Continuous stretch blow molding system applied to specific integral handle PET preform and container structures

Abstract

A stretch blow molding system for PET containers with PET integral handles, the containers being blown from injection molded preforms; each preform having an integral handle protruding from a joining point on a body portion of the preform; the containers being blown in a continuously rotating stretch blow molding machine of the system. In a preferred form, the preforms are advanced continuously at a substantially constant speed; the blown containers are then advanced to a filling and capping machine at the same substantially constant speed; the containers are advanced continuously through the filling and capping machine at the same substantially constant speed. Also described is a continuous stretch blow molding system that is applied to specific integral handle PET preforms and PET blown container structures stretch blow molded from the preforms, thereby obtaining variable wall thickness of the preforms and / or variable wall thickness of the containers.

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for the production of stretch blow molded PET containers from injection molded preforms.

[0002] More specifically, the present invention relates to a continuous stretch blow molding system for the production of PET containers from PET preforms in a continuous stretch blow molding process.

[0003] Additional and improved processes for the system are disclosed, including, but not limited to, controlled variation in wall thickness of the preform; controlled variation in wall thickness of the blown molded container; and, more specifically, but not limited to, controlled variation as a function of radial angle in a horizontal plane passing through selected sections of the preform; and, more specifically, but not limited to, controlled variation as a function of radial angle in a horizontal plane passing through selected sections of the blown molded container. [Background technology]

[0004] The process of stretch blow molding polymer containers from conventional injection molded preforms has long been established in the art. Typically, the preform (as injection molded) includes an elongated cylindrical body portion and a neck portion. In the stretch blow molding process, the preform enters the die (it is held by the neck portion, which retains its injection molded shape), and the body portion is first mechanically stretched in at least one direction, followed by the injection of air, forcing the polymer material into the desired shape as defined by the die cavity and also stretching the polymer material in at least one other direction (called biaxial orientation). If time elapses between the injection molding of the preforms and their entry into the blow molding process, allowing the preforms to cool to room temperature, a preheating process is applied before the preforms enter the blow mold die. In the latter case, the handle of the preform should not be affected by the stretch blow molding process, so the handle must be inserted into the handle cavity of the mold.

[0005] When the preform is rotationally asymmetric and injection molded with an integrally attached handle, as in the present case, and more specifically when the handle is in the form of a loop and is integrally attached at two points on the body of the preform, the process becomes significantly more complicated. This complexity arises primarily from the need to control the orientation of the handle and from the need to correctly preheat the body of the preform while protecting it from excessive heat absorption, as well as from the correct insertion of the preform into the stretch blow molding die. In the latter case, the handle of the preform is not affected by the stretch blow molding process, so the handle must be inserted into the mold so that it fits into the handle cavity of the mold.

[0006] Such a preform and a system for its conversion into a container with an integral handle is disclosed in WO2007101309, the entire disclosure of which is incorporated herein by reference, in which the preform enters a production machine (such as that shown diagrammatically in Figures 55 and 72 of that document) after orientation of the handle, and then that orientation is maintained through a preheat stage and into a stretch blow molding die.

[0007] However, in the system disclosed in WO2007101309, the process of production is discontinuous or "batch", i.e., the production machine advances the preforms incrementally, pausing at each index to allow pick-and-place loading of the preforms, their insertion into the supporting mandrel, and their entry into and exit from the stretch blow moulding cavity, while the preforms are stopped for each moulding cycle. The disadvantage of this incremental processing is that it is clearly less efficient than a continuous process.

[0008] The present invention relates to a machine and process for stretch blow molding preforms with integral handles in a continuous feed, and therefore non-incremental system. Due to several stages in the process, the requirements for establishing handle orientation, the preheating stage and the stretch blow molding stage, as well as removal of the finished container, require transfer of the preforms between the rotating infeed, preheating, molding, and transport elements of the system. A continuous process makes these processes and transfers significantly more complex for preforms with integral handles.

[0009] A system for handling non-rotationally symmetric preforms that require a known orientation for selective preheating and prior to loading into a stretch blow molding die was disclosed in U.S. Patent No. 8,632,333 B2. In the arrangement of this patent, orientation is established with reference to a small reference tab or notch, but the preform, which does not have a handle thereon, does not require orientation relative to a heat shield.

[0010] Also, U.S. Patent Application Publication No. 2012 / 0048683 discloses a continuously rotating blow molding system in which special precautions are taken against deformation of the preforms due to centrifugal forces due to the particular orientation of the preforms passing through the system. It is noted that such an orientation may be beneficial for asymmetric preforms (e.g., those with handles), but there is no disclosure of orientation of the preforms for entry into the handle heat shield.

[0011] U.S. Patent No. 6,779,651 specifically teaches the importance of orienting the preform with the handle prior to introduction of the preform into a stretch blow molding die, but there is no suggestion that the handle requires shielding by a heat shield, nor is there any arrangement in this patent for controlling orientation to bond the handle to a heat shield.

[0012] A series of patents and applications to Thibodeau (USD 746,142S; US Patent No. 8,524,143 B2; US Patent No. 9,499,302 B2, and WO 2015 / 112440 A1) are directed to the production of containers with integral handles that are stretch blow molded from injection molded preforms with integral handles. However, in contrast to the arrangement of the present application as described below, the handles of the containers according to Thibodeau are of a radically different shape than the handles as injection molded with the preforms, and undergo a kind of uncurling during the stretch blow molding phase.

[0013] Another continuously rotating blow molding system is disclosed in U.S. Patent No. 5,683,729, which describes mechanisms for the transfer of preforms between various stages of the system, but there is no disclosure of preforms with integral handles, and therefore no handling of special orientation of the preforms.

[0014] International patent application PCT / AU2018 / 051285 to the applicant discloses a continuous stretch blow molding system for integral handle PET containers.

[0015] To provide the process described in that application, it would be advantageous if the process described therein could be improved to require more economical use of plastic and also to allow high throughput despite distortions that may occur during reheating of the preforms and to allow efficient accommodation of downstream processes.

[0016] It would be further advantageous if the preform wall thickness could be controlled as a function of the radial angle in a horizontal plane passing through selected sections of the preform, and if the container wall thickness could be controlled as a function of the radial angle in a horizontal plane passing through selected sections of the blown container.

[0017] It is an object of the present invention to address or at least ameliorate some of the above disadvantages.

[0018] Note The term "comprising" (and grammatical variations thereof) is used herein in the inclusive sense of "having" or "including" and not in the exclusive sense of "consisting only of."

[0019] The above discussion of prior art in the background of the invention is not an admission that any of the information discussed therein is citable prior art or part of the common general knowledge of a person skilled in the art in any country.

[0020] definition Continuous preform feed: As used herein, continuous preform feed occurs when the preforms are advanced at a constant speed along a path from an entry location to an exit location. This should be distinguished from batch mode operation, where the preform feed advances and then stops while the blow molding operation takes place.

[0021] Asymmetric preform: As used herein, an asymmetric preform is a preform that is not symmetric about its longitudinal axis. The primary source of asymmetry occurs when the preform incorporates an integral handle. In certain embodiments, the preform walls are also a source of asymmetry.

[0022] Integral Handle Preform: As used herein, an integral handle preform is an asymmetric preform having a handle portion extending from a body portion of the preform, the handle being integrally molded with the body portion of the preform.

[0023] Stretch blow molding die: As used herein, a stretch blow molding die includes an openable cavity adapted to receive a preheated preform for subsequent stretch blow molding of the preheated preform within the cavity of the die. [Prior art documents] [Patent documents]

[0024] [Patent Document 1] WO2007101309 [Patent Document 2] U.S. Patent No. 8,632,333B2 [Patent Document 3] US Patent Application Publication No. 2012 / 0048683 [Patent Document 4] U.S. Patent No. 6,779,651 [Patent Document 5] USD746,142S [Patent Document 6] U.S. Patent No. 8,524,143B2 [Patent Document 7] U.S. Patent No. 9,499,302B2 [Patent Document 8] WO2015 / 112440A1 [Patent Document 9] U.S. Patent No. 5,683,729 [Patent Document 10] International patent application PCT / AU2018 / 051285 [Patent Document 11] Patent Application Publication No. 2010-274967 [Non-patent literature]

[0025] [Non-Patent Document 1] "Plastic Blow Molding Handbook", NC Lee, Springer Netherlands Publishing, May 31, 1990, pp. 101-107 Summary of the Invention [Means for solving the problem]

[0026] Thus, in one broad form of the invention, there is provided a PET container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle integrally connected to the container at at least a first connection point; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip of PET material is positioned above the container below the PET handle.

[0027] Thus, in a further broad form of the invention, there is provided a PET container having a neck portion and a body portion, wherein a PET handle is integrally connected to the body portion; the PET handle includes an elongated portion of PET material integrally connected to the container at at least a first connection point; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip of PET material is positioned on the preform and corresponding container opposite the elongated portion of PET material.

[0028] Thus, in a further broad form of the invention, there is provided a PET container having a neck portion and a body portion, wherein a PET handle is integrally connected to the body portion; the PET handle is integrally connected to the container at at least a first connection point; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip of PET material is positioned opposite the PET handle and over the preform and corresponding container.

[0029] Preferably, the handle and the narrow strip form a solid mass, thereby maintaining an integral connection between the handle and the blown moulded container.

[0030] Preferably, the integrally connected handle and narrow strip form a solid connected mass, thereby enhancing the integral connection between the handle and the blown molded container.

[0031] Thus, in a further broad form of the invention, there is provided a PET container stretch blow moulded from a preform, the preform and container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle including an elongated portion of PET material integrally connected onto the body portion of the preform and onto the container at at least a first connection point; the PET container being blown from the PET preform in a stretch blow moulding process; a region in the form of a strip of PET material being positioned on the preform and corresponding container opposite the elongated portion of the PET material handle; and the strip of material being differentiated in thickness from the thickness of the wall of the container on the side opposite the connection point.

[0032] Preferably, the handle and the narrow strip form a solid mass, thereby maintaining an integral connection between the handle and the blown molded container.

[0033] Preferably, the elongated portion of PET material comprises a stem.

[0034] Preferably, the PET handle is connected to the container at a second connection point.

[0035] Preferably, the first connection point is the upper connection point.

[0036] Preferably, the second connection point is the lower connection point.

[0037] Preferably, the preform has a neck portion and an expandable portion positioned below the neck portion.

[0038] Preferably, the area of ​​the preform body defined by the strip between the two attachment points remains substantially stable during stretching and blow molding of the container.

[0039] Preferably, both the outer surface layer and the region of the inner surface layer laterally spaced from the narrow strip undergo biaxial orientation.

[0040] Preferably, the outer surface of the narrow strip remains substantially stable, while the container walls and inner layers in the strip between the handle attachment points experience some flow and thinning along with the surrounding areas as the plasticized PET material comes under the influence of stretching and blow molding forces.

[0041] Preferably, the PET handle is formed in the same mold as the preform and at the same time as the preform is molded.

[0042] Preferably, the loading of plastics material in a region of the wall defined between the first and second locations is differentially controlled as a function of location on the periphery of the wall in this region.

[0043] Preferably, the region is designated a differential loading region.

[0044] Preferably, there is an increased loading of material in the area directly between the first and second location points, while an opposing area located diametrically opposite the differential loading area has reduced material thickness and removed therefrom, as shown in dotted outline.

[0045] Preferably, differential material loading as a function of circumferential position on the wall of the preform helps provide control of the wall thickness of the blown container.

[0046] Preferably, the stretch blow molding process is a two stage stretch blow molding process.

[0047] Preferably, the differential loading region defined between the first location and the second location remains substantially unchanged during the blow molding process.

[0048] Preferably, the differential loading area is an extension of the neck portion of the preform and a portion of the neck portion of the preform.

[0049] Preferably, the preform includes a symmetrical thickening of the wall of the preform in a lower region of the body portion extending from just below the point of connection of the lower end of the handle.

[0050] Preferably, in a second intermediate region located between the first and second connection points of the handle, the wall thickening of the preform gradually tapers from a first thickness T1 to a second, thinner thickness T2.

[0051] Preferably, the thickening is symmetrical about the longitudinal axis of the preform.

[0052] Preferably, the thickening results in a controllable increase in the thickness of the material in the blown molded container in the corresponding intermediate region and also in the sub-region directly below the first connection point at the lower end of the handle.

[0053] Preferably, the thickening results in a controllable increase in the thickness of the material in the blown molded container in the corresponding intermediate region and also in the sub-region directly below the second connection point at the lower end of the handle.

[0054] Thus, in a further broad form of the invention, there is provided an integral handle for a stretch blow molded container and an injection molded preform, the integral handle being connected at a single connection region on the body portion of the preform and at a single connection region on the body portion of the container, respectively, and the wall thickness of the body portion of the preform and the wall thickness of the body portion of the container in a region extending below the handle connection region on the body portion of the container are substantially equal to the thicknesses of the adjacent wall regions.

[0055] Preferably, the handle extends from a single area on the preform and on the container adjacent a neck portion common to both the preform and the container.

[0056] Preferably, the handle includes an upper arcuate portion extending from the single connection region; the arcuate upper portion transitions into a substantially straight downwardly projecting portion.

[0057] Preferably, the handle includes a central web that lies in a central plane passing through a centerline of the body portion of the preform and a plane that bisects the body portion of the container.

[0058] Preferably, the central web is bounded by an edge; the edge extends continuously around the periphery of the web from an upper joining point to a lower joining point on both the preform body portion and the container body.

[0059] Preferably, ribs perpendicular to the webs extend along the edges; the ribs project outwardly and symmetrically from both sides of the plane; and the ribs and central web form an I-beam-like cross section.

[0060] Preferably, the upper and lower connecting sections of the rib blend with the surfaces of both the preform body portion and the body of the container.

[0061] Preferably, the inwardly facing sections of both the webs and ribs are provided with one or more scalloped formations; the scalloped formations aid in gripping the handle in use.

[0062] Preferably, a thumb support is provided projecting from the upper portion of the rib.

[0063] Thus, in a further broad form of the invention, there is provided a method for reducing the volume of PET polymer in a container stretch blow molded from an injection molded preform with an integral handle, the handle being formed as a loop extending between first and second connection points on a body portion of the preform; the method comprising: a. modifying the integral handle of the preform from an integral handle formed as a loop to a single connect handle extending from a single connection area on a body portion of the preform; b. reducing the wall thickness of the body portion of the preform in a region below the connection region of the single connect handle from the reinforced thickened wall to a thickness equal to the wall thickness of the adjacent region of the preform; A method is provided, comprising:

[0064] Preferably, the handle extends from a single connection region on the preform and on the container adjacent a neck portion common to both the preform and the container.

[0065] Preferably, the handle includes an upper arcuate portion extending from a single region; the arcuate upper portion transitions into a substantially straight downwardly projecting portion.

[0066] Preferably, the handle includes a central web that lies in a plane passing through a centerline of the body portion of the preform and a plane that bisects the body portion of the container.

[0067] Preferably, the central web is bounded by an edge; the edge extends continuously around the periphery of the web from an upper joining point to a lower joining point on both the preform body portion and the container body.

[0068] Preferably, ribs perpendicular to the webs extend along the edges; the ribs project outwardly and symmetrically from both sides of the web; and the ribs and central web form an I-beam-like cross-section.

[0069] Thus, in a further broad form of the invention, there is provided a single connect handle for a stretch blow molded container, the container being stretch blow molded from an injection molded preform; the preform including an integral handle connected at a single connection region of the preform; the handle extending outwardly from and generally parallel to a section of a body portion of the preform, the wall thickness of the preform at the section of the body portion being equal to the wall thickness of an adjacent region of the preform.

