Patent Description:
Attempts have been made to incorporate integral handles in PET and like injection blow moulded containers - for example see <CIT>, assigned to Tri-Tech Systems International, Inc. The parison or preform from which the handled bottles of <CIT> are produced is illustrated in <FIG>. To date, however, attempts to produce a practical, mass produced version of this arrangement have been unsuccessful. Instead, the best that appears to have been done in commercial practice is an arrangement whereby the blown containers are arranged to accept a clip on or snap on handle in a separate production step after the container itself is formed. See for example <CIT> and <CIT>.

Injection-stretch-blow moulding is a process in which the parison is stretched both axially and radially, resulting in biaxial orientation.

Biaxial orientation provides increased tensile strength (top load), less permeation due to tighter alignment of the molecules, and improved drop impact, clarity, and lightweighting of the container.

Not all thermoplastics can be oriented. The major thermoplastics used are polyethylene terephthalate (PET), polyacrylonitrile (PAN), polyvinyl chloride (PVC), and polypropylene (PP). PET is by far the largest volume material, followed by PVC, PP, and PAN.

The amorphous materials, e.g., PET, with a wide range of thermoplasticity are easier to stretch-blow than the partially crystalline types such as PP. Approximate melt and stretch temperatures to yield maximum container properties are:.

There are basically two types of processes for stretch-blow moulding: <NUM>) single-stage in which preforms are made and bottles blown on the same machine, and <NUM>) two-stage in which preforms are made on one machine and blown later on another machine.

Single-stage equipment is capable of processing PVC, PET, and PP. Once the parison is formed (either extruded or injection moulded), it passes through conditioning stations which bring it to the proper orientation temperature. The single-stage system allows the process to proceed from raw material to finished product in one machine, but since tooling cannot be easily changed, the process is best suited for dedicated applications and low volumes.

Oriented PVC containers most commonly are made on single-stage, extrusion-type machines. The parison is extruded on either single- or double-head units. Temperature conditioning, stretching, and thread forming are done in a variety of ways depending on the design of the machine. Many of the processes presently in use are proprietary.

Many oriented PET containers are produced on single-stage machines. Preforms are first injection moulded, then transferred to a temperature conditioning station, then to the blow moulding operation where the preforms are stretch-blown into bottles, and finally to an eject station.

With the two-stage process, processing parameters for both preform manufacturing and bottle blowing can be optimized. A processor does not have to make compromises for preform design and weight, production rates, and bottle quality as he does on single-stage equipment. He can either make or buy preforms. And if he chooses to make them, he can do so in one or more locations suitable to his market. Both high-output machines and low output machines are available. Heretofor two stage extrusion-type machines generally have been used to make oriented PP bottles. In a typical process, preforms are re-extruded, cooled, cut to length, reheated, stretched while the neck finish is being trimmed, and ejected.

It is an object of the present disclosure to produce a practical, readily implementable injection, stretch blow moulded container made from an orientable plastics preform material incorporating a handle joined in a loop at at least two points to the preform.

<CIT> describes a method of forming a container from bi-axially orientable plastics material and having an integral handle formed from a stem; said method comprising: (a) forming a preform having a neck portion and an expandable portion below the neck portion, said neck portion including a locating ring above the expandable portion and a solid stem of orientable thermoplastics material projecting from or near the neck portion or immediately below it and moulded integrally therewith, and (b) performing a blow moulding operation on said preform to expand the expandable portion to form the body of the container. Also disclosed is a container manufactured from a two stage injection stretch blow moulding process, said container including a graspable handle affixed at at least a first point to said container so as to form an enclosed area between the handle and the container and through which the fingers of a human hand may be passed.

<CIT> describes a preform, and a container blown therefrom in a modified two stage process is disclosed having a loop defining a handle portion of the resulting blown container and wherein the loop is integrally connected by both a first end and a second end to respective first location and second location of the preform during manufacture of the preform.

The invention is defined in the appended claim <NUM>.

There is described herein a preform for a container comprised of orientable plastics material and arranged so that the resultant blown container will include a handle or like support structure; said preform comprising a moulded structure having a neck portion and an expandable portion below the neck, at least one loop of orientable plastics material integrally connected at least a first end to a respective first location on said preform which when the container is formed constitutes said handle.

In another broad form of the disclosure there is provided a method of forming a container having an integral handle; said method comprising:.

Preferably, the neck portion includes a locating ring above the expandable portion.

Preferably, said container is formed from said preform in a two stage operation.

Preferably, said at least one loop of orientable plastics material is integrally connected at said first end to said first location and at a second end at a second location on said preform.

Preferably, the handle allows at least two fingers of the adult human hand to pass therethrough.

Preferably, the loop is formed so as to have an I-shaped cross-section at least throughout that portion of the stem where it projects from the external side of said tube.

There is also described herein a parison or preform for an injection stretch blow moulding process, said parison formed by an injection process including two separate points of injection.

Preferably, a first point of injection permits injection of non-recycled PET or like plastics material.

Preferably, a second point of injection permits injection of PET or like plastics material incorporating at least a portion of recycled material.

Preferably, said first point of injection is for the formation of that part of the preform which will be stretched during a stretch blow moulding operation on the preform.

Preferably, said second point of injection is for the formation of those parts of said preform which will remain unexpanded or substantially unexpanded in a stretch blow moulding operation on said preform.

In still a further broad form of the invention there is provided a container manufactured from a two stage injection stretch blow moulding process, said container including a graspable handle integrally affixed at at least a first point to said container so as to form an area between the handle and the container and through which the fingers of a human hand may be passed.

Preferably, said first point of connection comprises an integral connection between the handle and the neck portion of the container and is formed in a first stage of said two stage process.

Preferably, said graspable handle is integrally affixed at said at least a first point and a second point of interconnection to said container so as to form an enclosed area between the handle and the container and through which the finger of a human hand may be passed.

Preferably, said second point of connection is located on an expandable portion of said container.

Preferably, said second point of interconnection is located on a lower neck portion of said container at a substantially non-expanding part.

Preferably, said first and second points of connection are located on a substantially non-expanding part of said container.

Preferably, the container includes an elongated substantially non-expanding neck portion to which said loop is affixed. Preferably, the preform further includes a locating ring immediately below which is a first non-expanding region and below which is a second non-expanding region.

Preferably, the first non-expanding region is formed so as to be slightly raised or otherwise differentiated from the expandable portion of said preform.

Preferably, the second non-expanding region is not differentiated from the expandable portion of said preform.

Preferably, the loop includes a first rib integrally moulded therewith.

Preferably, said loop includes a second rib integrally moulded with and extending from said second non-expanding region.

Preferably, the preform further includes a rib connector integrally moulded with and extending from first non-expanding region and forming a continuous connection between said first rib and said second rib throughout the length of said loop.

Preferably, said second non-expanding region forms part of a temperature transition zone.

In the disclosed preform said first non-expanding region forms part of said temperature transition zone.

Preferably, deformation of said temperature transition zone takes place during a stretch blow moulding process.

Preferably, the preform is manufactured by a two stage injection moulding process wherein material is injected at different locations in the die to form a preform adapted to be composed from more than one type of material.

