Elastomeric compounds, characteristic

Unfortunately, at the present time there does not appear to be a detailed understanding of the relationship between the properties of the raw materials or the ingredients making up an elastomeric compound and the compound s processability. Therefore, the most widely used approach presently being adopted is to use the conventional characteristics with the standard specification limits issued by the supplier or special agreed upon limits with the supplier to accommodate specific requirements in the fabricators manufacturing process. 

Press control is critical it is essential that the elastomeric compound reaches the required cure state to optimize product performance yet remains in the press the shortest time period to maximize productivity. To meet this objective, both compression and injection presses now use microprocessor controls, which enable variations in platen temperatures and compound cure characteristics to be accommodated without sacrificing product performance or productivity. 

Ozone (03) - An allotropic form of oxygen. A gas with a characteristic odor which is a powerful oxidizing agent. It is present in the atmosphere at low levels and causes cracking in certain types of elastomeric compounds when they are stretched or compressed. 

Whereas the initiation of fracture appears to be a similar process for all elastomers, the propagation of a crack is widely different. Three basic patterns of crack propagation, or tearing, can be distinguished corresponding to three characteristic types of elastomeric compounds ... 

Compounded polymers prepared with thermoplastic elastomers (TPE) are prepared in much the same manner as thermoplastics, with some exceptions. Thermoplastic elastomers generally combine the flexibility and frictional behavior of mbber compounds with the practical forming considerations of thermoplastic materials. These are commonly encountered in automotive and appliance applications where non-slip surfaces are desirable. Since compounds in this class have elastomeric physical characteristics, this often requires that a twin-screw mixer makes use of... 

A number of synthetic rubbers and elastomeric materials have been developed with special characteristics that extend the overall usefulness of the elastomers for corrosion-resistant equipment. In addition, polymers of ethylene and propylene have been developed with elastomeric properties. Like natural rubber, each of these may be compounded in several ways for maximum resistance to specific chemical exposures. Natural rubber and other elastomers are frequently used in combination with brick linings for temperature conditions that are above those allowed for elastomer material alone. They have proved to be excellent membrane linings for such construction. 

In order to describe rubber compounds from the point of view of their processing capabihty different methods are used [29]. In this respect full characterization is achieved by analyzing the flow curves of rubbers and rubber compounds. The flow curves can be obtained by different viscometers. In the rubber industry (over 100 years) a technological index has been widely used - the Mooney viscosity. It serves for a comparison and control. It is measured relatively quickly with the respective viscometer and in accordance with the International standard ISO 289-1 2002. The obtained Mooney viscosity gives information just for one point of the flow curve of the rubber or rubber compound and this is the reason that no full rheological characteristics of the elastomeric material are obtained [30]. In order to describe the processing capability of rubber compounds by means of Brabender Plasticorder, the measurements are usually performed at a relatively high... 

Elastomeric isolation bearings are devices that make use of the flexibility of natural or synthetic mbber compounds to achieve the characteristics necessary for an effective isolation system. Such bearings have been widely used in bridge applications since the early part of the twentieth century to accommodate translational and rotational movement resulting from thermal expansion while supporting the weight of the deck (Fig. 3). 

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