Bi-oriented PVC pipes are recognized for their considerable savings of raw materials while maintaining the same mechanical 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.
Like PVC-U pipes, the most suitable joint system for PVC-O pipes is a socket SICA, manufacturer of plastic pipe machinery, 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 calibration 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 longitudinally along the pipe. The precise final thermal state is attained 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 forming 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 machines surely lies in their reliable and repetitive working process, in their user-friendliness and in their strong and robust design configuration.