Preferably, during at least one stage of said two stage process an inner wall and outer wall of said preform is formed, said inner wall adapted to be made from a different material from said outer wall.

In a further broad form of the invention, there is provided a container stretch blow moulded from the preform.

In yet a further broad form of the invention there is provided a method of production as a two step process of an integral handle PET container from a preform which has a loop of orientable plastics material at least one loop of orientable plastics material integrally connected at least a first end to a respective first location on said preform; said method including the step of shielding said loop of said preform during preheating of said preform preparatory to a stretch blow moulding step.

Preferably, said at least one loop of orientable plastics material is integrally connected at said at least a first end to said first location and at a second end to a second location on said preform. Preferably, said at least a first end and said second end are substantially supported in a mould cavity against movement during the stretch blow moulding operation.

In still another broad form of the disclosure there is provided a container comprised of biaxially orientable plastics material manufactured from a two stage injection stretch blow moulding process; said two stage process comprising a first stage in which a preform is manufactured and a second stage in which said preform is reheated and biaxially stretched to form said container; said container including a graspable handle integrally affixed at at least a first point of connection to said container so as to form an area between said handle and said container and through which at least two fingers of a human hand can pass.

Preferably, said graspable handle is integrally affixed at said at least a first point of interconnection and a second point of interconnection to said container so as to form an enclosed area between the handle and the container and through which the finger of a human hand may be passed.

Preferably, said first point of interconnection and said second point of connection comprises an integral interconnection between the handle and the container and is formed in said first stage of said two stage process.

Preferably, the container further includes a locating ring at a neck portion thereof.

Preferably, the container further includes a first non-expanding region immediately below said locating ring.

Preferably, the container of further includes a second non-expanding region below said first non-expanding region.

Preferably, said first non-expanding region is formed so as to be slightly raised or otherwise differentiated from that portion of said container which is fully biaxially oriented during said second stage of said two stage process.

Preferably, said second non-expanding region is not differentiated from that portion of said container which is fully biaxially oriented during said second stage of said two stage process.

Preferably, minor expansion of said second non-expanding region takes place during said second stage of said two stage process.

Preferably, said handle includes a first rib integrally moulded with and extending from said locating ring.

Preferably, said handle includes a second rib integrally moulded with and extending from said second non-expanding region.

Preferably, the container further includes a rib connector integrally moulded with and extending from said first non-expanding region and forming a continuous connection between said first rib and said second rib throughout the length of said handle.

Preferably, said first non-expanding region forms part of a temperature transition zone.

Preferably, the container is manufactured by said two stage injection moulding process and wherein material is injected at different locations during formation of said preform during said first stage of said two stage process whereby said container can be composed from more than one type of material.

Preferably, during said first stage of said two stage process an inner wall and outer wall of said preform is formed, said inner wall made from a different material from said outer wall.

Preferably, the container further includes a discontinuity region as defined in the specification.

Preferably, said discontinuity region lies in a plane which lies at an acute angle to the horizontal, said discontinuity region extending substantially throughout the circumference of said container.

Preferably, said discontinuity region at its point closest to said handle is located between a first end and a second end of said handle.

There is also provided a preform from which the container is shown in a two stage process, said preform including more than one wall profile.

Preferably, said preform has a first wall profile closest to its neck followed by a second wall profile immediately there below and separated therefrom by a first transition zone.

Preferably, said preform further includes a third wall profile immediately below said second wall profile and separated therefrom by a second transition zone.

There is further provided an injection machine for the manufacture of a parison or preform in a first stage of a two stage process.

There is further provided a stretch blow moulding machine for the manufacture of a container having an integral handle.

There is further provided an injection machine for the manufacture of preforms having integral handles incorporated therein; said machine including moulds having a channel which permits PET material to flow into a stem portion which constitutes a handle in a container blown from a preform produced by said injection moulding machine.

Preferably, said channel of said mould includes a return portion whereby said stem is connected integrally at two points on said preform.

In another broad form of the disclosure, there is provided a blow moulding machine for blow moulding a container having an integrally formed handle; said container blow moulded from a previously injection moulded preform; said preform comprising a body portion and said integrally formed handle; said machine including a preform loading station at which said preform is oriented by a preform orienting apparatus.

Preferably, said machine further includes a preform loading station and a preform transporting system; said transporting system including a plurality of mandrels; each of said mandrels provide with a heat shield for at least partially covering said integrally formed handle.

Preferably, said preform orienting apparatus is adapted to aligning said integrally formed handle of a said preform, with said heat shield of said mandrel; the arrangement being such as to allow insertion of said handle into said heat shield when said preform is brought into engagement with said mandrel.

Preferably, said machine further includes apparatus for orienting said integrally formed handle of said preform for entry of said preform into a stretch blow moulding tool of said machine.

Preferably, said loading station includes an infeed rail; said infeed rail supplied with preforms from a preform supply source; an output end of said rail arranged to release individual ones of said preforms sequentially to said orienting apparatus.

Preferably, said body portion of said preform is presented to said orienting apparatus with the axis of said body portion substantially vertical.

Preferably, said orienting apparatus includes a cylindrical sleeve fixed relative to said output end of said infeed rail; said sleeve having an axis substantially vertical; said axis aligned with an axis of said body portion of a said preform when said preform is released from said infeed rail.

Preferably, said sleeve has an internal diameter adapted to allow passage through said sleeve of said body portion of said preform.

Preferably, said sleeve is provided with a slit in a wall of said sleeve; said slit having a width sufficient for passage therethrough of said integrally formed handle; said slit extending from a handle inlet opening at the upper end of said sleeve to a handle outlet opening at a lower end of said sleeve.

Preferably, said upper end of said sleeve is truncated so that at least portions of said upper edge of said sleeve are at a slope relative to said axis of said sleeve.

Preferably, said at least portions of said upper edge of said sleeve are arranged to slope from at least one high point on said upper edge to said handle inlet opening.

Preferably, said upper edge is divided into two sloping sections; each sloping section forming a sloping edge from said at least one high point to respective first and second sides of said inlet opening of said slit.

Preferably, respective said edges of said sloping sections meet said respective first side and second sides of said inlet opening in smoothly rounded corners.

Preferably, said slope of said sloping sections is sufficient to ensure said integrally formed handle of a said preform is forced by the weight of said preform to slide downwardly along a said sloping section; said preform rotating until said handle is aligned with said slit; said preform and said handle then free to fall through said sleeve and said slit.

Preferably, an indexing table is provided below said orienting apparatus; said indexing table provided with a plurality of nests spaced equally around the periphery of said table; each of said nests sequentially brought into alignment with said axis of said sleeve at successive indexes of said table.

Preferably, each of said nests, when in said alignment with said axis of said sleeve, is arranged to accept and retain a said preform falling into a nest from said orienting apparatus; said handle retained in said nest in an orientation imposed by said slit of said orienting apparatus.

Preferably, a said preform is ejected upwardly from a said nest at a suitable subsequent indexed location of said indexing table; said preform brought into engagement with one of a plurality of mandrels of a preform transportation system.

Preferably, each said preform is brought into engagement with a mandrel of said preform transportation system.

Preferably, each of said mandrels is provided with a handle protection shield; said shield partially enclosing said handle when a said preform is brought into engagement with a said mandrel.

