A system is for thermoregulating metal rotating cylinders in applications relating to plastic film converting and extruding systems, for multiple raw polymer materials. In particular, a heating system is for a rotating cylinder, e.g., a roller of a calender or a roller of a stretching unit. The heating system is an electromagnetic induction system.

A method of producing a resin container includes injection-molding a resin intermediate molded body of bottomed cylindrical shape as a first injection-molding, injection-molding a resin material outside the intermediate molded body as a second injection-molding, to produce a multilayer preform in which a resin layer is layered on an outer peripheral side of the intermediate molded body, and blow-molding the preform in a state of containing residual heat from injection-molding to produce a resin container having a bottom portion thicker in wall thickness than a body portion. A portion of the inner peripheral side of the intermediate molded body, the portion reaching a bottom portion of the intermediate molded body, has a tapered region in which the wall thickness increases toward the bottom portion.

A heating system (2) for heating plastic material preforms upstream of a blow molding or stretch-blow molding machine (3), the system comprising a heating module (4) adapted to be crossed by a plurality of preforms (5) advancing along a transport line (14), wherein the heating module (4) is provided with a plurality of heating elements (12, 13) arranged along a plane substantially parallel to a plane containing the axes of the preforms adapted to cross said heating module, wherein the heating module (4) comprises a first heating zone (10), proximal to a support area of the neck of the preforms and comprising at least one first heating element (12) of said plurality of heating elements, and at least one second heating zone (11), arranged adjacent to said first heating zone (10) and at a passage zone of the tubular body of the preforms, and comprising at least one second heating element (13) of said plurality of heating elements, wherein the heating system (2) further comprises at least one first temperature sensor (8) arranged externally to the heating module (4) and at said first heating zone, and at least one second temperature sensor (9) arranged externally to the heating module (4) and at said at least one second heating zone.

An Infrared heating system (101) designed for the efficient heating of preformed plastic tubes (106). The system comprises an infrared housing unit with multiple longitudinal strips (107N) of infrared heating elements (103), surpassing the length of the preformed tubes. A handling arrangement involving a series of rollers (202) facilitates the simultaneous oscillation and rotation of the plastic pipes. The inner surface of the infrared housing (102) features strategically positioned reflectors (109N) to enhance the infrared heating effect. The handling arrangement includes longitudinally spaced motorized rollers for axial movement, and motorized wheels (110) and tracks (111) for transverse movement. The infrared housing unit offers multiple temperature zones to suit the characteristics of the plastic pipes and employs temperature sensors (114N) for uniform and precise temperature control. A corresponding process for heating preformed plastic pipes is also described, integrating these features for effective and controlled heating.