[0070] Thus, in a further broad form of the invention, there is provided an injection molded preform with an integral handle for stretch blow molding a container with an integral handle, the preform having a cylindrical body portion extending from below a neck of the preform and a curved closure at a base of the body portion; the walls of the cylindrical body portion of the preform are of constant thickness.

[0071] Preferably, the integral handle is connected to the preform at a single connection region; the handle extends outwardly and generally parallel to the section of the body portion of the preform.

[0072] Thus, in a further broad form of the invention, there is provided a PET container stretch blow molded from a preform, the preform and container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle including an elongated portion of PET material integrally connected at least at a first connection point onto the body portion of the preform and onto the container; and the wall thickness of the preform is controlled such that the wall thickness 1421B in a region of the container 1420B located below the handle 1426 and on the side of the container nearest the handle 1426 can be differentiated from the wall thickness 1441B in a region 1440B located on the opposite side of the container 1428 from region 1420B, and at a corresponding location on the blown container 1428.

[0073] Preferably, the handle and the narrow strip form a substantially planar area, thereby maintaining an integral connection between the handle and the blown moulded container.

[0074] Preferably, the elongated portion of PET material comprises a stem.

[0075] Preferably, the PET handle is connected to the container at a second connection point.

[0076] Preferably, the first connection point is the upper connection point.

[0077] Preferably, the second connection point is the lower connection point.

[0078] Preferably, the preform has an expandable portion located below the neck portion.

[0079] Preferably, the area of ​​the preform body defined by the strip between the two attachment points remains substantially stable during stretching and blow molding of the container.

[0080] Preferably, both the outer surface layer and the area of ​​the inner surface layer laterally spaced from the narrow strip undergo biaxial orientation.

[0081] Preferably, the outer surface of the narrow strip remains substantially stable, while the container walls and inner layer in the strip between the handle attachment points undergo some flow and thinning along with the surrounding areas as the PET material comes under the influence of stretching and blow molding forces.

[0082] Preferably, the PET handle is formed in the same mold as the preform and at the same time as the preform is molded.

[0083] Preferably, the loading of plastic material in a region of the wall defined between the first location and the second location is differentially controlled as a function of location on the periphery of the wall in this region; that region is designated the differential loading region.

[0084] Preferably, there is an increased loading of material in the area directly between the first and second location points, while an opposing area located diametrically opposite the differential loading area has a reduced material thickness.

[0085] Preferably, differential material loading as a function of circumferential position on the wall of the preform helps provide control of the wall thickness of the blown container.

[0086] Preferably, the stretch blow molding process is a two stage stretch blow molding process.

[0087] Preferably, the differential loading region defined between the first location and the second location remains substantially unchanged during the blow molding process.

[0088] Preferably, the differential loading area is an extension of the neck portion of the preform and a portion of the neck portion of the preform.

[0089] Preferably, the preform includes a symmetrical thickening of the wall of the preform in a lower region of the body portion extending from just below the point of connection of the lower end of the handle.

[0090] Preferably, in a second intermediate region located between the first and second connection points of the handle, the wall thickening of the preform gradually tapers from a first thickness to a second, thinner thickness.

[0091] Preferably, the thickening is symmetrical about the longitudinal axis of the preform.

[0092] Preferably, the thickening results in a controllable increase in the thickness of the material in the blown molded container in the intermediate region and in the sub-region directly below the second connection point at the lower end of the handle.

[0093] Thus, in a further broad form of the invention, there is provided a method of controlling a preform for stretch blow molding a container having an integrally formed handle, the preform including a body portion and an integrally formed handle; the preform is transferred from a preform supply to a blow molding die for blowing the container; the method includes: - passing the preform through a preform handle orienting device; - transferring the preforms to a preform transport system; - maintaining the orientation of the preform handle imposed by the preform handle orienting device during transfer to the preform transport system and during transfer to the blow moulding die; - rotating the preform while transporting it along a transport system past the array of preform heating elements while shielding the integrally formed handle from excessive exposure to the heating elements; - transferring the preform from the transport system to a blow molding die; Including, The handle includes an orientable plastic material extending from at least an upper connection region on a body portion of the preform, the method comprising: A method is provided in which the handle includes a curved reinforcing element at a lower end of the handle; and the orientable plastic material is bifurcated to form an enclosed generally triangular element.

[0094] Preferably, the handle extends from an upper connection region to a lower connection region on the body portion of the preform.

[0095] Preferably, the curved reinforcing element abuts the body portion of the preform and the body of the blown container.

[0096] Preferably, the curved reinforcing element generally matches, in width and cross-section, the width and cross-section of the handle.

[0097] Preferably, the handle has a gradually diverging cross-section approaching the upper connection region; the cross-section reaches and maintains a maximum width adjacent the upper connection region cross-section of the handle.

[0098] Preferably, the cross-section extends from the opposed outer edges towards the centreline; the cross-section gradually increases in thickness from the outer edges to a maximum thickness at the centreline.

[0099] Preferably, the handle includes a straight section that angles downwardly from the lower connection region and an arcuate section that extends from the end of the straight section to the upper connection region.

[0100] Preferably, integrally molded first, second and third reinforcing elements are provided in each of the upper and lower connection regions and at the junctions between the straight and arcuate sections, respectively.

[0101] Preferably, the first reinforcing element in the upper connection region includes a first curved element, which in width and cross-section matches the width and cross-section of the handle adjacent the upper connection region; the first curved element extends from the first separate connection region below the upper connection region and merges with the handle adjacent the first end of its widest point.

[0102] Preferably, the second reinforcing element in the lower connection region comprises a straight element, which in width and cross-section matches the width and cross-section of the straight section of the handle; the straight element extends from the second separate connection region above the lower connection region and merges with the straight section of the handle adjacent the lower connection region.

[0103] Preferably, the third reinforcing element at the junction of the straight and arcuate sections of the handle includes a further curved element, the further curved element matching in width and cross-section with the width and cross-section of the handle adjacent the junction of the straight and arcuate sections of the handle; and each outer end of the curved element blends with the straight and arcuate sections of the handle.

[0104] Preferably, each reinforcing element includes a web of orientable plastic material within the boundaries formed between the body of the preform and the first and second reinforcing elements, and between the third reinforcing element and the straight and arcuate sections, respectively; each web of orientable plastic material is aligned with the centerline and extends equally in both directions from the centerline.

[0105] Thus, in a further broad form of the invention, there is provided a method of reducing strain on the supporting fingers of a hand lifting a blow-molded container, the container being provided with an integral handle; the method comprising: - stretch blow molding a container from a preform including an orientable plastic material forming a handle; the orientable plastic material extending from at least an upper connection region; A method is provided in which: the handle includes a curved reinforcing element at a lower end of the handle; and the orientable plastic material is bifurcated to form an enclosed generally triangular element.

[0106] Preferably, the handle extends from an upper connection region to a lower connection region on the body portion of the preform.

[0107] Preferably, the curved reinforcing element abuts the body portion of the preform and the body of the blown container.

[0108] Preferably, the curved reinforcing element generally matches, in width and cross-section, the width and cross-section of the handle.

[0109] Preferably, the reinforcing element is adjacent to the upper connection region; the reinforcing element includes a first curved element, the first curved element generally conforming in width and cross-section to the width and cross-section of the handle adjacent to the upper connection region; the first curved element extends from the first separate connection region below the upper connection region and merges with the handle adjacent the first end of its widest point.

[0110] Thus, in a further broad form of the invention, there is provided a handle for a stretch blow molded container, the container blown from a preform including a handle extending from at least an upper connection region; the handle including a curved reinforcing element at a lower end of the handle; the curved reinforcing element generally conforming in width and cross-section to the width and cross-section of the handle; and the orientable plastic material is bifurcated to form an enclosed generally triangular element.

[0111] Preferably, the handle extends from an upper connection region to a lower connection region on the body portion of the preform.

[0112] Preferably, the curved reinforcing element abuts the body portion of the preform and the body of the blown container.

[0113] Preferably, the curved reinforcing element generally matches, in width and cross-section, the width and cross-section of the handle.

[0114] Preferably, the handle further includes a straight lower section and an arcuate section extending from an end of the straight lower section to the upper connection region; the handle has a gradually widening cross-section approaching the upper connection region; and the cross-section reaches and maintains a maximum width adjacent the upper connection region.

[0115] Thus, in a further broad form of the invention there is provided a blown moulded container formed according to any of the above methods.

[0116] Thus, in a further broad form of the invention there is provided a blow moulded container incorporating a handle as described above.

[0117] Thus, in a further broad form of the invention, there is provided a preform having a handle, the preform being formed in a first production step of a stretch blow molded container; a container blow molded from the preform including a handle extending from at least an upper connection region; the handle including a straight lower section and including a curved reinforcing element at a lower end of the handle; and the orientable plastic material being bifurcated to form an enclosed generally triangular element.

[0118] Preferably, the handle extends from an upper connection region to a lower connection region on the body portion of the preform.

[0119] Preferably, the curved reinforcing element abuts the body portion of the preform and the body of the blown container.

[0120] Preferably, the curved reinforcing element generally matches, in width and cross-section, the width and cross-section of the handle.

[0121] In a preferred form, all of the above cavities, systems, preforms, processes, containers, handles, features, and methods are realized in a continuously rotating, asymmetric preform feed, stretch blow molding machine specialized for stretch blow molding containers from asymmetric injection molded preforms, the asymmetric preforms including integral handles extending from a juncture point on a body portion of the preform; and the body portion of the preform and the integral handle are constructed from the same material.

[0122] Additional features of the machine in a preferred form are outlined immediately below.

[0123] Thus, in one broad form of a continuously rotating, asymmetric preform feed stretch blow molding machine, there is provided a continuously rotating, asymmetric preform feed stretch blow molding machine specialized for stretch blow molding containers from asymmetric injection molded preforms, the asymmetric preforms including an integral handle extending from a joint point on a body portion of the preform; and the body portion of the preform and the integral handle are constructed from the same material.

[0124] In a further broad aspect of the continuously rotating asymmetric preform feed stretch blow molding machine, there is provided a method of controlling paths of grippers of pick and place devices of a rotary transfer system operating in the continuous asymmetric preform feed stretch blow molding machine; the gripper paths follow trajectories of each of the asymmetric preforms as the preforms are transferred by the rotary transfer system from a preform pick-off location, inserted into and extracted from a preform support mandrel of a preheat stage, and inserted into and extracted from a rotating stretch blow molding die as stretch blow molded containers; the asymmetric preforms include a body portion and an integral handle extending from the body portion; the method includes the steps of rotatably mounting each of the pick and place devices on a rotating arm of a respective rotary transfer system.

[0125] In a further broad form of the continuous rotating asymmetric preform feed stretch blow molding machine, there is provided a method of transferring an asymmetric preform between stages of a continuous asymmetric preform feed rotating stretch blow molding machine, where the asymmetric preform is converted into a stretch blow molded container by stretching and blowing the asymmetric preform in a cavity of a stretch blow molding die; the method including orienting the asymmetric preform such that an integral handle of the preform has a known orientation when it arrives at a pick-off location in the machine.

[0126] In a further broad form of the continuously rotating asymmetric preform feed stretch blow molding machine, there is provided a method of maneuvering an asymmetric injection molded preform into a stretch blow molding die of a continuous preform feed stretch blow molding machine, the method including the step of extracting a preform from a preform preheat stage by a pick and place device of a continuously rotating transport system such that an integral handle of the preform has a predetermined orientation.

[0127] In a further broad form of the continuously rotating asymmetric preform feed stretch blow molding machine, there is provided a method of controllably heating a preform to a die entry temperature, the preform having a neck portion extending from a body portion; the preform further having a handle extending partially radially; the method comprising the steps of controllably transporting the integral handle PET preform onto a continuously moving conveyor; and securing the preform to the conveyor by its neck portion, whereby the preform is transported by the conveyor at a substantially constant speed along a preheating path from a preform entry location to a preform exit location.

[0128] Preferably, at least a portion of the preform is controllably heated to the die entry temperature by the time it reaches the preform exit location.

[0129] Preferably, controllable heater arrays distributed along the path are positioned to direct heat to selected portions of the preform.

[0130] Preferably, the preform is controllably transferred from the preform exit location into a die for stretch blow molding of the preform, thereby forming a blown container.

[0131] In a further broad form of the continuously rotating asymmetric preform feed stretch blow molding machine, there is provided a method of orienting an asymmetric preform for entry into a stage of a stretch blow molding machine, the asymmetric preform including an integral handle extending from a first attachment point below a neck portion of the preform to a second attachment point above a body portion of the preform; the method comprising the steps of providing the preform while supported by the neck portion of the preform to slide along an upper rail of an angled rail and down the angled rail towards an orientation mechanism.

[0132] In a further broad form of the continuously rotating, asymmetric preform feed stretch blow molding machine, there is provided a continuously rotating, asymmetric preform feed stretch blow molding machine in which an injection molded preform with an integral handle is transferred from a first transfer system to a preheat stage; and transfer of the preform from the gripper of the first transfer system to a preform support mandrel is accomplished in one fluid motion as the vertical axis of the preform is brought into alignment with the vertical axis of the preform support mandrel and the handle of the preform is slid into a heat shield provided over the mandrel.

[0133] Thus, in a further broad form of the continuously rotating asymmetric preform feed stretch blow molding machine, there is provided a continuous asymmetric preform feed stretch blow molding machine specialized for stretch blow molding a container from an asymmetric injection molded preform, the asymmetric preform including an integral handle extending from a first attachment point to a second attachment point on a body portion of the preform; the body portion of the preform and the integral handle are constructed from the same material; and the machine includes a preform orientation system for orienting the handle of the preform in a known orientation upon arrival at a pick-off location.

[0134] Preferably, the preform undergoes continuous motion from an initial preform pick-off point, through stretch blow molding into a container, and through ejection from the machine as a stretch blow molded container.

[0135] Preferably, the integral handle retains the shape of the handle when injection molded through all stages of the stretch blow molding machine to form a handle on the stretch blow molded container.

[0136] Preferably, the stages of the stretch blow molding machine include a handle-orienting stage; every preform arriving at a pick-off point has an integral handle oriented in a predetermined direction relative to the movement of the preform approaching the pick-off location.

[0137] Preferably, the stage of the stretch blow molding machine includes a continuously rotating first transfer system which transfers preforms from a continuously rotating preform feeder wheel at a preform pick-off location to a preheat location at a continuously rotating preheat stage.

[0138] Preferably, the first pick and place device of the first transfer system includes a preform gripping gripper; the reciprocating rotation and linear displacement of the gripper is induced by a combination of a rotating carrier and two cam trajectories of the pick and place device.

[0139] Thus, in a further broad form of the invention, there is provided a method for controllably heating a preform to a die entry temperature, the preform having a neck portion extending from a body portion; the preform further having an integrally injection molded radially extending handle portion; the method comprising: - controllably transferring the integral handle PET preform onto a continuously moving conveyor while maintaining a known orientation of the handle portion; - fixing the preforms by their neck portions to a conveyor, whereby the preforms are continuously transported by the conveyor from a preform entry location to a preform exit location; Includes; - at least a portion of the preform is controllably heated to a die entry temperature by the time it reaches the preform exit location; - controllable heater arrays distributed along the path conveyor are positioned to direct heat to selected portions of the preforms; - the preform is controllably transferred from the preform exit location into a die for stretch blow molding of the preform, thereby forming a blown molded container; A method is provided in which the preform includes an open neck portion and a hollow body extending from the neck portion; at least a portion of a wall of the hollow body varies in thickness, and a cross-section of at least a portion of an inner surface of the hollow body is oval in cross-section.