Preferably, said mandrels are equally spaced along a recirculating conveying system; said conveying system driven incrementally in synchronisation with increments of said indexing table.

Preferably, each of said mandrels of said preform transportation system is adapted for rotation about the axis of said preform; each of said mandrels being brought into a predetermined orientation at said suitable subsequent indexed location of said indexing table such that said handle protection shield is correctly aligned to accept entry therein of a said integrally formed handle of said preform.

Preferably, length of said preform transportation system and said rotation of said mandrels is arranged so that the handle of each said preform is at said predetermined orientation when said preform is released from said mandrel.

Preferably, said mandrel and said handle of said preform are rotated into said predetermined orientation prior to said mandrel and said preform entering said blow moulding tool.

Preferably, said preforms are rotated during transportation by said preform transportation system past an array of preform heating elements. Preferably, said handle and said heat shield are nested in a cavity provided for said handle and said preform in said blow moulding tool.

Preferably, said handle and said heat shield are nested in separate cavities in said blow moulding tool.

In another broad form of the disclosure there is provided an apparatus for orienting a preform for stretch blow moulding a container; said preform comprising a substantially cylindrical body with an integrally attached handle; said apparatus including a sleeve provided with a slit and at least one sloping upper edge; said at least one sloping upper surface and said slit arranged so as to guide said integrally attached handle into alignment with said slit.

Preferably, said preform is dropped into said sleeve; the bore of said sleeve adapted to accept as a sliding fit said body of said preform; an underside of said handle coming into sliding contact with a said upper edge.

Preferably, slope of a said sloping upper edge is sufficient to induce rotation of said preform as said handle slides down said sloping upper edge; said rotation causing said integrally attached handle to come into said alignment with said slit.

Preferably, said slit is adapted to allow sliding passage of said handle when said handle is brought into alignment with said slit.

In another broad form of the disclosure, there is provided a heat shield for the protection of an integrally formed handle of a preform; said heat shield protecting said handle from excessive heat as a body portion of said preform is pre-heated prior to entry into a stretch blow moulding tool.

Preferably, said heat shield is attached to a mandrel of a preform transportation system; said heat shield adapted to at least partially enclose said handle. Preferably, said shield comprises side portions extending substantially over opposing sides of said handle; said side portions extending from opposing edges of a spine element attached to said mandrel; said spine element conforming to upper portions of said handle.

Preferably, edges of said side portions are shaped to selectively protect interconnection points of said handle from said excessive heat; portions of said side elements arranged to allow a sufficient gap for adequate heat penetration to a body region of said preform between said interconnection points.

In another broad form of the disclosure there is provide an apparatus for controlling the orientation of a mandrel of a stretch blow moulding machine; said mandrel adapted for supporting a preform comprising a body with an integrally attached handle; said apparatus adapted to lock said mandrel into an oriented state and unlock said mandrel into a freely rotating state.

Preferably, said mandrel is one of a plurality of mandrels of a preform transport system of said blow moulding machine.

Preferably, when said mandrel is in said oriented state said integrally attached handle may be inserted into a heat shield attached to said mandrel. Preferably, when said mandrel is in said oriented state said integrally attached handle is correctly oriented for entry into a blow moulding tool of said machine.

Preferably, when said mandrel is in said freely rotating state said mandrel may be driven into rotation by a drive mechanism of said machine engaging a rotation driving sprocket of said mandrel during a preform preheating stage.

Preferably, said mandrel is provided with spring-loaded pawl; said spring-loaded pawl adapted to engage with a notch located on a boss of said rotation driving sprocket; said spring-loaded pawl activated and deactivated by a lever mechanism contacting fixed cams provided at predetermined locations along said preform transport system. Preferably, said lever mechanism is activated to set said spring-loaded pawl into a potential locking state at a first of said predetermined locations; a rotary drive rotating said sprocket until said spring-loaded pawl engages said notch.

Preferably, said lever mechanism is activated to retract said spring-loaded pawl to return said sprocket to said freely rotating stage at a second of said predetermined locations.

In another broad form of the disclosure, there is provided an apparatus for controlling the orientation of an integrally formed handle of a preform during a preheating stage of a stretch blow moulding process; said apparatus including a mandrel provided with a shield for protecting said handle from excessive heat during said preheating stage.

Preferably, said mandrel is one of a plurality of mandrels attached to a twin-strand conveyor system; each said mandrel rotatably mounted between strands of said twin-strand conveyor.

Preferably, said preform is inserted into said mandrel at a preform loading location such that said handle is located within said shield.

Preferably, said conveyor system extends between said preform loading location and a preform unloading location.

Preferably, each said mandrel is urged into rotation between said loading location and said unloading location; said rotation derived from contact between a toothed pulley of said mandrel and a rack extending between said loading location and said unloading location.

Preferably, said mandrel completes a whole number of rotations between said loading location and said unloading location such that orientation of said shield at said unloading location is substantially identical to orientation of said shield at said loading location.

Preferably, orientation of said shield is maintained between the end of said rack before said unloading location and the start of said rack after said loading location; said orientation maintained by a guiding surface of said mandrel maintaining sliding contact with a fixed rail.

In another broad form of the disclosure there is provided a mandrel for support and selective heat shielding of a preform provided with an integral handle; said mandrel comprising a vertically oriented socket portion and a shield portion depending from said socket portion.

Preferably, said socket portion is adapted to accept insertion and retention therein of a neck portion of said preform; said shield portion adapted to accept insertion and at least partially shield said integral handle.

Preferably, said socket portion is provided with a resilient plug; said plug adapted to enter an open neck of said preform when an inverted said preform is urged upwardly to engage with said mandrel; said plug entering said open neck as a friction fit sufficient to support the weight of said preform.

Preferably, said preform handle orienting apparatus comprises a cylindrical sleeve provided with a slit along a wall of said sleeve; an internal diameter of said sleeve allowing passage through said sleeve of said body portion of said perform; width of said slit allowing passage therethrough of said integrally formed handle.

Preferably, an upper edge of said sleeve is sloped relative to an axis of said sleeve; said upper edge sloping from at least one high point to said slit. Preferably, a said preform is presented to said orienting apparatus with an axis of said body portion substantially aligned with said axis of said sleeve. Preferably, said slope of said upper edge is such as to ensure a said handle of a said preform is caused to slide downwardly along said slope until said preform and said handle rotate into alignment with said slit.

Preferably, transfer of said preform to said transportation system includes the steps of:.

Preferably, each mandrel of said transportation system is provided with a preform handle protection shield; each said mandrel rotated to a position wherein said protection shield is aligned with said preform handle when said preform is ejected from a said nest.

Preferably, rotation of each said mandrel is controlled such that orientation of said handle is correctly aligned for entry into said blow moulding tool at a point where said preform is released from said transportation system.

In another broad form of the disclosure there is provided a method and apparatus for preheating a preform; said preform comprising a body portion and an integrally attached handle; said method including the steps of:.

Embodiments of the present disclosure will now be described by way of example, with reference to the accompanying drawings, in which:.

<FIG> illustrates a prior art preform or parison by way of introduction.

