Macaroni press

Macaroni Press. A hydraulic press with a perforated false bottom. A so-called preliminary block is placed between the piston of the press and the bottom. This block consists of NC, previously colloided in a kneading machine with solvents such as eth-alc, acet, etc, blended with other ingredients such as dipHenylamine,... 

As single base powders have been developed particularly in the U.S.A., their method of manufacture may be described as illustrating the principles involved. British practice is similar but often with omission of the macaroni pressing stage. 

Another type of extruding press is the so-called "macaroni press , used for making strands of smokeless propellants. Its use is described under "Extrusion (Fig 5)... 

This consists of blocking which involves pressing the mass for several minutes at a pressure of ca. 200 kg/cm2 (3000 lb/in2). The block thus formed is transferred to another press of a type much similar to the extrusion press (Fig. 213). Here the dough is forced through a series of screens and perforated plates. This is referred to as macaroni pressing owing to the shape of the extruded threads. 

The United States methods of solvent recovery and drying of single-base propellants are described in detail in Ref 2, pp 26-32. These operations are conducted with proplnts in the shape of final grains. Prior to this, the colloided mass of proplnt is subjected, in sequence, to action of a preliminary blocking press, a macaroni press, final blocking press, graining and cutting opns (Ref 2, pp 23"25)... 

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