[0140] Preferably, the handle portion is solid and has a first end and a second end; the first end is integrally connected to the preform at a first, upper location; and the second end is integrally connected to the preform at a second, lower location.

[0141] Preferably, the first upper location is located above the body portion.

[0142] Preferably, the first upper location is located above the neck portion.

[0143] Preferably, the second lower location is located above the body portion.

[0144] Preferably, the elements are arranged in modules; the modules are arranged around a continuously rotating preform conveyor; and the elements are controlled as a group based on height, with the topmost elements of the module being controlled together to a predetermined temperature, while the next lower elements in height are also controlled together to a predetermined temperature, down to the elements at the lowest level.

[0145] Preferably, the processor controls the speed of rotation of the motor to control the continuous speed of advancement of the preform.

[0146] Preferably, the temperature sensor provides environmental temperature sensing that is utilized by the processor to modulate the degree of heating of all elements by a difference factor delta (Δ).

[0147] Preferably, the step of controllably transporting the integral handle PET preforms onto a continuously moving conveyor includes the step of orienting the handles of the preforms in a known orientation when they arrive at a pick-off location.

[0148] Preferably, the preform includes an open neck portion and a hollow body portion extending from the neck portion; the preform further includes an integrally injection molded handle; and at least a portion of the wall of the hollow body portion varies in thickness.

[0149] Preferably, at least a portion of the inner surface of the hollow body is non-concentric with the outer surface of the hollow body.

[0150] Preferably, the outer surface of the hollow body is defined by a diameter centered on the central longitudinal axis of the preform to form a substantially cylindrically shaped body.

[0151] Preferably, the cross section of at least a portion of the inner surface of the hollow body is oval in cross section.

[0152] In a further broad form of the invention, there is provided a method of optimizing wall thickness in a stretch blow molded container, the method comprising: - injection molding hollow preforms, at least a lower portion of each preform having an internal cross section that is non-concentric with an outer surface of the lower portion; - bringing the preform to a temperature appropriate for stretch blow molding; - inserting a preform into a cavity of a stretch blow molding machine; - mechanically stretching the preform and injecting air to form a container; A method is provided, comprising:

[0153] In a further broad form of the invention, there is provided a mandrel forming an interior surface of an injection molded hollow preform, the mandrel including at least one portion having a non-concentric cross-section that defines by a diameter an outer surface of the preform.

[0154] In a further broad form of the invention there is provided a method for urging the dispensing of polymeric material from a wall of at least one portion of a preform as defined above to a selected sidewall of a container stretch blow moulded from the preform, the method comprising: - disposing a mandrel defining an inner surface of the preform having at least one portion cross-section that is non-concentric with a corresponding outer surface of the preform as defined by a cavity of the preform injection molding die; - placing the mandrel in the injection molding die such that a major axis of a cross section of at least one portion of the mandrel is aligned with a central vertical plane of the cavity; - injection molding the preform; - introducing a preform into a cavity of a stretch blow molding machine such that a central vertical plane of the preform is aligned with a central vertical plane of a blown container of generally rectangular cross section; Including, A method is provided wherein a central vertical plane of the container is parallel to opposing long sides of the container.

[0155] Preferably, the centre of the oval shaped cross-section is centred on the longitudinal axis of the preform.

[0156] Preferably, the centre of the oval shaped cross-section is offset from the longitudinal axis of the preform.

[0157] Preferably, the centre of the circular cross section of the portion of the hollow body is offset from the longitudinal axis of the hollow body.

[0158] Embodiments of the present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0159] [Figure 1] FIG. 1 is a side view of a preform with an integral handle for stretch blow molding a container by a continuous blow molding machine. [Diagram 2] FIG. 2 is a side view of a container with an integral handle stretch blow molded from the preform of FIG. 1. [Diagram 3] FIG. 3 is a plan view of a stretch blow molding machine for producing the container of FIG. 2. [Figure 4] FIG. 4 is a side view of the preform orientation and loading section of the machine of FIG. [Figure 4A] FIG. 4 is a plan view of the preform orientation and loading section of the machine of FIG. 3. [Figure 4B] FIG. 4 is a plan view of a further preferred embodiment of a preform orientation arrangement for the machine of FIG. [Figure 4C]FIG. 4C is a side elevational view of the alignment structure of FIG. 4B. [Figure 4D] FIG. 4D is a perspective view from below of the orientation structure of FIGS. 4B and 4C. [Diagram 5] 5 is a plan view of the loading end of the preform orienting and loading section of FIG. 4 and of a first preform transport system. FIG. [Figure 6] FIG. 6 is a side view of the first preform transfer system of FIG. 5. [Figure 7] FIG. 7 is a plan view of a portion of the preform transport system of FIGS. 5 and 6 and the preform loading and unloading area of ​​the preform preheating stage of the machine. [Figure 8] FIG. 2 is a perspective view of the preform of FIG. 1 inserted into a mandrel with a heat shield for transport through a preform preheat stage of a machine. [Figure 9] FIG. 8 is an enlarged plan view of a section of the machine showing a portion of the preform loading and unloading area of ​​FIG. 7, a second transfer system, and a portion of the stretch blow molding die assembly of the machine. [Figure 10] FIG. 3 is a front view of one half of a stretch blow molding die for producing the container shown in FIG. 2. [Figure 11] FIG. 4 is a plan view of a portion of the machine of FIG. 3 showing the area of ​​transfer of blown containers from the stretch blow molding die to a container receiving bin. [Figure 12] FIG. 1 is a schematic block diagram of control components associated with controls for heating and transport of preforms usable with any of the embodiments described above. [Figure 13] FIG. 1 is a side view of a typical injection molded preform for stretch blow molding of polymeric containers according to the prior art. [Figure 13A] FIG. 2 is a cross-sectional side view of a preform according to a preferred embodiment of the present invention, with a central vertical plane passing through the central vertical axis of the preform lying in the plane of the paper. [Figure 14]FIG. 13B is a side view of a mandrel for injection molding the preform of FIG. 13A, with a central vertical plane passing through the central vertical axis of the mandrel lying in the plane of the paper. [Figure 15] FIG. 15 is a cross-sectional view along the vertical center axis of the mandrel of FIG. 14 taken at the level AA. [Figure 16] FIG. 4 is a cross-sectional view along the vertical center axis of the mandrel of FIG. 3 taken at level BB. [Figure 17] FIG. 3 is a side view of a container stretch blow molded from the preform of FIG. 2. [Figure 18] FIG. 18 is an end view of the container of FIG. 17. [Figure 19] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 19A] 20 is a selected cross-sectional view of the preform of FIG. 19. [Figure 19B] 20 is a selected cross-sectional view of the preform of FIG. 19. [Figure 20] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 20A] 21 is a selected cross-sectional view of the preform of FIG. 20. [Figure 20B] 21 is a selected cross-sectional view of the preform of FIG. 20. [Figure 21] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 21A] 22 is a selected cross-sectional view of the preform of FIG. 21. [Figure 21B] 22 is a selected cross-sectional view of the preform of FIG. 21. [Figure 22] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 22A] 23 is a selected cross-sectional view of the preform of FIG. 22. [Figure 22B] 23 is a selected cross-sectional view of the preform of FIG. 22. [Figure 23]FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 23A] FIG. 24 is a selected cross-sectional view of the preform of FIG. 23. [Figure 23B] FIG. 24 is a selected cross-sectional view of the preform of FIG. 23. [Figure 24] FIG. 24 is a schematic diagram of an injection molding process for producing the preforms of FIGS. 13A and 19, 20 to 23. [Diagram 25] FIG. 14 shows a container with an integral handle as blown from the preform of FIG. 13. [Figure 26] FIG. 1 illustrates a reduced PET volume preform according to a preferred embodiment of the present invention. [Figure 27] FIG. 27 is a cross-sectional view of the body portion of the preform of FIG. 26 showing variations in wall thickness. [Figure 28] FIG. 28 is a side view of a container stretch blow molded from the preform of FIGS. 26 and 27. [Figure 29] FIG. 13 is a further side view of a stretch blow molded preform with an integrally formed handle in a machine of the present invention. [Diagram 30] FIG. 2 is a schematic cross-sectional side view of an injection molding press and injection molding die for molding preforms for use in the continuous rotary stretch blow molding machine of the present invention, with the die open prior to the injection molding cycle. [Diagram 31] FIG. 31 is a front view of the face of the moving die section of the injection molding die of FIG. 30 at the end of an injection molding cycle (with the heated stationary die section removed). [Diagram 32] FIG. 13 is a further view of a portion of an injection molding press showing extraction of the molded preform by a vacuum element inserted into the open die by a robot. [Diagram 33] FIG. 2 is a side view of a preferred embodiment of a preform and integrally attached handle in accordance with the present invention. [Diagram 34] FIG. 34 is an end view of the preform of FIG. 33. [Diagram 35] FIG. 35 is a top view of the preform and handle of FIGS. 33 and 34. [Diagram 36] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 36A] FIG. 37 is a selected cross-sectional view of the preform of FIG. 36. [Figure 36B] FIG. 37 is a selected cross-sectional view of the preform of FIG. 36. [Figure 37] FIG. 2 is a cross-sectional side view of a further preferred embodiment of a preform according to the present invention. [Figure 37A] FIG. 38 is a selected cross-sectional view of the preform of FIG. 37. [Figure 37B] FIG. 38 is a selected cross-sectional view of the preform of FIG. 37. [Figure 38] FIG. 1 is a perspective view of a container according to an embodiment of the present invention having a variable wall thickness as a function of radial angle in a selected horizontal plane. [Figure 39] FIG. 39 is a side view of the vessel of FIG. 38, defining a selected horizontal plane. [Diagram 40] FIG. 39 is a top view of the vessel of FIG. 38 defining the angular reference and plotting the wall thickness through selected planes XX, YY, ZZ. [Diagram 41] FIG. 2 is a schematic plan view of a container redirecting device positioned intermediate a stretch blow molding machine and a filling and capping machine. [Diagram 42] FIG. 13 is a side view of a preform with integral handles attached in two locations as configured and manufactured in accordance with a further preferred embodiment. [Diagram 43] FIG. 43 is a side view of a container stretch blow molded from the preform of FIG. 42. [Diagram 44] FIG. 2 is a side view of a preform with an integral handle attached at a single point according to the present invention. [Diagram 45] FIG. 45 is a side view of a container with a single connect integral handle stretch blow molded from the preform of FIG. [Diagram 46] 13A-13C are side cross-sectional views of further examples of preforms with handles attached at a single point, with alternative variable wall profiles; [Figure 47] 13A-13C are side cross-sectional views of further examples of preforms with handles attached at a single point, with alternative variable wall profiles; [Figure 48] FIG. 1 is a side view of a preform for stretch blow molding a container with an integral doubly connected handle. [Figure 49] FIG. 2 is a side view of the preform of FIG. 1 distorted after passing through a preconditioning stage in a stretch blow molding machine. [Figure 50] FIG. 50 is a front view of one half of a stretch blow molding die adapted to correct distortion of the preform of FIG. 49. [Figure 51] FIG. 51 is a side view of a container with an integral doubly connected handle stretch blow molded from the preform of FIG. 49 in the die of FIG. 50. [Figure 52] FIG. 1 is a side view of a preform for stretch blow molding a container with an integral single connected handle that is distorted after preheating. [Diagram 53] FIG. 53 is a side view of a container with an integral single connected handle stretch blow molded from the preform of FIG. 6 in the die of FIG. 52. [Figure 54] FIG. 54 is a further side view of the container of FIG. 53. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0160] Below is a detailed description of a continuous stretch blow molding system applied to a particular integral handle PET preform and a PET blow molded container structure stretch blow molded from the preform.

[0161] The continuous stretch blow molding system will be described first, followed by specific applications. In its simplest form, the stretch blow molding system can be a single stage molding system. In an alternative form, it can be a 1.5 stage system. In a further form, it can be a two stage system.

[0162] The system, as will be described, uses a continuous process to stretch blow integral handle PET containers from integral handle PET preforms.

[0163] The system stretch blows an integrally handled PET container from an asymmetric injection molded preform; the asymmetric preform includes an integral handle extending from at least one joining point on a body portion of the preform; and the body portion of the preform and the integral handle are constructed from the same PET material.

[0164] In a first preferred form, a feature of the continuous machine 10 of the present invention (a preferred configuration of which is shown in FIG. 3) is that the movement of an asymmetric injection molded preform 12, as shown in FIG. 1, through the machine is continuous from its initial intake to its emergence as a stretch blow molded container 14 (as shown in FIG. 2). As shown in FIG. 1, the previously injection molded polymer preform includes an elongated cylindrically shaped body portion 16 and a neck portion 18. An integral handle 20 extends from a first attachment point 22 just below the neck portion 18 to a second attachment point 24 above the body portion 16 of the preform.

[0165] 3, the continuous, non-incremental process of the machine 10 includes the transfer of the preform from the loading or pick-off location 26 to a preheat stage 28, transfer through the preheat stage, and transfer to the stretch blow molding die 30, followed by removal of the blown container 14 from the die and removal from the machine. These stages will now be described in detail.

[0166] Preform Entry and Handle Orientation - First Preferred Embodiment As shown in the preferred layout of the machine 10 in Figure 3, and with reference also to Figures 4 and 5, previously injection molded preforms 12 (as shown in Figure 1) are fed, for example, from a hopper (not shown, but well understood in the art) and slide under gravity down an inclined rail 32 while supported by their necks 18. The inclined rails 32 include a pair of upper rails 32a and a pair of lower rails 32b between which the preforms are suspended by their necks 18 and which constrain the preforms' handles 20 in approximate alignment with the rails' long axes. However, for reasons that will become apparent, it is essential that the orientation of the preforms' integral handles 20 be precisely controlled as they pass through the machine stages.

[0167] The preforms 12 with their handles roughly oriented pass, one by one, through an escapement 34 and are picked up by a continuously rotating feeder wheel 36 which carries the preform between it and a short rail 40 such that friction between the body 16 of the preform and the rail 40 induces rotation of the preform and its handle. The rotating handles collide with stops 40a below the rail 40, orienting their respective handles backwards relative to the direction of travel, until they reach the pick-off position 26.

[0168] At the moment the preform arrives at the pick-off location 26, a pair of opposing actuators (not shown) positioned below the pick-off location 26 simultaneously close for a short period onto the preform handle 20 and then release it, fixing its orientation relative to the gripper 58, which also at that moment engages the neck portion 18 of the preform.

[0169] Preform Entry and Handle Orientation - Second Preferred Embodiment In this second preferred embodiment, now referring to Figure 4A, the injection molded preforms 12 are again fed onto the inclined rails 32a where they slide under gravity supported by flanges at the necks 18. Again, as described with respect to the first preferred embodiment above, the handles are loosely constrained between the lower rails 32b, and the handles are in either a "leading" or "trailing" position, with "leading" pointing in the direction of the preform's travel as it progresses down the incline and "trailing" pointing backwards.

[0170] In this second preferred embodiment, an orientation mechanism 34A is positioned at a point along the rail 32 close to the lower end of the rail. As can be seen in Figure 4A, the mechanism includes two counter-rotating drive wheels 33 and 35, which are located on either side of the rail 32, at a level coinciding with the lowest portion of the body of the preform, and below the lowest point of the lower rail 32b and handle. The axis of the wheels is perpendicular to the slope of the inclined rail. Note that only the lower rail 32b is shown in Figure 4A.

[0171] The drive wheels 33 and 35 are separated by a gap 37 which is somewhat narrower than the diameter of the preform body 16. Each of the wheels 33 and 35 is provided with one or two tires 39 of a sufficiently soft polymeric material to allow the preform body 16 to pass through the gap while still providing some grip on the body.