<FIG> through to <NUM> illustrate preform and resulting containers and methods of manufacture thereof and machinery for manufacture thereof which can include multiple integral connection of the handle stem or loop to the preform and resulting container.

In this specification the term "integral connection" or "integrally connected" means a connection between the handle and the preform (and subsequently the corresponding connection on the container blown from the preform) which is made from the same material as the handle and the preform and is formed as an inherent part of an at the same time as the preform is formed.

All first embodiments are produced in a two stage process.

In particular forms, embodiments are produced in a modified two stage process as to be later described.

The two-stage process is the lowest-cost method to produce oriented PET containers. The two-stage process, which provides injection moulding of the preform and then shipping to blow moulding locations, allows companies to become preform producers and to sell to blow moulding producers. Thus companies that wish to enter the market with oriented PET containers can minimise their capital requirements. Two-stage stretch-blow moulding also can be used for production of oriented PVC containers. Preform design and its relationship to the final container remains the most critical factor. The proper stretch ratios in the axial and hoop directions are important if the container is to properly package its intended product. Exemplary ratios are as follows:-.

A container <NUM> usable with an embodiment of the disclosure is shown in <FIG>. It includes a neck <NUM> and an expanded portion <NUM>.

The neck <NUM> has a threaded portion <NUM> and a locating ring <NUM>. Moulded integrally with the ring <NUM> is a stem <NUM> having a first portion 15a extending outwardly from the ring <NUM> and a second portion 15b so inclined to the first portion 15a that it is nearly parallel to a vertical axis of the container <NUM>. In this instance, the first portion 15a subtends an angle of slightly more than <NUM>° to the wall <NUM> and the second portion subtends an angle of about <NUM>° to the wall <NUM>.

The particular shape of the stem <NUM> is selected so that when formed as a handle it may be grasped by fingers of the human hand.

The stem <NUM> terminates in a stem end <NUM> which faces generally downwardly in the general direction of closed end of the container <NUM>.

In this instance, the stem <NUM> is of I-shaped cross-section to combat unwanted effects arising at or near junction <NUM> of stem <NUM> with the ring <NUM> following a blowing operation on the preform <NUM>.

These unwanted effects particularly include stress effects and air inclusions resulting from non-uniform cooling through preform volumes of differing cross-section.

In this arrangement, the preform is made from PET and is prepared utilizing a heated mould.

In order to produce the container <NUM>, the parison or preform <NUM> (see <FIG>) according to an embodiment of the disclosure can be placed in a blow moulding machine (not shown) and blow moulded according to bi-axial orientation blow moulding techniques with the neck <NUM> being held in a mould in such a way as not to expand. Initially, the expandable portion of the preform below the neck can be mechanically stretched downwardly to the bottom of the mould and then the bulk of the preform can be blown outwardly by application of compressed air to the extent that a support portion <NUM> is formed around the stem end <NUM> such that an enclosed area <NUM> is formed between wall <NUM> of the container <NUM> and the stem <NUM> in the process of the formation by blow moulding of container <NUM>.

In a particular form, the enclosed area <NUM> is of sufficient cross-sectional area to allow at least two fingers of a human hand to be inserted therethrough and to grasp handle <NUM> so as to support the container <NUM>.

The blow moulding operation is carried out in such a way so as to provide a bottle or container having optimum strength by achieving biaxial orientation of the molecules of the preferred PET material as well as improved barrier properties to reduce oxidation.

In accordance with an embodiment disclosure, the neck <NUM> and handle <NUM> can be crystallised by overheating those parts of the preform. The crystallisation of the handle increases its rigidity which assists orientation of the preform and permits the use of less material.

Crystallisation of the neck and handle can be carried out by running hot oil over the neck and handle, applying an open flame or by blowing hot air.

The location of the handle <NUM> on the ring <NUM> ensures that there is minimum interference to the blow moulding process applied to the remainder of the preform. Either a one stage or two stage process can be used.

<FIG> illustrates the prior art preform or parison <NUM> of <CIT>. The concept of this prior art disclosure is to form a handle portion <NUM> from the locating ring of non-expandable portion <NUM> of the parison <NUM>.

With reference to <FIG> and with reference to the detailed description of the preferred embodiment this arrangement of <FIG> is modified according to the present disclosure in a number of respects.

Insets 2A, 2B and 2C show bulbous portions <NUM> forming part of stem end <NUM> in the shape, respectively of a downwardly extending hook 24a, a bulb 24b and an upwardly extending hook 24c.

These portions have in common a shape which is adapted to engage mechanically with a blown portion of the container <NUM> which is adapted to envelop the bulbous portion <NUM>.

The process by which the second stage blowing of the expandable portion <NUM> of parison <NUM> is effected so as to envelope the bulbous portion <NUM> of stem end <NUM> is a stretch blow, biaxial orientation process.

With reference to <FIG> a particular method of manufacture of the preform or parison <NUM> is illustrated. It includes a two stage process for the formation of the parison by an injection moulding process. In Stage <NUM> a first injection mould inlet <NUM> permits entry of plastics material for the formation of the expanded portion <NUM> of the parison <NUM> (expanded in the blow moulding stage of container formation, with reference to <FIG>).

In a second stage of the injection moulding process for the formation of parison <NUM> a second injection mould inlet <NUM> permits entry of plastics material for the formation of the non-expandable portion <NUM> of parison <NUM>.

The two stage injection arrangement is such that different plastics materials may be injected through first injection mould inlet <NUM> and second injection mould inlet <NUM>.

In a particular form the plastics material injected in first injection mould inlet <NUM> is non-recycled or substantially non-recycled plastics material whilst the plastics material injected into second injection mould inlet <NUM> is recycled or at least partially recycled plastics material.

This arrangement permits controlled use of proportions of recycled and non-recycled plastics material in order to achieve optimum economics in the construction of parison <NUM>.

In a modification of this arrangement the Stage <NUM> step can include the production of two walls in the non-expandable portion <NUM> comprising inner wall <NUM> and outer wall <NUM>. Inner wall <NUM> is made from virgin or non-contaminated PET material and acts as an insulation barrier with respect to wall <NUM> which can be made from recycled material <NUM>. This dual wall arrangement can be produced by use of a sliding core arrangement as a modification in the die arrangement and process described with reference to <FIG>, <FIG> and <FIG> later in this specification.

Of course the Stage <NUM> and Stage <NUM> steps of <FIG> can be interchanged in order.

A parison and resulting container according to a further arrangement are illustrated in <FIG> and B respectively. Like parts are numbered as for previous embodiments.

In this arrangement the parison <NUM> includes a locating ring <NUM> immediately below which is a first non-expanding region <NUM> and a second non-expanding region <NUM>. The first non-expanding region <NUM> may itself be formed so as to be slightly raised or otherwise differentiated from the expandable portion of parison <NUM>. Second non-expanding region <NUM> may not be differentiated from the expandable portion of parison <NUM> but, in use, the blowing operation will be such as to ensure that the second non-expanding region <NUM> is not expanded in the blowing process.

In this case the stem <NUM> includes a first rib <NUM> integrally moulded with and extending from locating ring <NUM>. The stem <NUM> also includes second rib <NUM> integrally moulded with and extending from second non-expanding region <NUM>. Stem <NUM> further includes a rib connector <NUM> integrally moulded with and extending from first non-expanding region <NUM> and forming a continuous connection between first rib <NUM> and second rib <NUM> throughout the length of stem <NUM>.

