Pressing multiple-action

Multiple-action pressing Multiple-action pressing systems are those that support and compact each level of multilevel parts with a separate punch or tool member. Such tooling is used to minimize density gradients in complex compacts. Therefore, all of these more sophisticated machines also use one or the other method of double-motion pressing, as demonstrated in Figure 216. With the above descriptions the figures are self-explanatory. 

Figure 216. Schematic representations of three multiple-action tooling systems. (a) Upper and lower punches pressing, die stationary, (b) Upper punches pressing, floating withdrawal die. (c) Upper punches pressing, controlled withdrawal of die and lower punches...

Multiple-action presses can have two, three, or more powered slides or actions. These various actions are independently powered and controlled to act in some predetermined sequence. 

Mushiake, H., Saito, N., Sakamoto, K., Itoyama, Y., and Tanji, J. (2006). Activity in the lateral prefrontal cortex reflects multiple steps of future events in action plans. Neuron 50, 631—641. Newell, A., and Simon, H. A. (1972). Human Problem Solving. Prentice-Hall, Englewood Cliffs, NJ. Passinsrham, R. E. (1993). The Frontal Lobes and Voluntary Action. Oxford University Press, Oxford, UK. 

Wink, M. (2007) Molecular modes of action of cytotoxic alkaloids - from DN A intercalation, spindle poisoning, topoisomerase inhibition to apoptosis and multiple drug resistance, in The Alkaloids (ed. G. CordeU), Vol. 64. Academic Press, San Diego,... 

In some chemical methods of activation, the base raw materials are plasticized by the chemical agent, and then auxiliary binders are not needed. The zinc chloride process provides an example. In a typical method, 25 parts of finely pulverized peat are mixed with 30 parts of zinc chloride in a concentrated solution. When the mass becomes plastic, it is passed through a multiple-orifice extrusion press. The spaghetti-like strings are dried and carbonized at a temperature below 700° C. Upon completion of the action, the carbon is washed with acid to remove zinc compounds and then dried. The product is suitable for solvent recovery, but when intended for gas masks it is given a supplementary activation with steam. A similar process has been developed, using phosphoric acid. 

Aircraft brakes are made up of multiple disks of carbon-carbon, comprising rotors attached to the wheel and stators attached to the brake assembly. The braking action is achieved by hydraulically pressing the disks together. Stimson and Fisher [176] have... 

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