[0172] As shown in Figure 4A, drive wheel 33 rotates in a counterclockwise direction while drive wheel 35 rotates in a clockwise direction. The combination of these two rotations has the effect of drawing the preform through gap 37. However, the two drive wheels do not rotate at the same rate, with the preferred arrangement shown in Figure 4A resulting in drive wheel 35 rotating at a significantly lower rpm than the rpm of guide wheel 33. The preferred ratio of rotation of drive wheel 33 to drive wheel 35 is on the order of 2:1.

[0173] The effect of this difference in the rates of rotation of the two drive wheels is that the drive wheel 35 exerts a significantly greater grip on the body portion 16 of the preform, such that as the preform passes through the gap 37 between the two drive wheels, the drive wheel 35 acts to rotate the preform in a counterclockwise direction. By this means, the handle 20 of the preform, which is in the leading position as the preform enters the gap 37, is caused to rotate until it contacts the right hand lower rail 32b (as viewed from above in Figure 4A). To allow this rotation of the handle, a gap 40 is provided in the left hand lower rail.

[0174] It will be appreciated that the counterclockwise rotation induced by drive wheel 35 has no effect on those preforms entering the gap with their trailing handles, other than driving the trailing handles into contact with the right hand side lower rail. Thus, all preforms downstream of orienting mechanism 34A approach the escapement 34 in the preferred orientation with their handles in the trailing position.

[0175] The escapement 34, as described above, controls the feeding of the handled oriented preform to the feeder wheel 36, and maintains the handle trailing orientation as induced by mechanism 34A. With respect to the first arrangement above, at the moment the preform arrives at the pick-off location 26, a pair of opposing actuators (not shown) positioned below the pick-off location 26 simultaneously close for a short period on the preform handle 20 and then release it, fixing its orientation against the gripper 58, which also at that moment engages the neck portion 18 of the preform.

[0176] While the above description is specific to rotation of the preform in a counterclockwise direction by a clockwise rotating drive wheel, it will be understood that orientation according to the principles of the mechanism can equally be achieved by reversing the differential rate of rotation of the two drive wheels and by providing a gap in the lower guide rail on the opposite side to that shown in Figure 4A. In this alternative arrangement, the counterclockwise rotating drive wheel induces a clockwise rotation in the body of the preform passing between the wheels, rotating it until the leading oriented handle contacts the left hand side lower rail (as viewed from above in Figure 4A), and then a gap is provided in the right hand side lower rail to allow the handle to rotate.

[0177] Precise orientation of the handle throughout the machine stages is important for the pre-heating process, where the orientation must match the alignment of the heat shield, and also for correct placement of the preform and handle into the stretch blow molding die.

[0178] Preform Entry and Handle Orientation - Third Preferred Embodiment 4B-4D, in this further preferred arrangement of the handle orienting mechanism 34b, injection molded preforms 12 emerge one at a time from a bulk supply, e.g., via a conveyor (not shown), and are centrally disposed over a pair of counter-rotating, downwardly inclined rollers 11 and 13. The rollers 11 and 13 are spaced apart to allow the body portion 16 and handle 20 of each preform to fall through the gap between the rollers 11 and 13, but retain the wider diameter of the protruding collar below the neck portion 18 of the preform. The rollers 11 and 13 are mounted above a pair of spaced apart guide rails 15 and 17 (as best seen in FIG. 4D), which are spaced apart similarly to the gap between the rollers. As the preform body and handle drop through the gap between the rollers and through the gap between guide rails 15 and 17, the handle 20 is constrained in approximate alignment between these rails, but at this stage the handle can be "leading" or "trailing" relative to the downward movement shown in Figures 4C and 4D. Because it is a requirement imposed by the blow molding machine design, described below, that the preform handles at the entry of the preform into the feeder wheel 36 must be in a trailing position, their leading must be reversed.

[0179] At the downward ends of the rollers, the preforms drop to the level of the main support rails 19 and 21 such that the preforms are now held between these main support rails by their collars. A combination of gravity and pressure from the succeeding preforms presses each preform against the upward outer ends of side-by-side counter-rotating auger screws 23 and 25, located on either side of a central vertical plane between the support rails. The flutes 27 of the auger screws are sized to capture the necks 18 of the preforms between them. The pitch of the auger screws is such that they separate the preforms as they are driven downwardly by the rotation of the screws.

[0180] Generally coextensive with the length of one of the auger screws (auger screw 25 in the arrangement shown in the drawings), main support rail 21 is provided on its underside (as best seen in the enlarged inset of FIG. 4D ) with a friction strip 29. This friction strip 29 protrudes slightly into the gap between main support rail 19 and main support rail 21 so that its inner edge engages the body of the preform as it progresses between the augers. This frictional contact encourages rotation of the preform in a counterclockwise direction when viewed from above.

[0181] Also, the gaps in the guide rails 17 are roughly coextensive with the length of the auger screws 25. Any rotation of the handles already in a trailing state will simply force them into engagement with the opposite guide rail 15, leaving them trailing. However, as can be seen from the close-up inset of FIG. 4D, the handles of the preforms with leading handles at the entrance between the auger screws will be gradually rotated from their leading handle positions to a position where they are in a trailing position (allowed to rotate freely by the gaps in the guide rails 17) until they are prevented from further rotation by the opposite guide rail 15. From here, as can be seen from FIGS. 4C and 4D, the preforms (all with trailing handles) proceed down the main support rails 19 and 21, with the handles now constrained between successive guide rails 15 and 17, until they reach their final orientation at the feeder wheel 36.

[0182] As the preforms pass between the auger screws 23 and 25, not only do they space and rotate the preforms, but the rotation rate of the auger screws is such that they are synchronized with the rotation of the feeder wheel 36 to deliver the preforms to that wheel. Moreover, the rotation of the auger screws provides pressure to ensure that the preforms progress down the main support rail.

[0183] Transfer to preheat 5 and 6, a first rotary transfer system 42 is positioned adjacent to the feeder wheel 36 such that the continuously rotating carrier 44 of the first rotary transfer system 42 and the feeder wheel 36 rotate in a counter-rotating manner relative to each other.

[0184] In this embodiment, the rotating carrier 44 of the first rotating transfer system 42 includes four opposing support arms 46 that extend radially from a fixed center of rotation 48 and rotate about a vertical axis 50. Each end of the arms carries a first pick and place device 52. Each first pick and place device 52 includes a linear guide 54 and a housing 56 that is rotatably mounted to the outer end of the support arm 46 and allows rotation of the housing 56 about the vertical axis 51. A two-finger gripper 58 is mounted to a rotary actuator 60 that is supported by a vertical plate 62 at the outer end of a free-slide element 64 of the linear guide 54. The gripper fingers 66 are centered on the gripper effective vertical axis 68 such that the gripper can be rotated about the horizontal axis 61 of the rotary actuator 60.

[0185] A fixed horizontal cam plate 70 is mounted at a level below the rotating carrier 44 so that its centre is coincident with the rotating carrier's vertical axis 50. A peripheral edge 72 of the cam plate 70 defines an outer cam surface 74 and an upper surface 76 thereof is provided with a cam channel 78 which lies inboard of the peripheral edge 72 and the outer cam surface 74.

[0186] The housing 56 of the linear guide 54 is provided with an outrigger arm 80 that extends radially from a center of rotation 82 of the linear guide 54. The outer end of the outrigger arm 80 supports a first cam follower 84 that is located in the cam channel 78. The free-slide element 64 (adapted for reciprocating linear movement in a horizontal plane) is provided with a second cam follower 86 that is biased by a spring 88 to maintain contact between the second cam follower 86 and the outer cam surface 74.

[0187] The cam channel 78 and outer cam surface 74 are arranged such that as the first pick and place device 52 rotates past the preform pick-off location 26, rotation of the rotating carrier 44 in combination with the trajectory of the first and second cam followers 84, 86 causes the gripper 58 to be both reciprocally extended and retracted and rotated relative to the arm 46. The gripper motion is such that on approaching the preform pick-off location 26, the free slide element 64 (and thus the gripper 58) is extended, followed by rotation of the linear guide 54 and gripper 58 in a counter or negative direction relative to the direction of rotation of the rotating carrier 44.

[0188] At the moment when the preform 12 arrives at the pick-off position 26 after its approximate orientation (so that the handle 20 of the preform is trailing but not yet fixed), the extension movement of the gripper 58 through the first cam follower 84 relative to the outer cam surface 74 makes the gripper effective axis 68 coincident with the central axis of the preform. At this moment too, a pair of opposing actuators positioned below the pick-off position 26 simultaneously close for a short period on the preform handle 20 and then release it, fixing its orientation to the gripper 58, which also at that moment engages the neck 18 of the preform. The gripper 58 is then rotated positively, carrying the preform 12 away from the supporting short rail 40 and away from the pick-off position 26.

[0189] This combination of reciprocating rotation and extension and retraction of the gripper 58 compensates for the divergence of the supporting tooth formation 38 of the feeder wheel 36 and the trajectory of the rotating carrier 44 as they counter-rotate one relative to the other. The reciprocating rotation and retraction movement of the gripper through the combination of the rotating linear guide and the two cam trajectories allows for a smooth and continuous transfer of the preforms between the two rotating elements (the rotating elements of the feeder wheel 36 and the rotating carrier 44).

[0190] Loading onto the mandrel stage 7, rotation of the rotating carrier 44 brings the preforms 12 held in the grippers 58 into the preheat stage 28 of the machine 10 as shown in FIG. 3. Because preheating of the preforms is performed with the preforms inverted from their initial position at the pick-off location 26 (i.e., with the necks 18 facing up), the rotary actuator 60 at the end of the free-slide element 64 rotates the grippers 58 and the preforms through 180 degrees during their transition between the pick-off location 26 and the transfer to the preheat transport system 90. The effect of this rotation is that the handle 20 of the preform is now in a "leading" position relative to the direction of rotation of the rotating carrier 44, rather than the trailing position it was in at the pick-off location 26 as can be seen in FIG.

[0191] The preheat transport system 90 also has continuous motion and includes a loop rail system 92 with proximal and distal rotatable guide wheels 94 and 96, respectively, at either end of the loop. A plurality of preform support mandrels 98 are adapted to move around the loop rail system 92 and are driven by a drive chain (not shown) to which they are secured for movement around the straight sections of the loop, and are driven for movement around the guide wheels 94, 96 by being placed into niches 103 of the guide wheels. In addition to traveling around the loop rail system 92, the mandrels 98 are rotated continuously about a vertical axis.

[0192] Preheating of the preform 12 is required to sufficiently soften the polymer in the body 16 of the preform (i.e., that portion of the preform that will undergo stretching and blow molding). However, the handle 20 and neck 18 (which will retain their as-injection-molded configuration in the blown container shown in FIG. 3) must be protected from excessive heat as the preform moves through the preheating stage. For this reason, as shown in FIG. 8, the preform support mandrel 98 is provided with a heat shield 100 that includes a channel 102 rising from a cylindrical collar 104 in which the handle 20 is protected, while the neck 18 is protected by its insertion into the cylindrical collar 104 of the mandrel.

[0193] As shown in FIG. 5, it can be noted that the pattern of the outer cam surface 74 of the first rotating transfer system 42 near the pick-off position 26 and the pattern of the cam channel 78 are different from the pattern on approach to and following the transfer of the preform to the preheating position 106. This reflects the difference in the movement required of the gripper 58 as it steers the preform into a position where its vertical axis is aligned with the vertical axis of the cylindrical collar 104 of the mandrel 98 and the handle 20 is aligned with the heat shield channel 102. At the moment when these axes are aligned and the handle 20 of the preform is aligned between the side elements of the channel 102, the cylindrical plunger 108 in the collar 104 rises into the neck 18 and then lowers to bring the neck into an insertion position in the collar. Of course, these movements are performed while the first rotating transfer system 42 and the proximal guide wheel 94 are continuously counter-rotating. This complex movement is again made possible by a combination of rotation of the arm 46 and rotational and linear movement of the free-slide element 64 (and thus the gripper fingers 66 of the first pick and place device 52).

[0194] Thus, the transfer of the preform from the gripper of the first transfer system 42 to the preform support mandrel 98 is accomplished in one fluid motion as the preform's vertical axis is brought into alignment with the mandrel's vertical axis and the preform's oriented handle slides into the heat shield, accommodating each of the rotations of the loop rail, mandrel, and transfer system, as well as the movement of the gripper.

[0195] Pre-heating the preform As best seen in Figures 3 and 8, banks 110 of heating elements 109 are positioned along each of the straight sections of the loop rail system 92. Graded hot air 111 is drawn across the path of the preform 12 by extractor fans 113. A cooling air stream 115 is directed at the collar to prevent excessive heat buildup in the cylindrical collar 104 and the neck portion 18 of the preform therein.

[0196] As the mandrels 98 and preforms 12 are rotated away from the preheat transfer location 106 by the proximal rotating guide wheel 94, the mandrels supported in the chains of the preheat transport system 90 travel along a first straight section 112, around the distal rotating guide wheel 96, and back along a second straight section 114 to arrive at the mandrel-to-mandrel transfer location 116. While traversing these straight sections, the mandrels are rotated about their vertical axes by the mandrel gears 105 engaging the chains 107, uniformly exposing the bodies of the preforms to heat from a bank 110 of heating elements 109. The heating elements 109 are each arranged as a series of infrared heating elements that are individually adjustable for their proximity to the passing preforms.

[0197] It will be appreciated that the orientation of each mandrel 98 at both the to-preheat transfer position 106 and the from-mandrel transfer position 116 is important to enable the respective first and second transfer systems to insert and extract the preform handles into and from the channels in the mandrel's heat shield. These heat shield orientations relative to the periphery of the proximal guide wheel 94 are not the same in these two positions, such that the orientation of the mandrel and its heat shield needs to be changed from that required in the handle extraction position to that required in the handle insertion position.

[0198] For this purpose, each mandrel is provided with a guide carriage 98a which is fixed to the mandrel. As the mandrel approaches the from-mandrel transfer position 116, cam followers 98b and 98c engage the guide channels and rotate the mandrel into the required orientation. During the transition around the periphery of the proximal guide wheel 94, the cam followers 98b and 98c follow the cam channels of the cam plate above the proximal guide wheel to bring the orientation of the heat shield into the required orientation at the transfer position 106 to preheat.

[0199] Transfer to molding 9, the second rotary transfer system 118 operates to transfer the preforms 12 from the preheat transport system 90 to a stretch blow molding die assembly 120. The stretch blow molding die assembly 120 includes four stretch blow molding dies 30, two of which can be seen in the cutaway view of the machine in FIG. 9. In this embodiment, the four radially disposed stretch blow molding dies 30 rotate continuously about a common center 122.

[0200] The second rotational transfer system 118 is of a similar configuration to that of the first rotational transfer system 42 described above, that is, it includes a cam plate 124 which is also provided with an inboard cam channel 126 and an outer cam surface 128 about its periphery.

[0201] In this instance, the second rotating transfer system 118 includes two (instead of four) continuously rotating opposing radial arms 130, each of which carries a second pick and place device 132. Again, similar to the first pick and place device 52 of the first rotating transfer system 42 described above, each includes a linear guide rotatably mounted to the outer end of the respective radial arm 130, with a free-sliding element of the linear guide supporting a rotary actuator, which in turn supports a gripper. In this arrangement, too, a first cam follower of the outrigger arm, which is attached to the housing of the linear guide, is located in the inboard cam channel 126, while a second cam follower of the free-sliding element of the linear guide is kept in contact with an outer cam surface 128 by a spring.