The parison <NUM> of <FIG> is then blown in the manner previously described to form the volume <NUM> of container <NUM> illustrated in <FIG>. The neck portion including stem <NUM>, ring <NUM>, first non-expanding region <NUM> and second non-expanding region <NUM> remain unexpanded whilst the expandable portion <NUM> of parison <NUM> is biaxially stretched to form the major volume <NUM> of container <NUM>. The stem end <NUM> may include the bulbous portions according to the previously described embodiments for connection to container <NUM> or, either alternatively or in addition can include the application of an adhesive material whereby a chemical bond is formed between stem end <NUM> and the wall of container <NUM> by the use of a chemical intermediary.

In a modification of the arrangement of <FIG> first non-expanding region <NUM> and second non-expanding region <NUM> can form part of a single non-expanding region.

In yet a further modification second non-expanding region <NUM> can be located in the temperature transition zone of the container and wherein minor expansion during the blow moulding step may take place.

In yet a further modification both first non-expanding region <NUM> and second non-expanding region <NUM> may be located in the temperature transition zone immediately below the locating ring <NUM> and, again, minor expansion of these regions may take place during blowing.

With respect to the last two variations described advantage is taken of the observation that expansion at the temperature transition zone can be limited by appropriate mould design and process control whereby unwanted distortion effects caused by the rigid interconnection of this temperature transition zone <NUM>, <NUM> via second rib <NUM> and rib connector <NUM> to ring <NUM> (or other non-expanding portion of the neck <NUM>) can be controlled.

In use preforms and containers blown therefrom can be manufactured as follows:
A preform is formed from orientable plastics material, preferably PET or like material in an injection moulding process. Slidable dies are illustrated in <FIG>, <FIG> and <FIG> and include a sliding core <NUM>, sliding blocks <NUM>, body <NUM>, base <NUM>, push block <NUM> and splits holder <NUM>. <FIG> illustrates the die in open position, <FIG> illustrates the die in closed position and <FIG> illustrates a side view showing accommodation of the stem <NUM>.

The completed preforms in a second and preferably separate step are subsequently passed to a stretch blow mould machine where the preforms are first reheated to the appropriate transition temperature (refer introduction). The non-expandable portion of the preform including locating ring <NUM> and stem <NUM> are shielded substantially from the reheat process by appropriate guarding. In most instances there is likely to be a temperature transition zone in the region <NUM>, <NUM> described with reference to <FIG>.

The reheated preform is then placed in a mould and biaxially stretched and the expandable portion blown to full size utilising processes known in the art. During this process the preform is supported at neck <NUM> and may also be supported at stem <NUM>. Stem <NUM> does not take part in the blow process although its stem end <NUM> may be partially enveloped by an external wall of the blown container.

<FIG> illustrates a modified two stage stretch blow mould machine <NUM> adapted to the stretch blow moulding (including biaxial orientation) of the preforms of previous embodiments and preforms of further embodiments to be described below with reference to later figures. These preforms have been previously injection moulded as described, possibly in a remote location from the present machine.

The machine <NUM> comprises a first carousel <NUM> adapted to receive integral handle preforms <NUM> from inclined chute <NUM> into apertures <NUM> spaced around the periphery thereof.

As first carousel <NUM> rotates it moves, via apertures <NUM> the preforms <NUM> from the chute <NUM> to a second carousel loading position where the preform <NUM> is transferred to a spindle <NUM> mounted near the periphery of second carousel <NUM>.

A sector of approximately <NUM>° of second carousel <NUM> is arranged as a preheating tunnel <NUM> where the preforms <NUM> are progressively heated by a heating bank mounted in opposed relationship to the path of travel of the preforms.

The suitably preheated preforms <NUM> are loaded consecutively into apertures <NUM> of a third carousel <NUM> which acts as a transfer mechanism to both suitably orient the preforms <NUM> about their longitudinal axis and present them to a mould cavity <NUM> comprising first half mould <NUM> and second half mould <NUM>.

It should be noted that during their time in the preheating tunnel <NUM> the preforms <NUM> are rotated about their longitudinal axis by spindles <NUM> and have a handle shield <NUM> mounted over the preform stem which subsequently forms a handle for blown container <NUM>. Details of the rotation of spindles <NUM> and the shielding of the preform stem are discussed more fully with reference to <FIG>, <FIG> and <FIG>.

Mould cavities <NUM> are mounted on the periphery of a fourth carousel <NUM>. During their travel through approximately a <NUM>° sector the half moulds <NUM>, <NUM> rotate to a closed position about their axis <NUM> and, whilst closed, the preform <NUM> enclosed therein is blown and biaxially stretched in known manner in order to produce an integral handle, blown container <NUM>. This container <NUM> is ejected as illustrated when the half moulds open preparatory to receiving a fresh, preheated preform <NUM>.

With reference to <FIG> further detail is shown of spindles <NUM> and handle shields <NUM> and their manner of operation upon and in relation to preforms <NUM> whilst passing through preheating tunnel <NUM> on second carousel <NUM>.

The spindles <NUM> are rotated by band drive <NUM> so as to, in one embodiment, rotate the preforms <NUM> through approximately four full axial rotations during their passage through the preheating tunnel <NUM>.

Whilst in the preheating tunnel <NUM> a handle shield <NUM> is lowered over the free end <NUM> of handle stem <NUM> so as to fully shield the handle stem <NUM> as best seen in greater detail in <FIG>.

The shield <NUM>, in one preferred form, is cylindrical save for a fluted open mouth <NUM> best seen in <FIG>. The fluted mouth <NUM> assists in ensuring maximal shielding of handle stem <NUM> and also assists in guiding the shield <NUM> onto the free end <NUM> of stem <NUM>.

Lifting and lowering of the shield <NUM> is effected through a shield support stem <NUM> which is suspended from a cam follower <NUM> adapted to travel on cam <NUM>.

The stems <NUM> are themselves rotated by band drive <NUM> so as to follow the rotation of spindles <NUM>. As best seen in end view of <FIG> the shield support stem <NUM> is offset from the cam follower stem <NUM> by virtue of being mounted near the periphery of platten <NUM>.

As cam follower <NUM> rides up cam <NUM> it pulls handle shield <NUM> up with it by virtue of the connecting link comprising shield support stem <NUM>, platten <NUM> and cam follower stem <NUM>.

Cam follower stem <NUM> can comprise a telescoped arrangement allowing relative axial rotation between two component, telescoping parts thereof.

The handle shield <NUM> can comprise alternative shapes other than cylindrical, for example an oval cross section is possible although the cylindrical arrangement having a circular cross section is preferred.

The handle shield <NUM> is preferably made of insulating material such as a ceramic material and is covered on an exterior surface <NUM>, in a preferred version, with a heat reflecting material which, ideally, is also light reflecting.

In use the reflective surface <NUM> causes light and heat emanating from heating bank <NUM> to be reflected thereof whereby two functions are performed. The first function involves protecting the handle stem <NUM> from heat. The second function is to reflect heat and light in the direction of that portion of the preform closest to the handle stem <NUM> so that it is evenly heated and tends not to be shadowed by the stem <NUM>.

