Upright extruders

Upright extruders. The upright extruder was the very first type of extruder in operation (see also chapter 4), but this was soon replaced by the horizontal version initially to simplify material feed. 

Vertical extruders (suspended extruders). The vertical extruder was very quickly adopted early on for the extrusion of certain products, in particular for stoneware pipes and large size slugs, also for certain shapes of roofing tiles and small items in the advanced ceramic industry. Favoured by the vertical outlet, the column can easily be removed without the risk of being deformed. As the products were extruded in an upright manner the machine was also often incorrectly referred to as an upright extruder. 

There were essentially two reasons for the transition from an upright to a horizontal auger extruder feeding of an upright extruder, which at that time was still effected manually, was extremely strenuous, and the arrangement of the drive - whether at top or bottom - was not without problems. 

On the other hand the upright extruder with its vertical outlet was beneficial inasmuch as the bricks produced on this machine hardly showed any noticeable laminations created by the auger and the flow movement of the clay. The clay pushed to the bottom was taken along towards the die by the rotating base and was forced to exit laterally. As a result of the change in direction, the previous longitudinal orientation of the clay material was converted to a crosswise orientation. As the clay strings were still turned inside the extruder, any laminations which may have been caused by the flow motion of the material were hardly visible in the extruded column and hence the vertical extruder produced virtually lamination-free bricks. 

Frequently expression rolls were combined with an upright or horizontal pug mill or with an inclined-fitted auger extruder, so as to utilize the mixing and homogenising effect of these machines, which of course could not be achieved by the expression rolls (Fig. 7). The first vertical expression... 

Animals provided driving power for the first upright auger extruders. Initially this was in the form of direct drive using a tie beam that was fastened in a beam shoe at the top end of the auger shaft. This system of drive was... 

Fig. 40 Upright auger extruder with bottom drive using transmission and steam engine...

Cotto. Traditional Italian tiles, extruded as split tiles from weathered shaly red or yellow clays of Tuscany or Emilia. The tiles are given a rustic finish by wirebrushing or sandpapering after drying, then fired set upright using special steel kiln furniture. Tiles up to 61 cm square are produced. 

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