A method for operating a heating device for thermal conditioning preforms made of a thermoplastic material in which each respective one of the preforms is prepared for a subsequent forming process during which the preforms are formed into containers with a forming fluid fed under pressure into the preforms. The heating device is operated in at least a first operating state and a second operating state. The second operating state is a startup phase of the heating device during which a temperature of the heating device approaches an equilibrium temperature of a thermodynamically stable equilibrium state of the heating device. The first operating state is a continuous operation state following the startup phase. The second operating state is operated with a heating output value that varies over time. Furthermore, the invention relates to a heating device and a machine having a heating device, which are configured to implement the method.

According to the present invention, in order to improve the productivity of an injection stretch blow molding machine, when a core mold is lifted during mold opening at an injection molding part of the injection stretch blow molding machine, stress is dispersed so as not to concentrate at an area where the thickness changes between a preform opening and a preform body so that the preform body is inhibited from being lifted at a skin layer formed in the area where the thickness changes between the preform opening and the preform body. In a preform (30) where a skin layer (34) at the surface has a lower temperature than a middle layer (35) so as to allow a preform body (32) and a preform bottom (33) to expand and deform from the inside of the preform toward the outside of the preform, the skin layer (34) bridging between the inner surface of the preform body (32) and the inner surface of the preform opening (31) is formed in a tapered shape that opens upward at an outward slant with respect to an extension line (38) of the inner surface of the preform body (32) extending above the skin layer (34) so that, during the lifting of the core mold, the stress exerted from the preform body (32) is dispersed at a stress dispersing plane section (39) formed with the skin layer (34).

Provided is a method for heating plastic preforms, wherein the plastic parison are transported along a predetermined transport path and are heated during this transport, wherein at least one first heating section with at least one first heating element as well as at least one second heating section with at least one second heating element is arranged along the transport path, by a first temperature measuring device an actual temperature of the plastic preforms is measured in or before a start region of the transport path, and as a function of this actual temperature of the plastic preforms the at least one first heating element is controlled in such a way that the plastic preforms reach a predetermined target temperature after heating by this at least one first heating element.

A manufacturing apparatus for manufacturing a resin container, the manufacturing apparatus includes an injection molding part, a temperature adjustment part, a blow molding part, a take-out part, and a rotation plate. The temperature adjustment part includes a first temperature adjustment mold into which the preform is inserted, the first temperature adjustment mold being configured to cool the preform from an outer surface of the preform, a second temperature adjustment mold into which the preform is inserted, the second temperature adjustment mold being configured to cool the preform from an inner surface of the preform, and wherein, in the temperature adjustment part, the preform is cooled so that at least the outer surface temperature of the preform is lowered within a temperature range from 10? C. to 50? C. as compared to the outer surface temperature of the preform when the preform is carried into the temperature adjustment part.

A stretch blow molding process for producing a plastic container from a preform, having an elongated, tubular preform body, extending along a center axis. The first end of the preform body is closed by a preform bottom and the second end is adjoined by a neck part with a pouring opening. A wall, bounds an interior space of the preform. The preform body is heated and introduced into a cavity of a blow mold. A stretching mandrel enters the preform until the stretching mandrel tip reaches the preform bottom. The preform body and the preform bottom are stretched by the stretching mandrel. The preform body and the preform bottom are deformed by introducing a fluid into the preform under pressure. The stretching mandrel makes contact with the inner side of the wall in the region of the preform body.

A foamed and stretched plastic bottle having, in the body portion thereof, a foamed region in which foamed cells are distributed, wherein, in at least a portion of the foamed region, the lengths of the foamed cells in the axial direction of the bottle are so distributed as to gradually decrease as the positions of the foamed cells shift from the outer surface side of the body portion toward the central portion thereof and then gradually increase as their positions shift from the central portion thereof toward the inner surface side thereof. The foamed and stretched plastic bottle of the invention exhibits excellent light-shielding property.

A composite foamed container forming, in the body portion, thereof, a foamed region in which foamed cells are distributed, the foamed region including a first gradationally foamed region A having a gradational distribution of the foamed cells of which the length in the direction of maximum stretch gradationally decreasing from the outer surface side of the body portion toward the inner surface side thereof and a second gradationally foamed region having a gradational distribution of the foamed cells of which the length in the direction of maximum stretch gradationally decreasing from the inner surface side of the body portion toward the outer surface side thereof. The container has a large resistance against the pressure exerted on the outer surface, good liquid-dispelling property and, at the same time, has improved appearance and heat resistance.

A method for heating a preform that is rotationally symmetric about its longitudinal axis, has a standard thread, and is made of a thermoplastic material. During heating, the preform is temperature conditioned to be formed into a container having a non-circular cross-section transverse to a longitudinal axis of the container by blow-molding. The preform is provided with a temperature profile along a circumference of the preform such that areas of the preform are differentially heated in a radial direction of the circumference of the preform. The standard thread of the preform is aligned in a predefined target position before the areas of the preform are differentially heated. The preform is rotated into alignment. An alignment element engages in the standard thread of the preform and thereby prevents further rotation of the preform as soon as the alignment element comes in contact with a predetermined contact surface in the standard thread.

A method of sub-ambient pressure processing of blow-molded polymer foams and skin-over-foam sandwich panel configurations for lightweight components having improved structural properties. The method can create either skinned or un-skinned foams that offer smooth interior and exterior surfaces, zero or controlled surface porosity, skins of pre-defined thickness, and foam cells that are expanded and oriented normal to the material plane, effectively spherical or polyhedral in nature, and offering improved bending and compressive strength.

The invention relates to a preform for producing a plastic container in a 2-stage stretch blow molding method, said preform having a preform body that extends along a central axis and that comprises: a first end a second end that lies opposite the first end, wherein the first end is closed and a neck part with a pouring opening adjoins the second end; and an inner wall that delimits an interior of the preform. Along a length of at least 30 mm of the interior, every point of the inner wall is at a distance of less than 3.5 mm from the central axis. Also disclosed are a suitable method and a device for producing such a preform.