Pressure distribution, press section

The Kawakita compaction equation is another equation which is often used for ceramic powder pressing. It can be derived by considering that compaction is similar to packing by tapping, where the compaction pressure, P, is directly substituted for the number of taps, N, in the analysis in Section 13.5.1. The Kawakita equation is a special case, where the value of m in the Weibul distribution function for tapping is 1. In the Kawakita equation, the compaction, C, defined as the relative reduction in volume is given by [72]... 

In pressure agglomeration, the distance between the surfaces of compacting tool sets specifically in extrusion, the distance between the pressure generating device and the die plate, in roller presses, the closest distance between the rollers. Double-roll pellet mill in which the rollers are in the shape of coarse, intermeshing gears with bores at the root sections between the gear teeth. (Also gear pelletizer.) Distribution plate in which the perforations are manufactured such that they produce a directional flow of gas. See melt solidification. 

As discussed in Section 8.2 (Fig. 8.3), interparticle and wall friction, force dissipation from particle to particle, and sliding under shear cause differences in density distribution in a compact that is produced in a die with one-sided compression by one of the punches. To obtain a somewhat more uniform structure, compaction can be carried out by both punches. If both move at the same rate and for the same stroke length, thus exerting identical forces, and assuming uniform filling of the die, a mirror image of the density distributions that were shown in Fig. 8.3 (Section 8.2) develops along a neutral plane which, under those conditions, is located in the middle of the compact. Machines that operate in this manner may be identified as presses with double pressure (see also below). 

---