Mixture Recipe Research Articles

Determination of the Expansion Process of Cellular Rubber Materials

Cellular rubber profiles offer a high saving potential with respect to component weight, material consumption and production costs. The foam structure is generated using chemical blowing agents. The blowing agents are incorporated into the rubber mixture before processing. The expansion takes place concurrently to the vulcanisation reaction in the curing unit. Both processes are influenced by modification of the mixture recipe. The adaptation is one of the most challenging steps in rubber processing. Currently, the expansion of rubber mixtures is analysed using modified vulcameters. However, this method is subject to several limitations. Therefore, IKV developed a new measurement system. It allows the analysis of the free expansion behaviour of a rubber sample. Based on the Archimedean principle, the time dependent foaming process of rubber mixtures is recorded. A cell structure is generated, which can be analysed using digital image processing. In the first experiments, several components of the rubber mixture are analysed using the measuring device in order to identify and categorise influencing parameters. The primary objective of further investigations is the analysis of the mixing process. In addition, verification of the results by comparison of the cell structures with industrially foamed rubber materials is planned.

Influence of fly ash and silica fume on the consistency retention and compressive strength of concrete subjected to prolonged agitating

Good workability at construction site is essential for high quality concrete since concretes of bad workability are prone to yield low strength and poor durability properties since placement and consolidation procedures cannot be performed properly. Nevertheless, this is what usually encountered in practice because slump loss is indispensable particularly when long delivery times are the case. This would be more pronounced when mineral additives are incorporated into the concretes. In this study, concretes of C25/30 class with fly ash and silica fume were produced and slumps were measured with time elapsed. At the end of each agitating period, the slumps of the mixtures were restored to the initial slumps using a superplasticizer and specimens were thereafter prepared for strength measurement. The effectiveness of using fly ash and silica fume in concrete in relation with slump loss was sought by determining the amount of superplasticizer used. Regardless of the mixture recipe, it can be concluded that as the total amount of cementitious materials increases in the concrete mix of the same initial slump, the slump loss with the elapsed time decreases.

Applications of Multicriteria Analysis in Cotton Mill

This paper presents original software called STAT-ADM (Statistical Analysis with Multicriteria Decision), developed to design and optimize the fiber mixtures in cotton mills. STAT-ADM has deep technological implications in raw material costs and facilitates the use of a flexible technological process adaptable to mixture recipe changes, reacting promptly to the yarns market demands.

Process optimization of preparing spherical titania colloids with uniform distribution using artificial neural networks

Optimal operating variables for preparing submicron uniform titania colloids were estimated using the artificial neural networks (ANN) modeling and the process optimization algorithms. Titania colloids were synthesized by a sol–gel method using mixture recipes of titanium tetraisopropoxide (TTIP), NH 3, and H 2O with ethanol/acetonitrile under temperature-controlled conditions. Different sets of the operating variables, such as [NH 3], [H 2O], and reaction temperature, were selected within an operating range to carry out Design of Experiment to evaluate the prepared particle size (PS) and the particle size distribution (PSD) data. The relationship between the operating variables and PS and PSD of the prepared samples can be constructed by an ANN modeling approach. The built ANN model was then used to predict PS and PSD values corresponding to the operating variables. The optimal operating conditions to fabricate different PS values with narrow PSD were determined by the ANN model with the optimization method. Meanwhile, the monodispersed colloids between 150 and 400 nm were fabricated using the determined optimal operating conditions.