In one particular form the handle shields <NUM> can be cooled by an air or nitrogen blast (not shown) directed at them whilst they are lifted clear of the preform <NUM>. This will assist to prevent radiated and/or convected heat building up within the cavity <NUM> of the shield <NUM>.

<FIG> illustrate details of a preform, mould and container blown therefrom and therein by the machine of <FIG>. With reference to <FIG>, in a preferred version, dimension A is greater than dimension B thereby to discourage tangling of preforms prior to loading into chute <NUM>.

It will be observed that the top end of the handle is located close to the locating ring in this version. It will also be noted that the stem of the preform which subsequently constitutes the handle of the blown container is fully supported within the half mould during the entire blowing process. In contrast the walls of the container including portions of the container wall peripherally opposite the top end of the handle stem are free to be blown within the constraints of the mould.

With reference to <FIG> a second version of a preform, mould and resulting blown container is illustrated wherein first non-expanding region <NUM> is relatively long in the axial direction including a portion <NUM> which extends from locating ring <NUM> down to and around at least a top portion of the connection of the handle stem <NUM> thereby forming a join of the top end of handle stem <NUM> to locating ring <NUM>. (Best seen in <FIG>).

In this version there is at least partial expansion of wall portions of the preform located peripherally away from the join of the handle stem <NUM> to the preform <NUM> (best seen in <FIG> and <FIG>). This expansion, relatively, is not as great as the biaxial expansion occurring below the first and second non-expanding regions <NUM>, <NUM>. It can, however, be significant in providing strength and resistance to gas permeation in at least second non-expanding region <NUM>, if not non-expanding region <NUM>.

With reference to <FIG> there is shown a container <NUM> incorporating an integral handle <NUM> which is biaxially blown from the preform <NUM> illustrated in <FIG> and <FIG>.

In this instance, as perhaps best seen in <FIG>, the blown container <NUM> includes a discontinuity region <NUM>. In this instance the discontinuity region <NUM> extends the entire circumference of the container <NUM>.

As best seen in <FIG> the discontinuity region <NUM> lies in a plane which subtends an acute angle alpha with a horizontal plane XX.

The plane of the discontinuity region <NUM> is oriented so that where it passes closest to the integral handle <NUM> it lies between first end <NUM> and second end <NUM> of the handle <NUM>.

In this instance that part of the discontinuity region <NUM> located furtherest from the handle <NUM> lies in the plane XX which passes through, or close to, join region <NUM> where the second end <NUM> of handle <NUM> is joined to container <NUM>.

The discontinuity region <NUM> is formed by a substantial change in direction of the wall of the container <NUM>, perhaps best seen in <FIG> wherein first tangent <NUM> to upper wall portion <NUM> intersects with second tangent <NUM> to lower wall portion <NUM> of container <NUM> at an obtuse angle beta, thereby forming a portion of the discontinuity region <NUM>.

This discontinuity region <NUM> imparts additional strength to the container walls, thereby to resist deformation of, particularly from internal pressures which can arise when the container is sealed, as for example when the container contains a carbonated beverage.

In order to assist in the creation of the discontinuity region <NUM> the preform <NUM> from which the container <NUM> is biaxially blown includes different wall thickness profiles, in this instance in the form of first wall profile <NUM>, second wall profile <NUM> and third wall profile <NUM> separated one from the other by first transition zone <NUM> and second transition zone <NUM> as best seen in <FIG>.

It will be observed that the wall thickness of third wall profile <NUM> is greater than the wall thickness of second wall profile <NUM> which, in turn, is greater than the wall thickness of first wall profile <NUM>.

The second end <NUM> of the handle <NUM> is joined to the container during a biaxial blowing operation by defamation and envelopment about the second end <NUM>. The second end <NUM> can include a bulbous portion including a bulbous portion of the types illustrated in <FIG>.

The preform <NUM> can be manufactured from PET materials in an injection moulding operation as described earlier in this specification. The preform <NUM> is then blown as a second stage operation in a stretch blow moulding machine so that its walls conform to the inside surfaces of a mould, also as described earlier in this specification.

With reference to <FIG> and <FIG> an alternative version of the container and the preform from which it is constructed are illustrated and comprises a rudimentary form of the multiple integral connection handle arrangement of the disclosure.

With reference to <FIG> the container <NUM> includes an integral handle <NUM> as previously described and constructed, save that the connection to the lower end of the container <NUM> is formed as an integral connection by way of a tag <NUM> which extends from a lower edge <NUM> of a wide part of the handle <NUM> down to a mid circumferential portion <NUM> of container <NUM> at which point it is integrally connected thereto. The lower edge <NUM> of the wide part of the handle <NUM> includes a landing portion <NUM> which merely rests on the surface of the container <NUM> at this point rather than being integrally connected thereto or otherwise connected thereto at this point.

A preform <NUM> from which the container <NUM> of <FIG> is blown is illustrated in <FIG>. This preform <NUM> is constructed substantially in the same manner as that illustrated in <FIG> except that lower edge <NUM> of handle <NUM> is integrally connected to the preform <NUM> by way of tag <NUM> in the manner illustrated in <FIG>.

The preform <NUM> is blown to form the container of <FIG> utilising the process previously described with reference to <FIG>, <FIG> and <FIG>.

With reference to <FIG> there is shown a preform <NUM> having a neck portion <NUM> and an expandable portion <NUM> located therebelow.

In substitution for the stem of the earlier examples in this specification is a loop <NUM> made from the same material as the wall <NUM> of the preform <NUM>. In this instance the loop <NUM> is integrally connected at a first end <NUM> to a first location <NUM> on and forming part of the wall <NUM>.

The other of the loop <NUM> being second end <NUM> is integrally connected into wall <NUM> at second location <NUM>.

The loop <NUM> is formed in the same mould as and at the same time as the preform <NUM> is moulded, in a preferred form from PET plastics material.

In this instance and with reference to <FIG> the loading of plastics material in the region of the wall <NUM> subtended between first location <NUM> and second location <NUM> can be differentially controlled as a function of location on the circumference of the wall <NUM> in this region designated the differential loading region <NUM> in <FIG>.

In this particular instance there is an increased loading of material in the region of <NUM> immediately between the first location <NUM> and second location <NUM> whilst, the opposite region <NUM> located diametrically opposite region <NUM> has material removed from it as indicated in dotted outline.

Differential material loading as a function of circumferential position on wall <NUM> aids in providing control over the wall thickness of the blown container <NUM> illustrated in <FIG>.

The container <NUM> can be blown in a two stage process utilizing the apparatus previously described in this specification and utilizing the shielding principals also described.

In this example the region <NUM> subtended between first location <NUM> and second location <NUM> remains substantially unchanged during the blowing process and can be considered an extension of and part of the next portion <NUM> of the preform <NUM>.

<FIG> illustrates an alternative form of construction of a loop <NUM> which, in this instance, again comprises an elongate, stem-like structure including reinforcing ribs <NUM> but having, in this instance, a deflectable portion <NUM> which is connected on one side by a first bridge portion <NUM> to the balance of the loop <NUM> and, at its other end by a second bridge portion <NUM> integrally to container wall <NUM>.

