Cutting actions

Earlier on when we described the cutting action of the drill bit we learned about the drilling fluid or mud. The mud cools the bit and also removes the cuttings by carrying them up the hole outside the drill pipe. At the surface the mud runs over a number of moving screens, the shale shakers (Fig. 3.11) which remove the cutting for disposal. The fine particles which pass through the screens are then removed by desanders and desilters, usually hydrocyclones. 

For hard lormalons requinng a cutting action. Cutlers are furnished wMh induslnai chrome-plated pIna. 

These machines have distinctly different modes of action. The characteristic action of crushers is slow compression. Grinders apply impact and attrition, sometimes combined with compression ultrafine grinders function mainly by attrition. Cutters, dicers and slitters are characterized by their cutting action. 

Its chief advantages are that it is easily placed and the cutting action is positive. 

From these definitions, it can be seen that the more specific meaning of abrasion is wear by the cutting action of hard asperities. The common practice in the rubber industry of using abrasion as a general term for wear probably results from the fact that most wear tests for rubbers use the action of sharp asperities, for example abrasive paper, to produce wear. 

In no model pheromone biosynthetic system is the molecular mechanism of hormonal regulation completely understood. The mechanism of action of JH and the nature of its receptor remain one of the mysteries of insect science, and the clear-cut action of JH by itself in inducing specific genes in pheromone production in bark beetles offers an excellent model for study. A better understanding of the PBAN receptor and the second messenger system it triggers as well as the steps regulated in pheromone biosynthesis is also needed. The next several years should see some of the key questions answered in model insects. 

Due to their cutting action (which differs from the Menghini technique), Vim-Silverman and Tru-cut needles produce a sufficiently large and almost intact cirrhosis tissue sample. As a consequence, the false-positive results can be brought down to below 10%. Nevertheless, the risk of subsequent bleeding is clearly higher. For this reason, the diameter of the needle should not exceed 1.6 mm. 

High detonation speed will give a shattering or a cutting action low speed will result in a heaving action. 

Figure 12.5. The generation of wood chips (Koch, 1964). (a) Planermills produce shavings of variable geometry, (b) A hammer hog reduces coarse material, (c) The cutting action of chipping knives, (d). A disc chipper.

Figure 12.6. The generation of flakes, (a) Cutting action of a knife-ring flaker (Fisher, 1974). (h) Typical distribution of flake thickness (Jager, 1975) (c) Cutting action of a large drum flaker (courtesy Pallmann, Zweibmcken, Germany), (d) Ring refiner (Fisher, 1972).

Mining work requires specialized tools to perform work under the harshest and most aggressive conditions. This is when diamond abrasive properties combined with the hardness properties of other materials become crucial to drilling or cutting action that is subjected to extreme loading during prolonged periods. 

Fig. 20 Schematic showing the cutting action of the SM2000 cutting mill. (Courtesy of Retsch, Inc., Newtown, PA.)...

Fig. 8.11 Basic cutting action and chip formation, redrawn and adapted from [77]...

Included in the concept of the abrasive profile is the real-time change in its effective force profile due to byproduct accumulation. Various rotational and rinsing schemes have been developed to reduce the byproduct accumulation effects that would otherwise reduce the diamond s effective cutting action. 

These machines do their work in distinctly different ways. Compression is the characteristic action of crushers. Grinders employ impact and attrition, sometimes combined with compression ultrafine grinders operate principally by attrition. A cutting action is of course characteristic of cutters, dicers, and slitters. 

---