt, montiert und fur den Verbundwerkstoffherstellungsprozess vorbereitet. Dies umfasst Schnittkonstruktion der Preform-Einzelteile, Nesting und Lagenlegen als Zuschnittvorbereitung, Zuschnitt und textile Montage der Preform vorwiegend mittels Nahen, Schweisen und Kleben. Zum Gewahrleisten der mechanischen Funktionalitat des Compositebauteils sind die Halbzeuge auszuw ahlen und belastungsrichtungsgerecht in den Aufbau der Preform zu integrieren. Dies muss ohne Faltenbildung und nur mit definierter Veranderung der Fadenorientierung beim Drapieren erfolgen. Zwecks Reproduzierbarkeit sind im Zuschnitt und in der Montage Maschinen mit CNC-Steuerung oder robotergefuhrte Verbindungstechniken, darunter Einseiten-Nahtechnik, und Handhabungstechnik notwendig. Bauteileigenschaften werden durch Montageprozesse beeinflusst. Positiv wirkt die z-Verstarkung, wahrend das Ein- und Durchstechen zur Reduzierung der In- Plane-Eigenschaften infolge der Perforation einkalkuliert werden muss.

Load‐adapted 3D‐reinforcement by means of function‐adjusted ready‐making process

Complex material requirements for high‐technology applications increasingly demand the use of hybrid material structures with properties tailored to the lines of loading. Textile‐reinforced multilayer composite structures are particularly suitable for the production of component structures in an optimised lightweight construction. In the loading case, however, delaminating phenomena occur between the individual layers due to the low interlaminar shear strength. The appropriate techniques and machines of the ready‐made‐clothing technology allow the specific sewing‐up of the semifinished textile products into a three‐dimensionally reinforced multilayer composite structure; the setting of a load‐adapted and failure‐tolerant characteristic of properties being possible in the z‐direction through a versatile variation of sewing parameters. Moreover, the sewing technology makes possible a ready‐made‐clothing‐technological preassembly of components of semi‐finished products, and thus can perform position‐fixing f...

New shielding protective equipment for live working

The new protective equipment forms a FARADAY cage, thus protecting the worker from unacceptably strong electrical fields as well as from being invaded by dangerous electric currents. The protective shielding clothing described is a personal protective equipment of the highest category. Therefore, it must be certified by an acknowledged examining and certifying authority. An application with regard to the attestation of conformity for this protective clothing hasbeen submitted to the Examination andCertification Section of the Expert Committee for Electrical Engineering.

A New Stitching Technology for Improved Thermal Insulation of 3D Nowoven Assemblies

Abstract3D fabrics are in various forms and shapes and are used in different applications of technical textiles. The functional purpose of their use is primarily to create a barrier or maintain a distance between two mediums. Fabrics from knitting or weaving machines are mostly not in their end product shape. They have to be joined with different forms of joining methods, mostly sewing to obtain its final form. Usually the conventional method of sewing compresses the 3D fabrics at points of needle insertion and the fabrics do not perform along stitch line as they perform in rest of their plane. Spacer stitching is a new joining method developed, which particularly addresses the problems related to compressions along stitch lines. Spacer stitching samples are tested with skin model and the thermal resistance along stitch line are compared with conventional lockstitch sewing method. With the help of infrared technology, thermal emissions have been studied for spacer stitching and conventional lockstitch, compared and presented in this paper.

Ready-Made Technologies for Fiber-Reinforced Plastic Composites

Ready-made technology processes are used to cut the semi-finished products from the textile fabric manufacturing processes, give them the shape of the near net-shape dry preform, assemble, and prepare them for composite material production process. This includes pattern design of the individual preform parts, nesting, and spreading as cutting preparation, as well as cutting and textile assembly of the preform by sewing, welding, and bonding. To ensure mechanical functionality of the composite component, the semi-finished products have to be selected carefully and integrated into the preform structure in the directions of forces. This has to be managed without fold formation and with only a defined change of yarn orientation during draping. In cutting and assembly, CNC-controlled machines or robot-guided handling and joining technologies, among them one-side sewing and industrial handling are required for reasons of reproducibility. Component properties are influenced by the assembly processes. Z-reinforcements are advantageous, while the pricking and piercing reduce in-plane characteristics due to perforation.