In this instance the second bridge portion <NUM> is akin in structure to the tag <NUM> previously described and provides a necessary element of flexibility. A first bridge portion <NUM> can be of the same kind of structure and, again, being integrally formed at the time that the preform is blown. In use, during a second stage blowing of the container <NUM> it will be observed that the container wall <NUM> to which second bridge portion <NUM> is integrally connected moves during blowing and this movement is accommodated by deflection of deflectable portion <NUM>, loop <NUM> about first bridge portion <NUM> and second bridge portion <NUM>.

In production, utilizing the apparatus previously described, it is possible to move material differentially within a wall portion such as, for example, in the differential loading region <NUM> it is possible to cause the material closest to the inside of the container to move whilst leaving the material closest to the outside of the container essentially static relative to first location <NUM> and second location <NUM>, thereby leaving the outside wall region stable during the second stage blowing step.

In production in a two stage machine it is important to have a heating tunnel of sufficient width to allow for rotation of the preforms with stem/loop protecting thereon. It is also important to have the ability to shield in a controllable manner the stem/loop portions of the preform during its pass through the heating tunnel and also the ability to selectively shield that region of the preform wall subtended between and beneath the stem/loop thereby to provide an important element of control over the heat profile throughout the preform immediately prior to its insertion into the mould cavity for the second stage blow moulding step.

In a particular form the heat shield can be attached to a mandrel and can pass into the mould cavity for retention therein during the second stage blowing step.

Whilst a single handle has been shown on embodiments described thus far it will be appreciated that more than one handle can be provided on a given container following the principals described in this specification.

A preform <NUM> according to a further embodiment of the disclosure is illustrated in side section view and, in this instance, includes a symmetrical thickening of the wall <NUM> of the preform <NUM> in the lower region <NUM> which extends from immediately below the point of connection <NUM> of the lower end <NUM> of handle <NUM>. In a second, intermediate region <NUM> located between point of connection <NUM> and point of connection <NUM> of handle <NUM> the wall thickening of the preform <NUM> tapers gradually from first thickness T1 to second (thinner) thickness T2.

This thickening is symmetrical about the longitudinal axis TT of preform <NUM> and results in a controllable increase in the thickness of material in blown container <NUM> (refer <FIG>) in the corresponding intermediate region <NUM>, but also in a sub-region <NUM> immediately below point of connection <NUM> of the lower end of handle <NUM>. It is postulated that the increased thickening of the blown container in the region <NUM> results from a flowing of the material from intermediate region <NUM> through to sub-region <NUM> during the second stage process of blow moulding, thereby to provide control over the wall thickness of material in the region <NUM> of the blown container <NUM>.

<FIG> provide alternative views of the blown container <NUM>. <FIG> illustrates more clearly the anti-symmetric bulbous portion <NUM> which is offset about the longitudinal axis TT with respect to handle <NUM>.

<FIG> illustrates a star formation indentation <NUM> in base portion <NUM> of container <NUM>. It comprises a central, circular indentation <NUM> from which subtend wedge shaped indentations <NUM> in a circular array as illustrated in both <FIG> and <FIG>.

In this instance container <NUM> also includes longitudinal indentations <NUM> in the walls of region <NUM> as illustrated in <FIG>, thereby to increase the strength of the blown wall portions in this region.

In accordance with a second series of preferred embodiments of the disclosure a stretch blow moulding machine <NUM> as illustrated in <FIG> is utilised to stretch blow mould a PET resin preform <NUM> as shown in <FIG> so as to produce an integral handle container <NUM> as illustrated in <FIG>. The preform <NUM> and resultant container <NUM> are of a type illustrated in and described in patent application to the same applicant <CIT>.

In one preferred form, a stretch blow moulding machine <NUM> of <FIG> includes a chain drive transport mechanism <NUM> which has a plurality of mandrels <NUM> mounted thereon at substantially equally spaced intervals, such that each mandrel follows a generally oval path through various processing stations on the machine <NUM>.

A preform <NUM> mounted on a mandrel <NUM> proceeds from loading station <NUM> to heating station <NUM> to stretch blow moulding station <NUM> and thence to unloading station <NUM>.

As illustrated in <FIG> through to <NUM> each mandrel <NUM> includes a nesting shield <NUM>, a perspective view of which is shown in <FIG>.

The nesting shield <NUM> is adapted to receive within it handle stem portion <NUM> of preform <NUM> for the purpose of shielding handle stem portion <NUM> against heat imparted by radiant heaters <NUM> as the preform is transported through the heating station <NUM> in the direction indicated by the arrow in <FIG>.

As the preforms <NUM> are transported through the heating station <NUM> they are rotated on mandrels <NUM> by second chain drive <NUM> acting on a toothed peripheral portion (not shown) of each mandrel <NUM>. Rotation of the mandrels <NUM> is effected by reason of the speed of rotation of chain transport drive mechanism <NUM> being different from the speed of rotation of second chain drive <NUM>.

At the time of entry into blow moulding station <NUM> each preform <NUM> is raised proud of top portion <NUM> of mandrel <NUM> in order to permit engagement of cavity portions of die halves <NUM> around base step portion <NUM> of handled step portion <NUM> and preform neck ring <NUM>.

It is to be noted that the die halves <NUM> include indentation <NUM> adapted to receive nesting shield <NUM> therewithin when the die halves <NUM> have come together thereby to house and protect the nesting shield <NUM> against damage during the blow moulding stage. During blow moulding the preform <NUM> is biaxially stretched by stretch rod <NUM> and the injection of gas (not shown) into the interior of the preform <NUM> whereby it conforms to the shape of the mould cavity to form container <NUM>.

The die halves <NUM> then open and chain drive transport mechanism <NUM>, temporarily stopped during the blow moulding process is caused to rotate again so as to present blown containers <NUM> at unloading station <NUM> for removal therefrom by forks <NUM>.

With reference to <FIG> there is shown a perspective view of a <NUM> cavity preform mould <NUM> adapted to be seated in an injection moulding machine (now shown) which injects PET <NUM> (or like orientable plastics material) through injection nozzles <NUM> (refer <FIG>) into preform shaped cavities <NUM> formed when the dye is in closed condition, as best seen in <FIG> and <FIG>. The dye cavity is then opened causing the splits <NUM>, <NUM> to be forced apart by cams <NUM> thereby permitting ejection of the handled preforms when sliding cause <NUM> are withdrawn, as best seen in <FIG>.

The injection stage typically takes between <NUM> seconds and one minute on a <NUM> tonne injection machine allowing the production of <NUM> preforms at one time during this time period.

In accordance with the modified two stage process the preforms <NUM>, after ejection, are allowed to cool and cure for at least <NUM> hours before placement in the blow moulding machine described and shown with reference to <FIG>. Ideally the preforms are allowed to cool to room temperature during this time and, most preferably, are allowed to cure for at least <NUM> hours prior to introduction to the blow moulding machine in order to ensure consistency of structure of the preforms and, hence, consistency of blowing in the critical second stage.

A typical production rate for the blow moulder described in <FIG> onwards is of the order of <NUM>-<NUM> blown containers per hour thus matching the production rate of the <NUM> cavity preform mould.