[0202] The preform, still held in the preform support mandrel 98, arrives back on the rotating proximal guide wheel 94 of the preheat system, approaches the mandrel transfer position 116, and is rotated into the required orientation of the heat shield as described above. The cylindrical plunger 108 of the mandrel 98 approaching the mandrel transfer position 116 lifts the preform, keeping its neck out of the cylindrical collar 104 and allowing the gripper of the second rotating transfer system 118 to engage the preform with the exposed neck 18. Again, the gripper motion induced by the combination of the rotation of the radial arm 130, the rotation of the linear guide, and the linear movement of the free-slide element supporting the gripper as controlled by the cam channel 126 and the outer cam surface 128 allows the preform and its handle to be smoothly removed from the preheat transport system 90.

[0203] As one rotating radial arm 130 of the second rotating transfer system 118 approaches the preform and removes it from the preheat transport system 90, the opposing radial arm approaches the die loading position 134. During its rotation from the mandrel transfer position 116 to the die loading position 134, the rotary actuator of the second pick and place device 132 rotates about its horizontal axis to change the preform from its inverted position in which it was held during the preheat stage back to an upright position (it should be noted that FIG. 9 shows both the rotating arm 130 and the stretch blow molding die 30 approaching the die loading position 134).

[0204] The stretch blow molding die of the die assembly 120 is in the form of two die halves 136, one of which is shown in Figure 10. The die halves 136 are hinged together in a clamshell fashion about a vertical axis 142 with the hinges supported from a central structure 146 of the die assembly 130 in a typical arrangement for a radial stretch blow molding machine. The face surfaces 138 of the die halves shown in Figure 10 are shaded to highlight the die cavity 148 for the body portion 16 and integral handle 20 of the preform. As is common in stretch blow molding of containers, the neck portion 18 (which remains unchanged in the stretch blow molding process) protrudes from the die when closed.

[0205] 9, as the stretch blow molding die 30 approaches the loading position 134, the die halves open symmetrically about a bisecting radial line 152 that passes through the center of rotation 122 and the vertical axis 142 of the die hinge 144 in preparation for receiving a preform. It may be noted from FIGS. 3 and 9 that the centers of rotation of the second rotational transfer system 118, the preheat stage proximal rotational guide wheel 94, and the stretch blow molding die assembly 120 lie along a straight line 154.

[0206] As the open die 30 approaches the die loading position 134 lying on the straight line 154, the radial arm 130 with the preform held in the gripper of the second pick and place device 132 also approaches the loading position. When the bisecting radial line 152 of the die half 136 becomes coincident with the straight line 154, the movement of the second pick and place device 132 causes the gripper effective vertical axis (and thus the vertical axis of the preform) to coincide with the axis 156 of the die (as defined by the center of the preform body when held in the die) and with the handle oriented to lie in the vertical plane defined by the straight line 154. As the die halves close and the paths of the ends of the die 30 and rotating arm 130 begin to diverge, rotation and extension of the gripper (still holding the neck 18 of the preform) ensures that the orientation of the handle is maintained in that vertical plane defined by the die halves bisector until closure of the die halves is complete. The gripper then releases the preform neck.

[0207] It can be seen from Figure 10 that the curved section of the handle 20 of the preform is placed into a shrink cavity 150 of the die, which ensures that the handle is not distorted and also ensures that the area between the joining points 22, 24 is not stretched. The underside of the straight section of the handle forms a surface which actually determines the shape of the container below the handle.

[0208] With the die halves 136 closed, stretch blow molding of the container proceeds and the die 30 loaded at the die loading position 134 rotates towards the die unloading position 158 as shown in FIG.

[0209] Container Unloading A third rotating transfer system 160 is positioned adjacent to the stretch blow molding die assembly 120 and is configured in a manner similar to that of the first and second rotating transfer systems 42, 132 described above. Like the second rotating transfer system 132, the third rotating transfer system 160 includes opposing radial arms 162 with a third pick and place assembly 164 at each end of the opposing radial arms 162. However, it does not include a rotary actuator because the container emerging from the die remains in an upright position throughout the dispensing process.

[0210] As with the first and second rotary transfer systems, the movement of the gripper 166 is controlled by a combination of the rotation of the opposing radial arms 160, the linear movement of the free element of the linear guide, and two cam trajectories.

[0211] As the stretch blow molding die 30 (now containing the finished container 14) approaches the die unloading position 158, which lies on a line 168 joining the center of rotation of the stretch blow molding die assembly 120 and the center of rotation of the opposing radial arm 160 of the third transfer system, the pick-and-place gripper is maneuvered into position to grip the neck of the container. When the die reaches the die unloading position, the die halves open and the gripper extracts the blown container 14 from the die 30.

[0212] The third rotating transfer system 160 continues to rotate, taking the container 14 held by the gripper 166 into the discharge channel 172 with the base of the container passing over the guide rail 170. The guide rail 170 transitions from concentric with the third rotating transfer system to concentric with the rotating two-tiered outfeed wheel 172. When the container 14 (now in the discharge channel 172) reaches a release position 174 that overlies a line 176 joining the center of rotation of the third rotating transfer system 160 and the center of rotation of the outfeed wheel 172, the gripper 166 releases the neck and retracts. At the same time, the scalloped recess 172a of the rotating outfeed wheel captures the body of the container and feeds it into the discharge channel 172. As the container follows the path of the gripper 166 and then the path determined by the outfeed wheel 172, the base of the container receives cooling air from orifices 182 in the guide rail 170 and back pressure from the container that builds up in the discharge channel 172 forces the container to fall into a container receiving bin 180 or, in the case where the container is transported to a filling and capping machine, as shown in FIG. 38, onto a conveyor 178.

[0213] Machine Control The operation of the machine 10 is under the control of a programmable logic controller. As well as ensuring that all rotary drive servo motors operate in synchronism, the controller provides full adjustability of the preheat element parameters and of the stretch blow molding die parameters. This includes setting differential temperature gradients that allow for gradually increasing exposure to heat as the preforms progress around the preheat transport system, and also includes automatic adjustment of the heating element temperature to accommodate changing room temperatures.

[0214] Control of preheat is particularly important in the present system due to the unique nature of the preform, which is dictated by its integral handle. Thus, the preheat is designed to allow lateral flow of material in the area between the two join points of the handle, while limiting longitudinal flow and elongation during the stretching phase of the stretch blow molding process. Instead, the manner in which heat is applied to the preform ensures that the bulk of the polymer that forms the outer shell of the container of FIG. 2 is produced from that region of the preform below the lower join point of the handle.

[0215] FIG. 12 is a schematic block diagram of control components associated with controlling the heating and transport of preforms that can be used with any of the embodiments described above.

[0216] As best seen in the inset of Figure 12, a bank 110 of heating elements 109 is positioned along each of the straight sections of the loop rail system 92. A gradient of hot air 111 is drawn across the path of the preform 12 by an extractor fan 113. A cooling air stream 115 is directed at the collar to prevent excessive heat buildup in the cylindrical collar 104 and the neck portion 18 of the preform therein.

[0217] In a preferred embodiment, each bank 110 includes modules 201. The modules 201 are arranged sequentially around a conveyor 202, as shown in FIG.

[0218] In a preferred embodiment, a processor 203 in conjunction with a memory 204 executes a program for control of the heating element 109 of the module 201 .

[0219] In a particularly preferred embodiment, each element 109 of each module 201 is individually controlled by a processor 203 .

[0220] In an alternative preferred form, the elements 109 are controlled as a group based on height, so that the elements 109 at the top of the module 201 are controlled together to a predetermined temperature, while the next lower element 109B in height is also controlled together to a predetermined temperature, down to element 109G at the lowest level.

[0221] In addition, the processor 203 controls the speed of rotation of the motor 205 to control the continuous speed of the preform 16 .

[0222] A temperature sensor 206 (in one form, an infrared temperature sensor) provides environmental temperature sensing that is utilized by the processor 203 to modulate the degree of heating of all elements 109 by a difference factor delta (Δ).

[0223] This allows for global control of the system temperature in response to room temperature fluctuations.

[0224] As mentioned above, stretch blow molding machines have been developed and adapted specifically for feeding and transporting an asymmetric preform with an integral handle, and ultimately stretch blow molding the preform into a container with an integral handle. Preforms according to the invention can take a number of different forms, which are described below, but common to all are the neck portion 18 and integral handle 20 as shown in FIG.

[0225] The preforms described herein differ primarily with respect to the configuration of their internal surfaces, offering the benefits of improved distribution of polymer material to the walls of the blown container and significantly improved manufacturing economics due to the reduced volume of polymer required.

[0226] First Preferred Asymmetric Preform Embodiment In a first preferred embodiment, a preform 310 according to the present invention as shown in Figure 13A includes a finished neck portion 312 and a tubular hollow body portion 314 extending downwardly from the neck portion. As with prior art preforms, the outer surface of the body portion 314 is defined by a diameter centered on a central vertical axis 316 such that the body portion 314 approximates a cylinder, but with a decreasing diameter from the neck portion 312 to the closed end 318 of the preform.

[0227] The interior surface of the preform 310 includes a surface of the hollow body portion 314 that is not concentric with the exterior surface. Preferably, as shown in Figures 15 and 16, the cross sections of the interior surface of the preform 310 are circular and concentric at the neck portion 312 of the preform, as shown by cross section AA, but below the neck portion are of an oval configuration, as shown by cross section BB. However, all cross sections are centered on the central longitudinal axis 316 of the body portion of the preform.

[0228] 14, in a preferred arrangement, the mandrel 322, around which the preform 310 is injection molded, includes an upper region 324 of circular cross section adapted to position and hold the mandrel in its correct position within the injection mold cavity. A first preform-defining portion 326 of the mandrel extends from this upper region 324 to a depth equal to the depth of the neck portion 312 and is of circular cross section AA as shown in FIG. 15, forming the concentric walls of the neck portion. An oval portion 328 of the mandrel depends from the first portion 326 and extends to a tip 330 of the mandrel.

[0229] Given the oval shape of the cross-section of oval section 328, immediately below section 326 which forms the interior configuration of the neck section, there is a short transition section of the mandrel which transitions from the circular cross-section AA of section 326 to the oval cross-section BB. This transition thus takes the form of an asymmetrical frustum of a cone whose upper end has a diameter equal to the diameter of the lower end of first section 326, and whose lower end fits in cross-section with the upper end of the oval section BB of the remaining length of the preform.

[0230] It can be seen from FIG. 13A that both the outer surface of the body portion 314 of the preform and the oval portion of the inner surface as defined by the mandrel 322 are tapered, i.e., the diameter defining the outer surface of the preform decreases from below the neck portion 312 to the base 318, while similarly the major and minor axes 344, 342 of the cross section of the oval portion 328 decrease accordingly.

[0231] 13A, the preform 310 of the present invention, as discussed above, further includes an integral handle 334 which forms a loop of material extending vertically from an upper juncture 336 below the neck portion 312 to a lower juncture 338 with the outer surface of the preform. The handle 334 is centered on and defines a central vertical plane 340 (lying into the page) which contains the central longitudinal axis 316 of the preform.

[0232] The mandrel 322 (and thus the interior surface of the oval portion 328 ) is oriented relative to the handle 334 such that the long axis 344 of the oval cross-section BB lies in a central vertical plane 340 .

[0233] 16 and cross section BB, it can be seen that the wall thickness of the preform 310 in that portion 328 of the preform whose inner surface is defined by an oval cross section varies from a maximum at either end of the minor axis 342 of the oval cross section to a minimum thickness at the outer end of the major axis 344. Preferably, the ratio of the maximum to the minimum wall thickness of the oval portion is in the range of 2:1 to 2.2:1.

[0234] The distribution of polymer in the preform according to the invention, given by the asymmetry of the oval section, allows the polymer walls of the preform in the region of maximum thickness to be biased predominantly towards the long side walls 346 of the rectangular cross-section blown container 348, while the polymer walls of the preform from the region of minimum thickness are distributed predominantly towards the short side walls 350 of the blown container as shown in Figures 17 and 18. It can be seen from Figures 17 and 18 that the long side walls 346 lie on either side of the central vertical plane 340 (and thus the handle 334), and the alignment of the long axis 344 with the vertical plane 340 is such as to ensure that the polymer from the region of maximum wall thickness is directed towards those long side walls. In a preferred form, the preform of the first embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating, asymmetric preform feed stretch blow molding machine as previously described herein.

[0235] Second Preferred Asymmetric Preform Embodiment Referring now to FIG. 19, in this preferred embodiment, the exterior surface 410 of the preform 400 of this embodiment is of a substantially cylindrical configuration. As with the first embodiment above, it also includes an integrally injection molded handle 434. In this embodiment, the interior surface 414 of the preform is consistently circular in cross section, as shown in the two sample cross sections of FIG. 19A and FIG. 19B. However, again, as is clear from the two cross sections and the cross-sectional side view of FIG. 19, there is tapering of the interior surface 414, such that the wall cross section, although concentric with the exterior surface, increases from a minimum thickness at the neck portion 412 of the preform to a maximum thickness adjacent its lower end 418. In a preferred form, the preform of the second embodiment is produced by an injection molding process, as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine, as previously described herein.

[0236] Third Preferred Asymmetric Preform Embodiment In this further preferred embodiment of the invention, a preform 500 as shown in Figure 20 is formed to significantly reduce the volume of material required to create the container shown in Figures 17 and 18. As with the previous embodiment, the preform 500 includes an injection molded integral handle 534. In this embodiment, the neck portion 512 is identical to that of the previous embodiment with respect to its external and internal configuration, however, below the neck portion there is a substantial reduction in the diameter of the substantially cylindrical portion of the body of the preform.

[0237] In this embodiment, as in the second preferred embodiment above, the inner surface of the preform is consistently circular in cross section, as shown in the two sample cross sections A and B in Figures 20A and 20B, but is tapered, with an increasing wall section from a minimum thickness obtained at the neck portion, through the transition in diameter below the neck portion, to a maximum wall thickness adjacent the lower end 518 of the preform.

[0238] As an additional means of reducing the volume of material in the preform of this embodiment, the outer surface 510 below the neck portion 512 also tapers towards the lower end 518. In a preferred form, the preform of the third embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating, asymmetric preform feed stretch blow molding machine as previously described herein.

[0239] Fourth Preferred Asymmetric Preform Embodiment 21, this preferred embodiment of a preform 600 according to the present invention shares several attributes with those of the first and second preferred embodiments described above. It has an integral handle 634 as previously described (like all preform embodiments of the present invention), and like the first preferred embodiment above, the inner surface 614 of the preform is not of consistently circular cross-section throughout the length of the preform. However, the outer surface 610 of the preform is substantially cylindrical in shape, like the second preferred embodiment.

[0240] Thus, while the exterior surface 610 is defined by a circular cross-section, the interior surface 614 changes from circular in cross-section from the neck portion 612 to cross-section AA in FIG. 21A, and then transitions to an oval cross-section BB as shown in FIG. 21B approaching the lower end 618.

[0241] A feature of this particular embodiment is that the wall thickness of the oval portion of the interior surface 614 of the preform at the end of the major axis remains constant with the wall thickness of the concentric cross sections from cross section AA upwards, while there is wall thickening, increasing to a maximum at the minor axis of the oval cross section. In a preferred form, the preform of the fourth embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein.

[0242] Fifth Preferred Asymmetric Preform Embodiment The preform of this embodiment of preform 700 shown in Figure 22 is similar to that of the fourth preferred embodiment above, except that here, as shown in cross sections AA and BB in Figures 22A and 22b, the wall thickness at the outer ends of the major axis of the oval cross-sectional portion of the preform is not maintained equal to the wall thickness at and below the neck portion 712. Rather, the wall thickness gradually increases from below the neck portion towards the lower end 718 of the preform.

