Thomas Stegmaier

Effect of fibrous filter properties on the oil-in-water-emulsion separation and filtration performance.

Separation of secondary emulsions of dispersed droplet size less than 10 μm, by means of fibrous medium is a very complex but important process. The study investigates the influence of thin fibrous filter properties, i.e. surface energy, pore size and porosity on the separation performance of an isooctane in water emulsion (0.2%, mean drop size 2 μm). Experiments were carried out on five different filter media with a wide variation in their pore size (2-51 μm), surface energy (14-46 mN/m) and porosity (0.46-0.87) at similar process conditions. Filter media with different wettability are obtained by applying various hydrophobic and hydrophilic coatings. All the used coatings contain nanoparticles (25 nm) to impart nanoscale surface roughness at the single fiber surface. Besides emulsion properties and operating conditions, the phase separation mechanism and performance highly depends on pore size, surface energy and porosity of the filter media. More complete coalescence takes place at reduced pore size and at a surface preferentially wetted by the dispersed phase. Whereas when the pore size equals to the influent droplet size, then the surface wettability of filter is less effective and the separation mechanism is governed by inflow velocity. The emulsion inflow velocity and pressure drop are significantly affected by the filter media air permeability but do not depend on filter surface energy.

Bionic developments based on textile materials for technical applications

Abstract: Developments in the production of self-cleaning textiles based on the ‘Lotus Effect’ are presented and topical bionic research activities being undertaken in this area at ITV Denkendorf are described. The biological models have been analyzed in detail to allow definition of the construction requirements and tube-filter development, assembly of filtration test equipment and determination of characteristic filtration data. A general model for lightweight tubular structures with high bending stiffness was defined, and this formed the basis for studying potential industrial applications, including solar-thermal materials that mimic the pelts of polar bears for use in energy technology.

Self-cleaning textiles using the Lotus Effect

Abstract: The self-cleaning property of the lotus plant, named the ‘Lotus Effect’, is based on the specific properties of micro- and nanostructured ultrahydrophobic surfaces, which are always completely cleaned by rainfall: the contact area of water and dirt particles is largely minimized by the double structured surface. Methods to test superhydrophobicity and self-cleaning, which differentiate between conventional soil-repellent finished textile samples and textiles that are finished with products that impose nano-dimensional structures on the fibre surface, are described. The effect of the nanostructure on the ‘Lotus Effect’ is investigated and applications, including architectural textiles, and future trends are outlined.

15 – Nanotechnologies for coating and structuring of textiles

Publisher Summary Fiber-based materials in technical applications are an increasing worldwide market and cover a wide area. Interesting applications for fibers with nanoscaled dimensions or nanostructured surfaces are in mobility, gas and liquid filtration, fiber reinforced materials, and protection and professional protective clothing. Nanotechnology is considered to increase the number, variety, and effectivity of physical properties of existing products and, therefore, act as an innovative base for new products. There are many ways to implement nano-scale controlled properties into textiles. One is to give the fiber itself a nano-scale by fiber spinning. With novel fiber spinning technologies, it is possible to spin fibers with diameters between 20 and 500 nm; 10–500 times thinner than fibers spinnable by traditional fiber spinning techniques. The aim is to make the production of fibers with diameters below 100 nm highly productive and state-of-the-art. In order to achieve effects from nanostructures in the fiber bulk, either nanoparticle-filled polymer melts or nanophase-separating polymeric systems can be spun. Nanofillers such as clay have been known for decades, but the processing of those filled polymeric melts is challenging because agglomeration has to be avoided and the influence of nanoparticles on rheological properties can be great.

Environmentally friendly plasma technologies for textiles

Abstract: Plasma technologies present an environmentally friendly and versatile way of treating textile materials in order to enhance a variety of properties. This chapter begins by presenting the technologies of atmospheric pressure plasma. It then gives some examples of applications, before describing the environmental benefits of plasma treatment.

Woven and knitted fabrics used in automotive interiors

After an introduction to the demands of automotive textiles, an overview is given of the different types of textile components in car interiors and of market data of textiles in the automotive production. Details are given of the construction of woven, flat and 3-D knitted fabrics and of the finishing process with lamination to multilayer systems.

Innovative Developments in Fiber Based Materials for Construction

Fiber based materials for construction are in a continuous development. Due to the progress in polymer science and knowledge in process engineering important properties can be improved continuously or sometimes in great steps.

Haftverbesserung bei Textilbeschichtungen durch Plasmaaktivierung

Die kritischen Schadensereignisse Delamination und Ablosung verklebter Verbindungen gilt es auch bei textilen Produkten zuverlassig zu vermeiden. Moglich ist dies durch den Einsatz einer modifizierten Coronatechnik. Anhand ausgewahlter Beispiele lasst sich ihr Haftungssteigerungspotenzial bei Beschichtungen und Laminaten auf textilen Flachen demonstrieren.