An apparatus for reheating and conditioning an elongate preform for forming a blow molded container, said apparatus comprising: a receiver including an elongate annular non-cylindrical inner surface portion, wherein the surface portion defines a cavity and is adapted to engage with an elongate outer surface of an elongate preform to transfer heat thereto by conduction from said surface portion, wherein the surface portion includes a three-dimensional relief to provide substantially non-uniform contact between the receiver and the elongate preform; and means for heating said receiver.

Methods for manufacturing thermoformed objects are provided. In some embodiments, a method includes controlling a material transport system to move a material to a first location proximate to one or more heat sources. The method can include controlling the one or more heat sources to heat a first region of the material to a first temperature and heat a second region of the material to a second temperature. The method can also include controlling the material transport system to move the material to a second location proximate to an object forming element, and controlling the object forming element to form a dental appliance from the material.

An orthodontic appliance made by a thermal forming process is provided. The thermal forming process can include heating a thermoformable material using a plurality of independently controllable heat sources. The plurality of independently controllable heat sources can produce at least one overlapping heating zone. The thermal forming process can further include monitoring one or more temperatures from a plurality of temperature sensing elements operably coupled to different areas of the thermoformable material. The thermal forming process can further include adjusting power of one or more of the plurality of independently controllable heat sources based on the one or more monitored temperatures such that each of the different areas of the thermoformable material reaches a respective desired temperature. The thermal forming process can further include disposing the heated thermoformable material over at least a portion of a mold to form the orthodontic appliance.

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.

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.