[0243] At this point it may be noted that shaping the internal surfaces in these non-concentric forms of outer and inner surfaces in those forms of preforms similar to this embodiment and that of the first preferred embodiment above introduces significant problems with regard to injection molding of the preforms.

[0244] As shown in Figure 24, preforms (including those of the present invention) are typically injection molded in a multi-cavity die 800 in which cavities 820 in the die conform to the exterior shape of the preform (including, in this case, the shape of the integral handle). For preforms with concentric wall thicknesses (i.e., with a circular cross-section), the mandrel 840 for forming the interior surface will also be of circular cross-section. Thus, the only requirement for positioning such a mandrel relative to the injection molding cavity is its concentricity with the neck portion of the cavity.

[0245] A mandrel for creating an internal surface of a preform that is totally or partially non-circular in cross-section, firstly, can require fairly complex machining operations, and secondly, it must be specifically oriented within the injection molding cavity.

[0246] The mandrel for a preform having a non-circular cross-section must be positioned in the cavity of an injection molding die 820, half of which is shown in Figure 24, so that the long axis of the oval portion is aligned with respect to the vertical center plane of the cavity. For a preform according to the invention with an integral handle, that vertical plane is the plane on which the handle of the preform is centered as described above (actually, the face 842 of the die half).

[0247] To be effective in forcing polymeric material flow from the different wall thickness areas of the preform towards the designated regions of the blown container, the orientation of the preform must be maintained within the cavity of the stretch blow molding machine; that is, the vertical plane of the preform must coincide with a defined vertical plane of the container. In the present invention, the vertical plane of the preform is defined by the integral handle and is made to coincide within the stretch blow molding cavity with the central vertical plane of the blown container (which, again, is the center of the integral handle of the container).

[0248] In a molding cycle, the die halves are brought together to close the die and an array of mandrels 840 are driven into the cavity 820. An injection nozzle 848 is then advanced into the injection pocket 844 and molten polymer is forced through a runner system 846, filling the space between the exterior surface of the cavity 820 and the mandrels 840 to create a preform.

[0249] While the above description has focused in some embodiments on the use of oval or offset cross sections to vary the wall thickness of at least a portion of the preform at any given cross section of that portion, it will be understood that such variation can be achieved by other non-concentric shaping of the mandrel. Again, while the oval cross sections described with respect to the preferred embodiment are centered on the vertical axis of the preform, other material distribution effects can be achieved by asymmetric positioning of these cross sections. In a preferred form, the preform of the fifth embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein.

[0250] Sixth Preferred Asymmetric Preform Embodiment In this further preferred embodiment of the preform according to the present invention and shown in FIG. 23, the preform 900 is provided with a wall thickness 911, specifically in the area between the joining points 936 and 938 of the integrally injection molded handle 934, to optimize the control of material in this area during the stretch blow molding stage which produces the container from the preform.

[0251] In this embodiment, the exterior surface 910 of the preform is again substantially cylindrical in shape. The interior surface 914 of the preform is similarly formed from a circular cross-section, but as can be seen in both the side cross-section view of Figure 23 and cross-section AA of Figure 23A, the center of a portion of the cross-section (represented by cross-section AA) is not on the central axis 930 of the body of the preform, but is offset towards the handle 934.

[0252] The effect is to "thin out" the wall thickness in the region between the handle junction points 936 and 938. This is possible and desirable, firstly because less volume of material is required to form the container since there is no longitudinal stretch in this region, and secondly because the thinning provides significant cost savings in material.

[0253] It will be appreciated that all the above embodiments of the preform seek to both optimize the distribution of the polymeric material of the preform into the blown container and do so by reducing the weight (and therefore the volume of material) for reasons of production economy. In a preferred form, the preform of the sixth embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein.

[0254] Seventh Preferred Asymmetric Preform Embodiment 26 and 27, a preform 1000 for stretch blow molding a container 1040 shown in Fig. 28 is comprised of a neck portion 1012, a collar 1014, and a body portion 1016 extending downwardly from the collar. Similar to the prior art preform shown in Fig. 1, the preform 1000 includes an integral handle 1018 that is bonded to the body portion 1016 at a first bond location 1020 immediately below the collar 1014 and at a second bond location 1022 along the length of the body portion.

[0255] A first cylindrical portion 1024 of the body which extends below the collar 1014 is of substantially constant diameter, and in the area directly below the collar, the diameter is substantially the diameter of the finished container, as can be seen in FIG.

[0256] First, however, it can be seen from a comparison of the preform 1000 according to the invention with the prior art preform that there is a significant reduction in the diameter of the body portion 1016 below the first cylindrical portion 1024.

[0257] Moreover, it is clear that this second portion 1026 of the body (between the tangent 1028 of the diameter reduction to the bottom portion 1030) is not cylindrical in shape, but forms part of a narrow cone, the base diameter 1030 of the cone (which is its largest diameter) being significantly smaller than the diameter of the first cylindrical portion 1024. This large reduction in diameter and tapering therefore provides a first significant reduction in the volume of PET contained within the preform of the present invention.

[0258] 27, the walls of the body portion 1016 of the preform 1000 vary considerably in thickness. The wall thickness of the neck portion 1012 and the first portion 1024 below the collar 1014 is of substantially constant thickness, while the wall thickness of the second portion 1026 varies from a relatively thin wall section at the base diameter 1030 to a maximum thickness adjacent the tangent line 1028.

[0259] The wall thickness of bottom portion 1032 is further varied, decreasing from a maximum thickness at tangent line 1028 to a minimum thickness at the base of the bottom portion.

[0260] This reduction in wall thickness in the region below maximum diameter 1030 of second portion 1026 enhances the diameter reduction and material volume reduction provided by the configuration of second portion 1026 .

[0261] In addition to providing savings in material volume, these variations in wall thickness are designed to distribute the PET material volume evenly to various areas of the wall of the stretch blow molded container 1040 shown in Figure 28, to an average thickness of approximately 0.5 mm. In a preferred form, the preform of the seventh embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein.

[0262] Eighth Preferred Asymmetric Preform Embodiment Referring to Figures 33, 34 and 35, a preform is illustrated having an integral handle with a flared portion, thereby providing an ergonomic aspect to lifting the container blown from the preform.

[0263] 33, in a preferred form of the preform, preform 2100 includes a neck portion 2102, a body portion 2103, and a handle 2113. Neck portion 2102 has a threaded portion 2104 and a locating ring 2105. The preform is injection molded from a PET material as taught elsewhere herein. The handle in its configuration as injection molded in its preform state remains unchanged by the stretch blow molding process which forms the container resulting from a continuous blow molding process as described elsewhere herein.

[0264] To create a container, the preform 2100 shown in Figures 33 to 35 is fed into a blow molding machine (such as machine 10 shown diagrammatically in Figure 3) and blown according to a biaxially oriented blow molding technique. During this process, the neck portion 2102 is held in a mandrel 322 (as shown in Figure 14) of the transport system of the machine 10 to prevent its expansion in the stretch blow molding die 30.

[0265] The loop of orientable material forming the handle 2113 has a generally uniform cross-section from a position adjacent the lower connection region 2116 to a gradually diverging cross-section 2124 which approaches the upper connection region 2115 with the cross-section reaching and maintaining a maximum width adjacent the upper connection region 2115, as can be seen in Figures 34 and 35.

[0266] Referring again to FIG. 33, integrally molded first, second and third reinforcing elements 2135, 2136 and 2137 are provided, respectively, at each of the upper connection region 2115, the lower connection region 2116 and the junction between the straight section 2118 and the arcuate section 2120 of the handle 2113.

[0267] The first reinforcing element 2135 in the upper connection region 2115 comprises a curved reinforcing element that generally matches in width and cross-section to the width and cross-section of the widened portion 2124 of the handle proximate the upper connection region. The curved reinforcing element extends from a first separate connection region 2140 on the body portion 2103 of the preform (and on the blown molded container) below the upper connection region 2115 and merges with the loop of orientable material proximate the widest first end 2141 of the handle.

[0268] The second reinforcing element 2136 in the lower connection region 2116 of the handle comprises a straight reinforcing element that generally matches in width and cross-section to the width and cross-section of the straight section 2118. The straight reinforcing element extends from a second separate connection region 2142 above the lower connection region 2116 of the straight section of the handle and blends with the straight section of the handle adjacent the lower connection region.

[0269] The third reinforcing element 2137 at the junction of the straight section 2118 and the arcuate section 2120 of the handle comprises a further curved reinforcing element that generally matches in width and cross-section to the width and cross-section of both the straight section 2118 and the arcuate section 2120 of the handle adjacent the junction, the outer ends of each of the further curved elements blending with the straight section 2118 and the arcuate section 2120, respectively.

[0270] It should be noted that in this case, the width of the first reinforcing element 2135 is the same as the maximum width of the widened part 2124 of the handle proximate the upper connection region 2115. It is this increased width of the first reinforcing element 2135 that provides a larger area for distributing the load of the container over the index finger of the hand (not shown) lifting the container, with the curvature of the first reinforcing element being selected to comfortably fit the average index finger of a human hand.

[0271] Preferably, each reinforcing element 2135, 2136, and 2137 includes a web of orientable material within the boundaries formed between the body portion 2112 of the preform and the first and second reinforcing elements 2135 and 2136, and between the third reinforcing element 2137 and the straight section 2118 and the arcuate section 2120, respectively. Each web of orientable material is aligned with the handle centerline 2132 and extends equally in both directions from the handle centerline 2132. In a preferred form, the preform of the eighth embodiment is produced by an injection molding process, as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine, as previously described herein.

[0272] Ninth Preferred Asymmetric Preform Embodiment Referring to FIG. 36, a ninth embodiment of a preform is illustrated showing an alternative cross-sectional arrangement for the purpose of reducing the volume of the preform. In this case, similar components are numbered as in the fourth embodiment with reference to FIG. 21. In this case, the cross-sectional wall profile as shown in sections AA and BB is rotated 90 degrees compared to the wall profile of FIG. 21. In a preferred form, the preform of the ninth embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein.

[0273] Tenth Preferred Asymmetric Preform Embodiment Referring to FIG. 37, a tenth embodiment of a preform is illustrated showing an alternative cross-sectional arrangement for the purpose of reducing the volume of the preform. In this case, similar components are numbered similarly to the fifth embodiment with reference to FIG. 22. In this case, the cross-sectional wall profile as shown in sections AA and BB is rotated 90 degrees compared to the wall profile of FIG. 22. In a preferred form, the preform of the tenth embodiment is produced by an injection molding process as previously described herein. In a preferred form, the preform so produced is reheated and blown on a continuously rotating asymmetric preform feed stretch blow molding machine as previously described herein. Differential wall thickness system

[0274] 38, 39, and 40, a blown molded container having variable wall thickness as a function of radial angle in a horizontal plane and as a function of location of the horizontal plane through the blown molded container 950 is illustrated.

[0275] The variation can be achieved by selection of the preform wall thickness from among the various preform profiles previously described herein.

[0276] Also, by construction of the interior of the blow mold to support and encourage differential stretch blow molding of different regions of the preform when the walls of the preform positioned within the blow mold are stretched both horizontally and vertically to the extent permitted by the interior walls of the preform cavity and the cavity into which the handle 950 is placed, variations in wall thickness of the blow molded container can be achieved independent of the preform wall thickness profile.

[0277] In a further aspect, control of the wall thickness of the blown molded container is achieved through a combination of preform wall thickness selection and blow mold cavity design.

[0278] In yet a further aspect, control of the wall thickness of the blown container is achieved by control of the temperature profile of the preform wall immediately prior to introduction into the blow mold cavity.

[0279] This control can be achieved by the shape of the shield that covers the handle of the preform during the reheat phase.

[0280] This control can be achieved by adjusting the timing of the preform's progression through the reheat phase.

[0281] Referring to FIG. 38, a PET container 950 is shown having a neck portion 951 and a body portion 952, where a PET handle 953 is integrally connected to the body portion 952; the PET handle 953 is integrally connected to the container at at least a first connection point 954; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip 955 of PET material is positioned above the container 950 below the PET handle 953.

[0282] FIG. 38 further illustrates a PET container having a neck portion and a body portion, where a PET handle is integrally connected to the body portion; the PET handle includes an elongated portion of PET material integrally connected to the container at at least a first connection point; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip of PET material is positioned on the preform and corresponding container opposite the elongated portion of PET material.

[0283] FIG. 38 further illustrates a PET container having a neck portion and a body portion, where a PET handle is integrally connected to the body portion; the PET handle is integrally connected to the container at at least a first connection point; the PET container is blown from a PET preform in a stretch blow molding process; and a region in the form of a strip of PET material is positioned opposite the PET handle and over the preform and corresponding container.

[0284] Preferably, the handle 953 and the narrow strip 955 form a solid mass 956 , thereby maintaining an integral connection between the handle 953 and the blown molded container 950 .

[0285] Preferably, the integrally connected handle and narrow strip form a solid connected mass, thereby enhancing the integral connection between the handle and the blown molded container.

[0286] Thus, in a further broad form of the invention, there is provided a PET container stretch blow moulded from a preform, the preform and container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle including an elongated portion of PET material integrally connected onto the body portion of the preform and onto the container at at least a first connection point; the PET container being blown from the PET preform in a stretch blow moulding process; a region in the form of a strip of PET material being positioned on the preform and corresponding container opposite the elongated portion of the PET material handle; and the strip of material being differentiated in thickness from the thickness of the wall of the container on the side opposite the connection point.

[0287] Preferably, the handle and the narrow strip form a solid mass, thereby maintaining an integral connection between the handle and the blown molded container.

[0288] Preferably, the elongate portion of PET material comprises a stem.

[0289] Preferably, the PET handle is connected to the container at a second connection point.

[0290] Preferably, the first connection point is the upper connection point.

[0291] Preferably, the second connection point is the lower connection point.

[0292] Preferably, the preform has a neck portion and an expandable portion positioned below the neck portion.

[0293] Preferably, the area of ​​the preform body defined by the strip between the two attachment points remains substantially stable during stretching and blow molding of the container.

[0294] Preferably, both the outer surface layer and the area of ​​the inner surface layer laterally spaced from the narrow strip undergo biaxial orientation.

[0295] Preferably, the outer surface of the narrow strip remains substantially stable, while the walls and inner layers of the container in the strip between the handle attachment points experience some flow and thinning along with the surrounding areas as the plasticized PET material comes under the influence of stretching and blow molding forces.

[0296] Preferably, the PET handle is formed in the same mold as the preform and at the same time as the preform is molded.

[0297] Preferably, the loading of plastics material in a region of the wall defined between the first and second locations is differentially controlled as a function of location on the periphery of the wall in this region.

[0298] Preferably, the region is designated a differential loading region.

[0299] Preferably, there is an increased loading of material in the area directly between the first and second location points, while an opposing area located diametrically opposite the differential loading area has reduced material thickness and removed therefrom, as shown in dotted outline.

[0300] Preferably, differential material loading as a function of circumferential position on the wall of the preform helps provide control of the wall thickness of the blown container.

[0301] Preferably, the stretch blow molding process is a two stage stretch blow molding process.

[0302] Preferably, the differential loading region defined between the first location and the second location remains substantially unchanged during the blow molding process.

[0303] Preferably, the differential loading area is an extension of the neck portion of the preform and a portion of the neck portion of the preform.

[0304] Preferably, the preform includes a symmetrical thickening of the wall of the preform in a lower region of the body portion extending from just below the point of connection of the lower end of the handle.

[0305] Preferably, in a second intermediate region located between the first and second connection points of the handle, the wall thickening of the preform gradually tapers from a first thickness T1 to a second, thinner thickness T2.

[0306] Preferably, the thickening is symmetrical about the longitudinal axis of the preform.

