Spiral disk extruder

Multi screw extruders Gear pumps Planetary gear extruders Multi (>2) screw extruders Spiral disk extruder... 

Several modifications have been proposed to improve the performance of the elastic melt extruder. Fritz [43] suggested incorporation of spiral grooves to improve the pressure generating capability, essentially combining the elastic melt extruder and the spiral disk extruder into one machine. In Russia [47], several modifications were made to the design of the elastic melt extruder. One of those combined a screw extruder with the elastic melt extruder to eliminate the feeding and plasticating problem. Despite all of these activities, the elastic melt extruder has not been able to acquire a position of importance in the extrusion industry. 

There are several extruders that do not use an Archimedean screw for transportation of materials, but still belong to the category of continuous extruders. These machines are sometimes referred to as screw-less extruders. Usually they employ a disk or a drum. Most disk extruders are based on viscous drag transport principle. To this category belong stepped disk extruders [Westover, 1962 Raleigh, 1879], drum extruders, spiral extruders [Ingen Housz, 1975], diskpack extruder [Tadmor, 1979, 1980 Tadmor et al, 1979, 1983 Hold et al., 1979 Valsamis, 1983], and many others. 

Purpose of the screens is primarily twofold (1) to change the melt s spiraling motion, caused by the screw rotation and (2) to filter contaminants out of the melt. Most plastics contain contaminants and these particles can be conveniently removed by means of a screen placed after the extruder barrel and before the melt flow reaches the extrusion die. The simplest means for filtering plastic melts are woven wire mesh disks of about the same diameter as that of the extruder barrels. Several... 

Extruder, Elastic-Melt n (elastodynamic extmder) A type of extmder in which the material is fed into a fixed gap between stationary and rotating, vertical disks, is melted by frictional heat, and flows in a spiral path toward the center of rotation, from which it is discharged into a secondary device that can develop the high pressure required for extmdate shaping. Only mbbery polymers with certain viscoelastic properties are suitable for the process. 

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