Standard_Parts_Catalogue

Page 2158 | Material Characteristics Material Characteristics of Plastics Materials and Elastomers Information The above details are general values without claiming to be complete. Material properties may vary widely through addi- tives, modifications and environmental influence factors. The details are unsuitable as the sole basis for constructions. The data may not be used in place of tests to determine the suitability of a material for a specific purpose. No warranty or liability will be accepted fort the above specifications and details. Duroplast Technopolymer Elastomers This group includes plastic materials which solidify by chemical reactions. They closely crosslink into spatial lattice patterns of macromolecules which gives Duroplast material high mechanical strength and surface hardness. Their elasticity is low, how- ever. The curing process is irreversible. Un- like Technopolymer, Duroplast can- not be melted because it is rigid up to degradation temperature. Phenolic resins are among the most commonly used Duroplast materials. In general, the molecular crosslinking of Duroplast creates good chemical stability. The coloring options of components made of Duroplast are limited. With increasing temperature and once the softening point is exceeded, this group of Technopolymer melts, can be heat distorted and solidifies again after cooling. This process can be repeated any number of times. Un- like Duroplast, there is no chemical reaction during processing. Technopolymer materials can be sub- divided into amorphous and partially crystalline plastics. The disordered structure of amorphous materials al- lows the production of transparent components by injection moulding right through to crystal-clear parts. Partially crystalline Technopolymer have a structure resulting in enhan- ced mechanical properties and tem- peratures of use. The wide variety of different Tech- nopolymer and their options of mo- difications allow the production of “tailor-made” construction materials with respect to mechanical proper- ties, chemical resistance, tempera- ture resistance and different colors. A feature of elastomers is that they can be deformed under minimal ten- sile or compressive stress. When the force effect decreases or no longer exists, the parts automatically return to their original, undeformed shape. Thus, they demonstrate the typical behavior of rubber. In chemical terms, these are macro- molecules which are interconnected by only a few chemical crosslinking bridges. With thermoplastic elastomers, the cross-links soften under the influence of heat, thus demonstrating a thermo- plastic behavior. By way of modification, elastomers can be made in varying degrees of hardness. They can be dyed easily by adding color pigments. Material characteristics of Elastomers → Page 2162 ff.