[0307] Preferably, the thickening results in a controllable increase in the thickness of the material in the blown molded container in the corresponding intermediate region and also in the sub-region directly below the first connection point at the lower end of the handle.

[0308] Preferably, the thickening results in a controllable increase in the thickness of the material in the blown molded container in the corresponding intermediate region and also in the sub-region directly below the second connection point at the lower end of the handle.

[0309] 42, there is shown a preform 1410 that is injection molded entirely from PET plastic. In this instance, the preform includes an integral PET handle 1426, which in this instance is connected at least at an upper connection point 1422. In this particular instance, the handle 1426 is also connected at a lower connection point 1424.

[0310] As with the previous embodiment, the wall thickness of the preform can be differentiated throughout the preform to achieve a particular end wall thickness of the container 1428 blown therefrom (see FIG. 43).

[0311] In particular, the wall thickness 1421A in the region of the preform 1420A located under the handle 1426 and on the side of the preform nearest the handle 1426 can be differentiated from the wall thickness 1441A in the region 1440A located on the opposite side of the preform from the region 1420A. The intent is to control the preform wall thickness such that the wall thickness 1421B in the region of the container 1420B located under the handle 1426 and on the side of the container nearest the handle 1426 can be differentiated from the wall thickness 1441B in the region 1440B located on the opposite side of the container 1428 from the region 1420B, and the wall thickness at the corresponding location on the blown container 1428.

[0312] The resulting differentiated wall thickness in the blown molded container can be achieved by selection of wall thickness in the preform 1410. In an alternative embodiment, the resulting differentiated wall thickness in the blown molded container can be achieved by selective migration of PET in the wall during the stretch blow molding process. In certain embodiments, both methodologies can be used together.

[0313] In a particular embodiment, region 1420B is blown against a substantially planar inner wall 1460 of a blow mold 1461 (see inset in FIG. 43) such that region 1420B itself constitutes a substantially planar region.

[0314] In a particularly preferred form, the upper connection point 1422 is positioned above a non-expanded region 1470 A of the preform that corresponds to a substantially non-expanded region 1470 B of the resulting blown container 1428 .

[0315] In a particularly preferred embodiment, where the lower end of the integrated handle 1426 is integrally connected to the preform at a lower connection point 1424, the lower connection point is connected to a substantially planar region of the blown molded container 1410.

[0316] In this embodiment of the preform and container blown therefrom with reference to Figures 42 and 43, a region of the wall of the blown container is differentiated in thickness from the reduced wall thickness diametrically opposite the handle by an increased loading of material in that region. Region 1420B can be substantially planar.

[0317] In certain configurations, the rigid handle 1426 and the substantially planar region form a rigid interconnected structure that resists bending of the handle 1426 relative to the container 1428 during use. This feature may be particularly advantageous for larger volume containers 1428, such as a four liter container where the weight of the liquid in the container may be significant.

[0318] In one form, during the stretch blow molding operation, region 1420A / 1420B remains substantially stable while regions laterally on either side of it undergo bidirectional stretching.

[0319] A PET container stretch blow molded from a preform, the preform and container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle including an elongated portion of PET material, the elongated portion integrally connected at least at a first connection point onto the body portion of the preform and onto the container; an area in the form of a planar area located on the container opposite the handle; and the planar area differentiated in thickness from the thickness of a wall of the container on the side opposite the handle.

[0320] Preferably, the handle and the planar area form a solid mass, thereby maintaining an integral connection between the handle and the blown molded container.

[0321] Preferably, the integral handle includes a stem.

[0322] Preferably, the PET handle is connected to the container at a second connection point.

[0323] Preferably, the first connection point is the upper connection point.

[0324] Preferably, the second connection point is the lower connection point.

[0325] Preferably, the preform has an expandable portion located below the neck portion.

[0326] Preferably, the area of ​​the preform body defined by the substantially planar area between the two attachment points remains substantially stable during stretching and blow molding of the container.

[0327] Preferably, the PET handle is formed in the same mold as the preform and at the same time as the preform is molded.

[0328] Preferably, the loading of plastic material in the area of ​​the wall 1420A / 1420B defined between the upper and lower connection points is differentially controlled as a function of location on the periphery of the wall in this area; that area is designated the differential loading area.

[0329] Preferably, there is an increased loading of material in the area directly between the first and second location points, while an opposing area located diametrically opposite the differential loading area has a reduced material thickness.

[0330] Preferably, differential material loading as a function of circumferential position on the wall of the preform helps provide control of the wall thickness of the blown container.

[0331] Preferably, the stretch blow molding process is a two stage stretch blow molding process.

[0332] Preferably, the differential loading region defined between the first location and the second location remains substantially unchanged during the blow molding process.

[0333] Preferably, the differential loading area is an extension of the neck portion of the preform and a portion of the neck portion of the preform.

[0334] A bifurcated reinforcement system With reference to Figures 42 and 43, as well as to the embodiment of the differential wall thickness system described above, additional features can be added to the integral handle of that embodiment to further strengthen its connection to the body of the container 1428.

[0335] In this embodiment as shown in Figures 42 and 43, the handle 1426 includes a curved reinforcing element 1481 at the lower end of the handle. In one instance, the reinforcing element 1481 is located at the junction between an arcuate section 1482 and a straight section of the handle 1483. In this region, the orientable plastic material is bifurcated to form a surrounding generally triangular element 1484, which may include a matching generally triangular shaped central web.

[0336] Similar bifurcated and preferably web-like reinforcing elements 1485 and 1486 may be provided in the upper and lower connection regions, respectively.

[0337] The combination of the connections to the substantially planar regions 1420A, 1420B and the reinforcing elements 1485 and 1486 provides a closed, rigid structure that provides confidence to the user, especially when the container is of a relatively large volume.

[0338] A Note About the Handle In a preferred form, the integral handle of the preform is not substantially deformed or substantially changed in shape during the stretch blow molding process, and retains substantially the shape as it is injection molded. The blow mold cavity shown in Figure 10 includes a recess specifically shaped to the shape of the handle as it is injection molded. It will be appreciated that a primary function of the heat shield is also to protect the handle from heat that may cause distortion of the handle as the preform is transported around the preheat stage of the machine.

[0339] Preform injection molding A suitable system for injection molding any one of the preforms described above will now be described with reference to Figures 29 to 31. As noted elsewhere, the integral dual-connected handle of a container that is stretch blow molded from a preform introduces significant complexity into the design and operation of the injection molding tool.

[0340] Typically, in injection molding of preforms for symmetrical or unhandled containers, the body of the preform below the neck is formed in a cavity in the "hot" stationary section of the injection molding die, and the threaded neck portion is formed in an opposing half-cavity carried on the face of the moving die section. After the molding cycle, when the die opens, the body of the preform is pulled out of its cavities by the neck, which in this first opening stage is held in the still closed opposing half-cavity and moves with the opening die section. The opposing half-cavities now part, releasing the neck, and the stripper plate is activated to push the preform out of the core (which is fixed to the moving die section).

[0341] 29 to 31, for a preform 1100 with a handle 1112, only its section 1114 below the handle can be formed in a cavity 1116 in a heated, fixed section 1118 of a die 1120, with the neck 1122 and handle 1112 being formed in a much longer and more complex opposing half-cavity 1124 carried on a moving die section 1126. Again, a core 1128 for forming the internal shape of the preform 1100 is fixed to the moving die section 1126 and positioned on the common axis of the cavity 1116 and the opposing half-cavity in the heated, fixed side of the die.

[0342] In contrast to demolding of a symmetric preform, whose body is immediately exposed to air as the die opens, a much larger section of the preform of the present invention is retained within the opposing half-cavities 1124 and therefore requires a longer delay before the preform cools and becomes stable enough to peel away the core 1128. This significantly increases the mold cycle time for preforms with handles.

[0343] To reduce cycle time and therefore increase production, in a system of the invention, now referring to FIG. 32, a robot 1130 (only a portion of its arm is shown in FIG. 32) is used in demolding the preform 1100. The robot arm end effector 1132 is fitted with an array 1134 of vacuum cups 1136, which are equally spaced apart according to the number and spacing of cavities in the injection molding die as shown in FIG. 31. Towards the end of the molding cycle, this array 1134 of vacuum cups is poised above (or to the side of) the injection molding die 1120, and as soon as the die has opened sufficiently to allow insertion of the array, the robot brings the array into registration position between the parted sections 1118 and 1126 of the die and advances the vacuum cups 1136 to fit over the lower ends of the preforms.

[0344] It is important for the correct extraction of the preform that the handle remains aligned in its as-molded orientation and prevents rotation of the handle into a position where it may catch on the edge of the opposing cavity half. For this reason, the vacuum cup is provided with a slot or channel 1138 at its outer end, which slides around the lower end of the handle. By this means, a larger portion of the preform is also covered by the vacuum cup. Now, a vacuum is applied to the cup 1136 and the robot retracts the array 1134, the preform 1100 now secured in the cup by the vacuum pressure, extracting the preform from the core. Once free from the core, the vacuum cup array and the held preform are pulled from between the heated fixing section 1118 and the moving side 1126 of the die and rotated so that the axis of the preform is in a substantially vertical orientation. The vacuum pressure is then cut, allowing the preform to drop from the vacuum cup into a receiving bin.

[0345] The advantage of using a vacuum in the demolding process rather than a conventional stripper plate is that the application of the vacuum helps to cool the preforms significantly, thus allowing them to be extracted at an earlier point in the mold cycle, shortening the cycle. This is particularly beneficial for the preforms of the present invention, where the lower end of the handle (which is the last part of the preform to be formed (the injection proceeding from the tip of the closed end of the preform)) is at the highest temperature when the die opens. Additionally, the slot or channel that accommodates the lower part of the handle provides for a larger portion of the preform to receive the cooling provided by the air flow into the suction cup when the vacuum is applied just before the suction cup completely encapsulates the lower and middle portions of the preform.

[0346] Further cooling occurs as the robot pulls the array of vacuum cups and preforms away from the die and over a receiving bin. The array is then rotated from its initial position as it was removed from the die location (i.e., with the preform axes horizontal) to a vertical position, allowing the preforms to drop from the cups into the receiving bin when the vacuum pressure is cut.

[0347] Single connect integral handle for PET containers and method of production PET polymer is an expensive material to create what is in the main single-use bottle. Of course, there are well-known advantages of PET. Firstly, the transparency of the material, which allows a clear view of the contents of the container, and secondly, the material is suitable for recycling. However, it is not possible, or at least very complicated, to provide an integral handle in a PET stretch blow molded container (such as a handle provided by molding around a hole in the side of the bottle, as is commonly provided in HDPE containers).

[0348] Besides its aesthetic appeal, a PET container provided with an integral handle would add a desirable feature in the ease of handling of the container. Some solutions are known, in which a separately injection molded handle is positioned in a stretch blow molding cavity and the container is blown such that the end of the handle is captured by the material flowing around it (e.g., as disclosed in patent application publication no. 2010-274967). However, these arrangements are complex and difficult to implement in practice.

[0349] As best seen in FIG. 1, a significant volume of polymer is expended in the bracing structure at the upper and lower connection areas 22, 24, as well as at the intersection 30 of the handle's arcuate portion 32 and straight lower part 34, to provide the strength needed for secure connection of the loop of the handle 26 to the container 28 of FIG.

[0350] 44 and 45, the integral handle 40 of the preform 42 and container 44 of the present invention is connected to the cylindrical body portion 46 of the preform. It will be noted that in this configuration of the handle 40, it has been found that there is no need for increased wall thickness at the connection region 48 or in the region 50 extending below the connection region, and in effect the wall thickness of the cylindrical body portion 46 of the preform is uniform. Again, that uniform wall thickness is carried over into the container 44 of FIG. 45 blown from the preform of FIG. 44.

[0351] In this instance, the handle 40 includes an upper arcuate portion 52 extending from the single connection region 48, which transitions into a substantially straight downwardly projecting portion 54. The handle 40 includes a central web 56 that lies in a plane passing through a centerline 58 of the preform body portion. The web 56 is bounded by a continuous edge 60 around the periphery of the web from an upper attachment point 62 to a lower attachment point 64 on the preform body portion 46.

[0352] The handle 40 further comprises ribs 66 which are perpendicular to the web 56 which extends along the edge 60. The ribs 66 project outwardly and symmetrically from both sides of the plane such that, in effect, the web 56 and the ribs 66 form an I-beam-like cross section. The upper and lower cross sections of the ribs 66 extend to blend with the surfaces of both the preform and the container. These areas of the ribs and central web combine to provide the strength of the handle-to-container connection required to manipulate the filled container.

[0353] In some preferred embodiments, the inwardly facing sections 68 of both the web 56 and the ribs 66 are provided with one or more scallops configured to aid in gripping the handle by a user. Also, preferably, in some embodiments, the handle may be additionally provided with a thumb support 70, such as that shown on the container in FIG. 45, protruding from an upper portion of the rib.

[0354] Significant savings in PET polymer are realized over prior art dual-connection handles by the handle 40 being connected at a single connection area on both the body portion of the preform and the body of the container stretch blow molded from the preform, which allows for a reduction in wall thickness in the area of ​​the handle connection such that the wall thickness in the area of ​​the handle connection is substantially equal to the wall thickness in adjacent areas of both the preform and the container.

[0355] FIG. 46 is a side cross-sectional view of a further example of a preform with a handle attached at a single point with an alternative variable wall profile.

[0356] In this case, preform A10 has a sidewall having a first, relatively thin thickness A11 near the neck end of the preform and a second, relatively thicker thickness A12 near the lower end of the preform furthest from the neck A13.

[0357] In this case, a first relatively thin wall thickness transitions to a relatively thick wall thickness via a transition zone A14, as shown in FIG.

[0358] In this case, the inner wall diameter A15 decreases as a function of the length of the preform, gradually decreasing away from the neck portion A13, thereby producing a transition zone A14 and a wall thickness of the relatively thick wall portion A12.

[0359] In this case, the outer wall diameter A16 either remains relatively constant as a function of the length of the preform, or in alternative versions, increases slightly as a function of length away from the neck portion A13.

[0360] The end result is a preform with a relatively thick wall thickness furthest from the neck. In a preferred form, this provides increased material for stretch blow molding to form a relatively enlarged volume blow molded container blown from preform A10. The rationale for the location of wall thickening in preforms intended for stretch blow molding as part of a two-stage stretch blow molding process or system is explained in the technical literature (see, for example, "Plastic Blow Moulding Handbook," N.C. Lee, Springer Netherlands Publishing, May 31, 1990, especially pages 101-107 thereof).

[0361] FIG. 47 is a side cross-sectional view of a further example of a preform with a handle attached at a single point with an alternative variable wall profile.

[0362] In this case, preform A20 has a sidewall having a first, relatively thin thickness A21 near the neck end of the preform and a second, relatively thicker thickness A22 near the lower end of the preform furthest from the neck A23.

[0363] In this instance, a first relatively thin wall thickness transitions to a relatively thick wall thickness via a transition zone A24, as shown in FIG.

[0364] In this case, the inner wall diameter A25 either remains relatively constant as a function of the length of the preform, or in alternative versions, increases slightly as a function of length away from the neck portion A23.

[0365] In this case, the outer wall diameter A26 increases as a function of the length of the preform, gradually increasing away from the neck portion A23, thereby producing a transition zone A24 and a relatively thick wall thickness A22.

[0366] The end result is a preform with a relatively thick wall thickness furthest from the neck. In a preferred form, this provides increased material for stretch blow molding to form a relatively enlarged volume blow molded container blown from preform A10. The rationale for the location of wall thickening in preforms intended for stretch blow molding as part of a two-stage stretch blow molding process or system is explained in the technical literature (see, for example, "Plastic Blow Moulding Handbook," N.C. Lee, Springer Netherlands Publishing, May 31, 1990, especially pages 101-107 thereof).

