High-speed machining

High-Speed Rotary Tableting Machines High-speed rotary machines work with the same principles as all other rotary machines. They possess a huge number of punch and die sets and often two filling stations. Another possibility is to use punch and die sets which are able to produce several tablets simultaneously. Special tooling can be used for this purpose however this is not the subject of this chapter. As... 

Vibrations, sound, and noise are other examples of common industrial hazards. The most common injury because of vibration is sound-induced hearing loss. The vibrations of machines, high-speed pumps, generators, boilers, and conveyers produce unwanted sound noise. The adverse effects produced by these sounds are as follows ... 

Viscosity Glassifications. The general ISO iatemational viscosity classification system for iadustrial oils is given ia Table 4 from ASTM D2422 (American National Standard Z11.232). For high speed machines, ISO viscosity-grade 32 turbiae and hydrauHc oils are a common choice. ISO grades 68 and 100 are appHed for more load capacity ia slower speed machines where power loss and temperature rise are less of a question. 

Another development is the Inverform process and its more modem version, the Bel Bond (Fig. 8). In the Inverform unit, several pHes are formed on top of each other by consecutive, twin-wke forming units above a long carrying fabric. The Inverform process also is used for the forming of paper grades and is capable of moderately high speeds. Other versions of board machines involve mini-Fourdriniers and/or twin wkes which are placed on top of a carrying fabric. 

Single-punch machines produce approximately 100—150 tablets per minute. Depending on numbers of die per punch units, standard rotary presses can produce 5000 tablets/min, and even more with a double-sided rotary press. The newest high speed presses can achieve 12,000 tablets/min. 

High speed machines such as impact mills begin to suffer high wear rates when processing materials above Mohs s hardness 3, unless very special wear-resisting measures can be taken. 

Abrasiveness. This property is closely related to hardness in homogenous materials, but can be affected by particle shape, eg, the presence of sharp corners. In many cases a small proportion, as low as 0.5%, of a hard impurity is enough to cause severe wear to many high speed machines. 

Sometimes cemented carbide tools are used not only for hardness and wear resistance but also for high modulus or stiffness. For example, in end mills used in high speed machining of aluminum alloys, the deflection of the tool can affect the performance of the tool considerably. This includes chatter... 

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