Extrusion International 1-2016

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Extrusion International 1/2016 30
Bi-oriented PVC pipes
are increasing
Like PVC-U pipes, the most suitable joint system for PVC-O
pipes is a socket SICA, manufacturer of plastic pipe ma-
chinery, in 1998 patented (EP0930148) and developed a
unique socket thermoforming process for PVC-O pipes. SICA’s
patented system is characterized by forming and internal cal-
ibration of the socket on a metal mandrel. The heated pipe
end is inserted onto the metal forming mandrel when the final
thermal state of wall-thickness is uniform but varies longitu-
dinally along the pipe. The precise final thermal state is at-
tained through conductive heat transmission, without
variation of the pipe end diameter. In addition to the process,
the equipment is also protected by patent, in particular
the constructive configuration of the contact oven,
which achieves a stable and repeatable final heating.
The sockets obtained have precise internal dimensions
and a perfectly flat edge, shaped by a sliding flange on
the mandrel. Thus, no further processing of the edge is
required after the socket forming.
SICA belling machines, called STARBELL, are particularly
suitable for direct installation in extrusion lines. To date,
SICA has sold 19 Starbell machines and over 100 form-
ing mandrels, thus achieving vast experience in the field.
There are three models of STARBELL belling machines:
- STARBELL 250 for pipes up to a maximum diameter of
250 mm,
- STARBELL 500 for pipes up to a maximum diameter
of 500 mm,
- STARBELL 630 for pipes up to a maximum diameter
of 630 mm.
The machines are also suitable for stand-alone installation in
PVC-O lines.
The technical and commercial success of the STARBELL ma-
chines surely lies in their reliable and repetitive working
process, in their user-friendliness and in their strong and robust
design configuration.
Bi-oriented PVC pipes are recognized for
their considerable savings of raw materi-
als while maintaining the same mechani-
cal resistance and application in
comparison to standard PVC-U pipes.
The number of PVC-O pipe extrusion lines
is increasing in several areas of the world,
but especially in the Americas and
Australia.