Additive Manufacturing and Vulcanization of Carbon Black Filled Natural Rubber Based Components

Additive manufacturing of thermoplastics or metals is a well-approved sustainable process for obtaining rapidly precise and individual technical components. Except for crosslinked silicone rubber or thermoplastic elastomers, there is no method of additive manufacturing of elastomers. Based on the development of the additive manufacturing of elastomers (AME) process, the material group of rubber-based cured elastomers may gain first access to the process field of three-dimensional (3D) printing. Printing and crosslinking of rubber is separated into two steps. In the first step, printing is realized by extrusion of the rubber by using a twin-screw extruder, which works according to the derived fused-filament-fabrication principle. In the second step, the component is vulcanized in a high-pressure hot-air autoclave. Because of the plastic flow behavior of non–crosslinked rubber materials, a thermoplastic shell is probably needed to maintain the geometry and position of the additively manufactured rubber. In this way, one layer of thermoplastic and one layer of rubber are printed alternatingly until the component is finished. Afterward, the manufactured binary component is placed in an autoclave to obtain the elastomer after vulcanization under a hot-air and high-pressure atmosphere. Then, the thermoplastic shell is removed from the elastomer and can subsequently be recycled. As compared with conventional thermoplastics, the high viscosity of rubber during processing and its instable shape after extrusion are challenging factors in the development of the AME. This contribution will show a modified 3D printer; explain the printing process from the designed component, via shell generation, to the vulcanized component; and show first printed components

Distributed Control Concept for Drive Roller

In diesem Beitrag wird ein Steuerungskonzept für antreibende Tragrollen als neuartige Zwischenantriebe für Gurtförderanlagen im Bereich des Berg- und Tagebaus vorgestellt. Die Steuerung erfolgt auf zwei Hierarchieebenen über ein dezentrales Optimierungsmodell, welches die notwendigen Steuerungsparameter für den Betrieb der antreibenden Tragrollen ermittelt. Das Optimierungsmodell entsteht auf der Grundlage des experimentell untersuchten Kraftübertragungsverhaltens von antreibenden Tragrollen und wurde hinsichtlich einer schnellen und vor allem antriebsanzahlunabhängigen Anwendbarkeit weiterentwickelt.This paper presents a distributed control concept for drive roller as a novel approach for intermediate drives for belt conveyor systems in the field of mining. The control is based on a two-level, distributed optimization model which determines necessary control parameters for the operation of driven idlers. Experimentally investigated power transmission behavior of drive roller is used as an input for the distributed optimization model. The main target of the used model is a rapid solution finding irrespective of the number of drive roller