All models of the PXT Riser® are based on a highly exothermic riser body. This corresponds to either tried and tested THERMO Risers® or classic caps. The riser body is connected to the casting via a metal sleeve which is pressed into the side walls of the riser body.
The riser body compresses the moulding material underneath identically to the rest of the pattern contour when used on high-pressure moulding machines. In this way, both overpressing and too soft moulding material are avoided. At the same time, the connection between the riser body and the metal sleeve is virtually relieved of any pressure.
The PXT Riser® rests on the metal sleeve and the vertical compaction pressure is converted by friction having only minimal impact on the riser material and the moulding material compaction underneath the riser body.
Another feature of our PXT Risers®: a pre-drilled hole in the riser body and a rigid mandrel connected to it, which provides ventilation. The riser geometry allows for a very robust design of the mandrel. This has the advantage that the mandrel does not deform – not even under lateral forming forces.
In addition, the moulding material underneath the PXT Riser® absorbs almost the entire forming pressure – in place of the metal sleeve. As a result, only slight frictional forces act on the riser body. This prevents riser pieces from breaking off or crumbling during moulding, which in turn minimises the occurrence of surface inclusions.
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