[0367] In the case of the single connect handles A17, A27 shown in Figures 46 and 47, the single connect being positioned higher on the preform near the necks A13, A23 allows for more flexibility in wall thickness design and optimal use of PET material, as previously explained.

[0368] Preform distortion control and method Figures 48 and 49 show an injection molded preform 10 with an integrally connected, in this case doubly connected, handle 14, as it was initially injection molded and then distorted following passage through a preheat conditioning stage of a stretch blow molding machine. As can be seen in Figure 49, substantial distortion of the preform can occur due to the asymmetry of the preform introduced by the integrally connected handle. Bending of the body portion 12 of the preform pulls the handle out of its as-injection molded position.

[0369] Within limits, distortion of the cylindrical body 12 of the preform is not a major concern as long as movement of the stretch rods is not compromised, but in stretch blow molding of preforms with integral handles, the handles must not be distorted to an extent that they cannot be properly inserted into pockets in the stretch blow molding die where they are intended to maintain their configuration during the stretch blow molding cycle.

[0370] To produce a stretch blow molded container as shown in FIG. 51 (where the handle has the desired configuration), it is necessary, first, to reduce the distortion to within a manageable minimum range, and, second, to adapt the stretch blow molding die to contain the distortion within this minimum range.

[0371] In a preferred embodiment of the invention, the minimum range of distortion is established by repeated test runs in which injection molded preforms 10 are passed through the tuning stages of the machine with carefully controlled and adjusted parameters. These parameters can include the settings and placement of heating elements, temperature gradients at various locations, time of pass and rotation of the preform, etc. These test runs will establish the repeatable minimum range of distortion for a given set of parameters, around which a strategy can be devised to control handle distortion.

[0372] The heat shields that protect the handles from excessive heat as the preforms pass through the preheat stage must be designed to accommodate maximum distortion within the minimum distortion range.

[0373] In one arrangement, the design of the integrally connected handle of the injection molded preform and the cavity of the preform injection molding die can be adjusted such that, at least to some extent, the distortion induced by the adjustment stage is intended to return the handle to a desired configuration for entry into the handle pocket in the opposing cavity of the stretch blow molding die.

[0374] Distortion can be further accommodated by specific shaping of the periphery of the handle receiving pocket. As shown in FIG. 50, the handle nesting pocket 16 in each die half 18 is provided with an angled lead-in surface 20 to guide and urge the distorted handle into its proper seating position in the pocket 16. In this arrangement, the outer edge 22 of the lead-in surface 20 is such that it defines at least the maximum distortion of the range of distortion. By these means, a container such as that shown in FIG. 51 can be produced with an integral handle in its correctly designed arrangement on the blow molded container.

[0375] The same strategy for compensating for a singly connected one-piece handle can be employed as shown in Figures 52 and 53. As with the doubly connected handle, the singly connected handle 114 of the preform 100 will be distorted from its as-injection molded position by distortion of the body portion 112 of the preform.

[0376] As described above, strategies for establishing the minimum range of distortion (possibly adjusting the preform design and providing special lead-in surfaces 120 for the handle nesting pockets 116 in the die halves 118) can be deployed to produce the final stretch blow molded container of FIG. 53. [Industrial Applicability]

[0377] The initial feeding of previously injection molded asymmetric preforms into the machine 10 and their successive movement through the various successively rotating stages described above provides a significant improvement in the output and quality of containers stretch blow molded from such preforms. This continuous flow from the preform infeed to the container outfeed is made possible by the unique features of the machine's transfer system and the control of the orientation of the preform handles at each transfer, as well as the control of the orientation of the preform support mandrels at the transfer into and away from the preheat stage.

[0378] The preform of the embodiment described above provides for stretch blow molding of a container in a stretch blow molding machine, which is equivalent in volume to that of the container of Figure 25, but with a significant reduction in the volume of PET, and confers optimal distribution of material from the preform to form the container shown in Figures 17 and 18. Thus, the preform of the present invention provides a significant reduction in raw material costs in the production of PET containers with integral handles. [Explanation of symbols]

[0379] 10 Machine, preform 11 Roller 12 Preform, main body part 13. Roller 14 container, double connected handle 15 Guide rail 16 Preform body, handle nesting pocket 17 Guide rail 18 Neck section, die half 19 Main Support Rail 20 Integrated handle, installation surface 21 Main Support Rail 22 First joining point, outer edge 23 Auger screw 24 Second Junction Point 25 Auger screw 26 Pickoff Position 27 Flute 28 Preheating stage 29 Friction Strips 30 Stretch Blow Molding Die 32 Inclined Rail 32a Upper rail 32b Lower Rail 33 Drive Wheel 34 Escapement 34A Orientation Mechanism 34b Handle Orientation Mechanism 35 Drive Wheel 36 Feeder Wheel 37 Gap 38 Supporting Tooth Formation 39 Tires 40 Short rail, integrated handle 40a Stop 42 First Rotary Transfer System, Preform 44 Rotating carriers, containers 46 Support arm, main body part 48 Rotation center, connection area 50 Vertical axis, region extending below the connection region 51 Vertical axis 52 First pick and place device, upper arcuate portion 54 Linear guide, substantially straight downward protruding portion 56 Housing, central web 58 Gripper, centerline 60 Rotary actuator, edge 61 horizontal axis 62 Vertical plate, upper joining point 64 Free sliding element, lower connection point 66 Gripper fingers, ribs 68 Gripper effective axis, inward facing section 70 Horizontal cam plate, thumb support 72 Peripheral edge 74 Outer Cam Surface 76 Upper Surface 78 Cam Channel 80 Outrigger arm 82 Rotation Center 84 1st Cam Follower 86 Second Cam Follower 88 Spring 90 Preheating Transport System 92 Loop Rail System 94 Proximal Rotation Guide Wheel 96 Distal Rotation Guide Wheel 98 Preform Support Mandrel 98a Guide carriage 98b Cam Follower 98c Cam Follower 100 Heat shield, preform 102 Heat shield channel 103 Niche 104 Cylindrical collar 105 Gear 106 Preheat position 107 Chain 108 Cylindrical plunger 109 Heating Element 110 Bank 111 Hot Air 112 First straight section, body of preform 113 Extractor fan 114 Second straight section, single connected handle 115 Cooling Air Stream 116 Transport position, handle nesting pocket 118 Second Rotary Transfer System, Die Half 120 Stretch Blow Molded Die Assembly, Introduction Surface 122 Rotation Center 126 Cam Channel 128 Outer Cam Surface 130 Radial Arm 132 Second pick and place device 134 Loading Position 136 Die Half 138 Die half face surface 142 Vertical axis 144 Die hinge 146 Central structure 148 Die Cavity 150 Shrinkage Cavity 152 Bisector radial line 154 Straight Line 156 Die axis 158 Dianne loading position 160 Third Rotary Transfer System 162 Radial Arm 164 3rd Pick and Place Assembly 166 Gripper 168 lines 170 Guide rail 172 Outfeed wheel, discharge channel 172a Scalloped depression 174 Release position 176 lines 178 Conveyor 180 Container Receiving Bin 182 Orifice 201 Module 202 Conveyor 203 Processor 204 Memory 205 Motor 206 Temperature Sensor 310 Preform 312 Neck section 314 Main body part 316 Center vertical axis 318 Closed end 322 Mandrel 324 Upper area 326 First Part 328 Oval part 330 Tip 334 Integrated Handle 336 Upper joint 338 Lower joint 340 Center vertical plane 342 Short axis 344 Long axis 346 Longer side wall 348 Container 350 Shorter side wall 400 Preforms 410 External Surface 412 Neck part 414 Internal surface 418 Lower end 434 Handle 500 preforms 510 Outer surface 512 Neck part 514 Internal surface 518 Lower end 534 Integrated Handle 600 Preforms 610 External Surface 612 Neck part 614 Internal surface 618 Lower end 634 Integrated Handle 700 Preforms 710 External Surface 712 Neck part 714 Internal surface 718 Lower end 734 Integrated Handle 800 Multi-Cavity Die 820 Cavity 840 Mandrel 842 Die half face 844 Ejection Pocket 846 Runner System 848 Injection Nozzle 900 Preform 910 External Surface 911 Wall thickness 914 Internal surface 930 Center axis 934 Handle 936 Junction Points 938 Junction Points 950 container 951 Neck part 952 Main body part 953 PET Handle 954 First Connection Point 955 Strip 956 Solid Mass 1000 preforms 1012 Neck part 1014 Color 1016 Main body 1018 Integrated Handle 1020 First joint position 1022 Second joint position 1024 First cylindrical part 1026 Second Part 1028 tangent 1030 Bottom part 1032 Bottom part 1040 Container 1100 Preform 1112 Handle 1114 Lower section of handle 1116 Cavity 1118 Heated Fixed Section 1120 Die 1122 Neck 1126 Die moving side 1128 cores 1130 Robot 1132 Robot Arm End Effector 1134 Array 1136 Vacuum Cup 1138 slots, channels 1410 Preform 1420A area 1420B area 1421A Wall Thickness 1421B Wall Thickness 1422 Upper connection point 1424 Lower Connection Point 1426 Integrated Handle 1428 Container 1440A area 1440B area 1441A Wall Thickness 1441B Wall Thickness 1460 Inner wall 1461 Blow Mold 1470A Preform non-expanding area 1481 Reinforcement Element 1482 Circular Section 1483 Handle 1484 Generally triangular elements 1485 Reinforcement Element 1486 Reinforcement Element 2100 Preform 2102 Neck 2103 Main body part 2104 Threaded Part 2105 Positioning Ring 2112 Main body part 2113 Handle 2115 Upper connection area 2116 Lower connection area 2118 Straight Section 2120 Circular Section 2124 Widening section 2132 Handle centerline 2135 First Reinforcement Element 2136 Second Reinforcement Element 2137 Third Strengthening Element 2140 First separate connection area 2141 First end 2142 Second separate connection area A10 Preform A11 First relatively thin thickness A12 Second relatively thick A13 Neck A14 Transition Zone A15 Inner wall diameter A16 Outer wall diameter A17 Single Connect Handle A20 Preform A21 First relatively thin thickness A22 Second relatively thick A23 Neck A24 Transition Zone A25 Inner wall diameter A26 Outer wall diameter A27 Single Connect Handle

Claims

1. 1. A PET container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle is integrally connected to the PET container at least at a first connection point; The PET container is blown from a PET preform in a stretch blow molding process; A PET container, wherein an area in the form of a strip of PET material is positioned on said PET container beneath said PET handle.

2. 1. A PET container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle comprises an elongated portion of PET material integrally connected to the PET container at least at a first connection point; The PET container is blown from a PET preform in a stretch blow molding process; A PET container, wherein a region in the form of a strip of PET material is positioned on said PET container opposite said elongated portion of PET material.

3. 1. A PET container having a neck portion and a body portion, a PET handle integrally connected to the body portion; the PET handle is integrally connected to the PET container at least at a first connection point; The PET container is blown from a PET preform in a stretch blow molding process; A PET container, wherein a region in the form of a strip of PET material is positioned on said PET container opposite said PET handle.

4. 4. The container according to any one of claims 1 to 3, wherein the PET handle and the narrow strip form a solid mass, thereby maintaining an integral connection between the PET handle and the blown molded PET container.

5. 4. The container according to any one of claims 1 to 3, wherein the integrally connected PET handle and the narrow strip form a solid connected mass, thereby enhancing the integral connection between the PET handle and the blown moulded PET container.

6. A PET container stretch blow molded from a preform, the preform and the PET container have a neck portion and a body portion; a PET handle integrally connected to the body portion; the PET handle comprises an elongated portion of PET material, the elongated portion being integrally connected onto the body portion of the preform and onto the PET container at at least a first connection point; The PET container is blown from a PET preform in a stretch blow molding process; a region in the form of a strip of PET material is positioned on said container opposite said elongated portion of the PET material handle; A PET container, wherein the strip of PET material is differentiated in thickness from a thickness of a wall of the PET container opposite the connection point.

7. 7. The container according to any one of claims 1 to 3 and 6, wherein the PET handle and the narrow strip form a solid mass, thereby maintaining an integral connection between the PET handle and the blown molded PET container.

8. 7. A container according to any one of claims 1 to 3 and 6, wherein the elongated portion of PET material comprises a stem.

9. 7. The container of any one of claims 1 to 3 and 6, wherein the PET handle is connected to the PET container at a second connection point.

10. 7. The container according to any one of claims 1 to 3 and 6, wherein the first connection point is an upper connection point.

11. 7. The container according to any one of claims 1 to 3 and 6, wherein the second connection point is a lower connection point.

12. 7. The container of claim 1, wherein the preform has a neck portion and an expandable portion located below the neck portion.

13. A container as described in any one of claims 1 to 3 and 6, wherein the area of ​​the preform body defined by the strip between the two attachment points remains substantially stable during stretching and blow molding of the PET container.

14. A container as claimed in any one of claims 1 to 3 and 6, wherein regions of both the outer and inner surface layers laterally spaced from the narrow strip are subjected to biaxial orientation.

15. 7. A container as claimed in any one of claims 1 to 3 and 6, wherein the outer surface of the narrow strip remains substantially stable, but the wall and inner layer of the PET container in the strip between the handle attachment points experiences some flow and thinning along with the surrounding areas as the plasticized PET material comes under the influence of stretching and blow moulding forces.

16. 7. The container of any one of claims 1 to 3 and 6, wherein the PET handle is formed in the same mould as and at the same time as the preform is moulded.

17. 7. A container as claimed in any one of claims 1 to 3 and 6, wherein the loading of plastic material in a region of the wall defined between the first position and the second position is differentially controlled as a function of location on the periphery of the wall in this region, said region being designated as the differential loading region.

18. 7. The container of any one of claims 1 to 3 and 6, wherein there is an increased loading of material in the area directly between the first position and the second position, while an opposing area located diametrically opposite the differential loading area has reduced material thickness and removed therefrom, as shown by the dotted outline.

19. 7. The container of any one of claims 1 to 3 and 6, wherein differential material loading as a function of circumferential position on the wall of the preform assists in providing control of the wall thickness of the blown molded PET container.

20. 7. The container of any one of claims 1 to 3 and 6, wherein the stretch blow molding process is a two-stage stretch blow molding process.

21. 7. The container of claim 1, wherein the differential loading area defined between the first position and the second position remains substantially unchanged during a blow molding process.

22. 7. The container of claim 1, wherein the differential loading region is an extension of the neck portion of the preform and a portion of the neck portion of the preform.

23. 7. A container as claimed in any one of claims 1 to 3 and 6, wherein the preform includes a symmetrical thickening of the wall of the preform in a lower region of the body portion extending from just below the point of connection of the lower end of the PET handle.

24. 7. The container according to any one of claims 1 to 3 and 6, wherein in a second intermediate region located between the first and second connection points of the PET handle, the wall thickening of the preform gradually tapers from a first thickness T1 to a second, thinner thickness T2.

25. 7. A container according to any one of claims 1 to 3 and 6, wherein the thickening is symmetrical with respect to the longitudinal axis of the preform.

26. 7. A container according to any one of claims 1 to 3 and 6, wherein the thickening results in a controllable increase in the thickness of the material in the blown moulded PET container in the corresponding intermediate region and also in a sub-region directly below the first connection point of the lower end of the PET handle.

27. 7. A container according to any one of claims 1 to 3 and 6, wherein the thickening results in a controllable increase in the thickness of the material in the blown moulded PET container in the corresponding intermediate region and also in the sub-region directly below the second connection point of the lower end of the PET handle.

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