Entex: Different planetary spindles & gearings for new extrusion processes

ENTEX has consistently pushed forward the further development of process technology and has developed not only various types of planetary spindles but also different gearings for different requirements of new extrusion processes.

In order to achieve increased service life and longer maintenance intervals, the "heavy series" of the ENTEX planetary roller extruder - compared to the standard series - is equipped with a larger gear module. Due to the larger toothing and greater planetary spindle diameter, it is called "heavy design" and designated with the abbreviation "S". Extruders of the S-series are used particularly for processes, that have very high mechanical requirements on the geared process components. For example, for the processing of highly filled elastomers and thermoplastics with filler contents of 80% and more.

Previously, the heavy series were only used for extruders with very high throughput capacities of the sizes 280 and 400, with the designation 280S and 400S. In response to demand, the company  has now added the two smaller sizes 150S and 180S to its  portfolio.

With these machine sizes, even smaller production lines for mechanically highly demanding products, as for example WPC, can be realized. Of course, the new sizes are built according to the proven modular ENTEX system and provide, as usual, the full process-technological flexibility.

For mechanically heavily loaded machines, the use of a large gearing module increases the wear resistance and load capacity of the gearing. The module of a gearing is the central parameter for the definition of the tooth geometry. The larger the module, the larger the cross-sectional area of a single tooth and the larger also the diameter of the planetary spindles if the number of teeth increases.

A large number of planetary spindles with many teeth can be inserted in the standard extruder series with the small gear module 1 to 3.5. Due to this, the number of kneading gaps as well as the exchange surface of the extrudate is considerably increased. These series are particularly suitable, for example, for the extrusion of liquids, for chemical reactions and for extrudates with low filler content.

With the heavy extruder series (S-series) with large gear module (usually module 5.5), due to the smaller number of planetary spindles with less teeth and larger diameter, there are correspondingly less but larger kneading gaps compared to the standard extruder series with the same design size. Due to the larger diameter of the planetary spindles, the S-series have a larger spatial volume inside the processing part to receive the supplied material. The significantly rougher gearing increases the stability of the toothed components. These mechanical properties make the S-series particularly suitable for processes with high filler contents and highly viscous materials such as WPC or rubber.

In order to ensure proper functioning, all components of the extruder processing part must be regularly maintained, checked for proper condition and, if necessary, cleaned or reworked in accordance with the specifications in the operating instructions. Also the wear condition of all toothed components must be measured and evaluated at regular intervals.

The service life of the toothed processing part components depends significantly on the design of the extruder (standard or S-series), the materials used for the components (standard steel, special steel, stainless steel, PEEK, etc.), the process parameters (heating temperature, material pressure, speed, torque, etc.) and of course on the material properties of the substances that are added to the extrusion process.

Breakdowns caused by insufficient or improper maintenance can cause production losses, high repair costs and long downtimes of the extrusion line. For this reason, regular maintenance - including the toothed components of the extruder - is essential.