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Der Verein für Gerberei-Chemie und -Technik (VGCT) wurde 1949 zur Förderung wissenschaftlicher und technischer Forschung, zum Zwecke des fachlichen Erfahrungsaustausches sowie zur Förderung des beruflichen Nachwuchses gegründet. Gegenwärtig hat er ca. 300 Mitglieder, welche sowohl einzelne Personen als auch Firmen sind. Im VGCT treffen sich Ledertechniker, Maschinenbauer, Chemiker und andere am „Ledermachen“ interessierte Menschen zum Austausch und zu gemeinsamer Arbeit. Der Verein bietet eine Plattform für den fachlichen Austausch indem er jährliche Fachtagungen und fachliche Kooperationen in firmenübergreifenden Arbeitsgruppen (Kommissionen) organisiert, technische Veröffentlichungen in der Fachpresse mit eigenen Seiten fördert und sich aktiv an Umweltschutz, Arbeitssicherheit sowie Gesundheitsschutz beteiligt. / The Association for Chemistry and Technology in Tanning (VGCT) was founded in 1949 in order to facilitate scientifi c and technical research and exchange of professional experience as well as to promote young talents. Currently it has some 300 members – single persons as well as enterprises. In the VGCT, leather technologists, mechanical engineers, chemists and other people interested in “making leather” meet in order to exchange ideas and work together. The association offers a platform for sharing professional experience by organizing annual meetings and professional co-operations in groups from across various companies (commissions), by facilitating technical publications in specialist press with own pages and actively participating in environmental protection, occupational safety and health protection.

Der Verein für Gerberei-Chemie und -Technik (VGCT) wurde 1949 zur Förderung wissenschaftlicher und technischer Forschung, zum Zwecke des fachlichen Erfahrungsaustausches sowie zur Förderung des beruflichen Nachwuchses gegründet. Gegenwärtig hat er ca. 300 Mitglieder, welche sowohl einzelne Personen als auch Firmen sind. Im VGCT treffen sich Ledertechniker, Maschinenbauer, Chemiker und andere am „Ledermachen“ interessierte Menschen zum Austausch und zu gemeinsamer Arbeit. Der Verein bietet eine Plattform für den fachlichen Austausch indem er jährliche Fachtagungen und fachliche Kooperationen in firmenübergreifenden Arbeitsgruppen (Kommissionen) organisiert, technische Veröffentlichungen in der Fachpresse mit eigenen Seiten fördert und sich aktiv an Umweltschutz, Arbeitssicherheit sowie Gesundheitsschutz beteiligt. / The Association for Chemistry and Technology in Tanning (VGCT) was founded in 1949 in order to facilitate scientifi c and technical research and exchange of professional experience as well as to promote young talents. Currently it has some 300 members – single persons as well as enterprises. In the VGCT, leather technologists, mechanical engineers, chemists and other people interested in “making leather” meet in order to exchange ideas and work together. The association offers a platform for sharing professional experience by organizing annual meetings and professional co-operations in groups from across various companies (commissions), by facilitating technical publications in specialist press with own pages and actively participating in environmental protection, occupational safety and health protection.

Textile structures made of biocompatible, osteoconductive and resorbable chitosan-filaments provide excellent preconditions as scaffolds for Bone Tissue Engineering applications. The novel Net Shape Nonwoven (NSN) technique that enables short fibers to be processed into three-dimensional net-shaped nonwoven structures with adjustable pore size distributions is described. NSN scaffolds made of pure chitosan fibers were fabricated. NSN hybrid scaffolds for improved initial cell adhesion were realized by combining the NSN technique with electrospinning and dip-coating with collagen, respectively. Scanning electron microscopy and liquid displacement porosimetry revealed an interconnecting open porous scaffold structure. The novel chitosan-hybrid scaffolds provide proper conditions for adhesion, proliferation and differentiation of the seeded human bone marrow stromal cells, proving that they are suitable for usage in hard-tissue regeneration.

The availability of a considerable amount of waste carbon fiber (CF) and the increased pressure to recycle/reuse materials at the end of their life cycle have put the utilization of recycled CF (rCF) under the spotlight. This article reports the successful manufacturing of hybrid yarns consisting of staple CF cut from virgin CF filament yarn and polyamide 6 fibers of defined lengths (40 and 60 mm). Carding and drawing are performed to prepare slivers with improved fiber orientation and mixing for the manufacturing of hybrid yarns. The slivers are then spun into hybrid yarns on a flyer machine. The investigations reveal the influence of fiber length and mixing ratio on the quality of the card web, slivers and on the strength of the hybrid yarns. The findings based on the results of this research work will help realize value-added products from rCF on an industrial scale in the near future.

In order to advance consistent lightweight construction principles in automotive and mechanical engineering, support frame construction made from high-performance materials is becoming more commonplace. These consist of complexly structured nodular connection elements. The required connection elements have not yet been produced satisfactorily. The developed node element structures in this paper are produced on a shuttle weaving loom by flattening and weaving them as multi-surface woven fabrics. The development of the woven concept for the realization of node element structures is based on the fragmentation of the individual sub-elements. The goal of this research is development of a flexible technology for weaving fabrics and intended for the integral realization of woven nodular semi-finished products with complex geometries and connections, which are to be used to connect Fiber-reinforced Plastic components in support frame structures.

Role of silane-treated stöber silica as reinforcing filler for nitrile rubber (NBR) has been studied. Stöber silica is synthesized by sol–gel method, and the surface of silica is modified with the treatment of silane-coupling agent viz. γ-mercaptopropyltrimethoxysilane (γ-MPS) in varying proportions. Average particle size of stöber silica of spherical shape in the range of 200 to 400 nm is evident from scanning electron microscopy (SEM). Surface modification of silica particle with silane-coupling agents decreases surface energy and reduces agglomeration of silica particles in rubber matrix. Stress–strain study and dynamic mechanical analysis of silica-filled composites are compared with the unfilled ones. Analysis of cross-linking density, mechanical properties, and storage moduli indicates a strong rubber–filler interaction in the silane-treated, silica-filled NBR composites. Silane treatment is found to be effective in uniform dispersion of silica in rubber matrix and in improving the mechanical properties of rubber composite. Different functionalities of organosilane at its both end improve the compatibility of silica with rubber matrix and offer better rubber–filler interaction.

A novel constitutive characterization method for uncured rubber behaviour has been developed in this article. A systematic measuring procedure was designed to fully investigate the uncured rubber complex stress–strain behaviour under different deformation patterns, which integrated three kinds of tests – the uniaxial tensile, the compression test and the shear test. It can be found from the observed behaviour that the uncured rubber has similar but much pronounced non-elastic stress–strain relationship, which is highly non-linear and highly rate dependent. A generalized Maxwell model with modified Yeoh model is developed to constitutively describe the observed phenomena in which parameters are identified by an evolution optimization scheme. Good agreement can be found between the model and the test data. Another finding is that, similar to vulcanized rubber, multi-test data are needed to obtain compatible constitutive models. The test results, findings and the developed model help rubber engineers deeply understand the uncured rubber’s mechanical behaviour and provide a base for rubber manufacturing simulation.