With reference to <FIG>, in a further example of a second stage <NUM> of a two-stage process, previously injection moulded preforms <NUM> proceed through the following stages:.

In line with the claimed invention, the body portion <NUM> of preforms <NUM> must be heated to the required degree of plasticity so that the material in the body <NUM> of the preform can be bi-axially oriented in the stretch-blow-moulding process. However, neither the neck portion <NUM> nor the handle <NUM>, should be subjected to bi-axial stretch blow moulding and must be shielded from excessive heat during the heating stage to prevent their crystallization with consequent loss of strength. Thus for transport through the heating stage <NUM>, the handle <NUM> of the preform <NUM> is protected by a shield <NUM>, and the neck portion <NUM> by a cylindrical socket <NUM>, as shown in <FIG>.

The orientation of the handle must be controlled at a point prior to the entry of the preform into the heating stage to enable the heat protective shield <NUM> to be correctly fitted over the handle <NUM> of a preform <NUM>. Furthermore, it is essential that each preform <NUM> is presented to the moulding tool <NUM> with the handle correctly oriented so that the handle is correctly enclosed in the halves of the mould when this closes for the blowing stage.

With reference to <FIG> and <FIG>, in one preferred form, preforms <NUM> are fed from a suitable supply source, such as for example a hopper or a vibratory bowl <NUM> to an infeed rail <NUM> at loading station <NUM>. Infeed rail <NUM> is arranged so that preforms <NUM> progress along rail <NUM>, either by gravity, vibration or other linear transporting means, supported between parallel rail elements <NUM> and <NUM> at the underside of locating ring <NUM>, as shown in <FIG>.

The orientation of the handles <NUM> of the preforms during transport along infeed rail <NUM>, is preferably controlled by a guiding channel (not shown) to loosely constrain the handles from assuming an orientation approaching, or at right angles to the direction of travel. Preforms <NUM> are thus constrained to proceed along infeed rail <NUM> either with the handle <NUM> pointing generally forward of the body <NUM> or trailing it. An escapement (not shown) at the end of infeed rail <NUM> provides for control of sequential discharge of individual preforms <NUM> from the end of the rail.

As shown in <FIG> and <FIG>, preforms thus released from infeed rail <NUM>, are allowed to drop vertically into an orienting apparatus <NUM> fixed directly below the end of infeed rail <NUM>. In a preferred form, the orienting apparatus <NUM> shown in <FIG> consists of a truncated cylindrical sleeve <NUM> which has an internal diameter adapted to allow free sliding passage of the cylindrical body <NUM> of the preform and locating ring <NUM>. The wall of the sleeve <NUM> is provided with a slit <NUM> extending the length of the sleeve <NUM> from a handle inlet opening <NUM> at the upper edge <NUM> of the sleeve <NUM>, to a handle outlet opening <NUM> at the lower edge <NUM>. The slit is of sufficient width to allow sliding passage of the handle <NUM> of a preform <NUM>.

The upper edges <NUM> and <NUM> of sleeve <NUM> are formed to guide a handle <NUM> into the slit <NUM>. For this purpose the upper edges <NUM> and <NUM> are formed to slope steeply from respective high points <NUM> and 744A diametrically opposite the handle inlet, down to the handle inlet opening <NUM> of slit <NUM>. To ensure that the handle does not fall onto and become lodged on the highest points on upper edges <NUM> and <NUM>, the infeed rail <NUM> is arranged approximately at right angles to the radial position of slit <NUM>. Thus handles <NUM> which, as described above are prevented from assuming this orientation while conducted along the infeed rail <NUM>, cannot contact the upper edges <NUM> and <NUM> at the highest points, but will rather drop onto the orienting device with the handle contacting either sloping upper edge <NUM> or <NUM>.

Sloping edges <NUM> and <NUM> slope down to respective sides of the slit <NUM>, from the highest points <NUM> and 744A, ending in respective smoothly rounded corners <NUM> and <NUM> at the handle inlet opening <NUM>. The slope is sufficient to ensure that the handle <NUM> of the preform <NUM> slides along the sloping edge sections.

A preform <NUM> falling into the apparatus <NUM> with a handle <NUM> not aligned with slit <NUM> will, as the handle makes contact with either sloping section <NUM> or <NUM>, be rotated as it slides down under its own weight, until handle <NUM> is aligned with slit <NUM> and the preform <NUM> falls cleanly through the apparatus.

<FIG> shows a section of the handle orientation and transfer to the heating stage of one preferred form of a blow moulding machine. As described above, a preform <NUM> is shown falling into the orienting apparatus <NUM>.

Arranged immediately below apparatus <NUM> is an indexing table <NUM> provided around its periphery with a number of equally spaced nests <NUM>, so situated that each successive nest <NUM> comes to an aligned position with the axis of apparatus <NUM> at each indexing of the table <NUM>. Nests <NUM> are adapted to receive a preform <NUM> and retain it in such a way that the orientation of the handle <NUM> initially imposed by apparatus <NUM> is maintained relative to each nest <NUM> for the duration of the preform's retention in the nest. (Note all the nests shown in <FIG> are empty.

When, with the indexing of the table <NUM>, a preform <NUM> reaches a transfer station <NUM>, the preform is ejected upwardly out of the nest <NUM> in which it was supported, to engage with one of a series of mandrels <NUM> of the preform transport system <NUM>, operating between the loading station <NUM> and the blow-moulding tool <NUM>. A preferred mandrel arrangement with a preform attached is shown in <FIG>.

When inserted into the mandrel, the open neck <NUM> of the preform <NUM> is pushed over a resilient plug <NUM> located in a cylindrical socket <NUM> at the base of the mandrel. The plug <NUM> enters the open neck as an interference fit sufficient for the weight of the preform <NUM> to be supported within the socket <NUM>. The socket also acts to shield the neck <NUM> from excessive heat during the heating stage.

The proper preparatory heating of a preform <NUM> is critical to the subsequent stretch blow moulding stage. The necessity to shield the handle <NUM> of the preforms complicates the correct distribution of the heat energy applied to the preform and requires careful design of the heat shield <NUM> and the arrangement of the heating elements.

<FIG> is a more detailed sectioned view of a preform <NUM> fitted with a heat shield <NUM>. The mandrel <NUM> and retaining means for supporting the preform are not shown in this view for clarity. It will be noticed that the shield <NUM> for the handle <NUM> of the preform <NUM> is carefully shaped to protect the handle <NUM> yet allow heat energy from the heating elements (shown in <FIG>) to reach that region <NUM> of the body <NUM> of the preform lying between the upper and lower attachment points <NUM> and <NUM> of the handle <NUM>. The heat shield <NUM> comprises side portions <NUM> (only one is visible in the sectioned view of <FIG>) extending substantially over opposing sides of the handle <NUM>. The side portions <NUM> extend from opposing edges of a spine element <NUM> which conforms to upper portions of the handle and which is attached to the mandrel socket <NUM>. The shield is open at the underside of the handle to allow for the preform and its handle to be driven upwardly to engage with the mandrel, and subsequently, at the end of the heating stage to be withdrawn from the shield.

To ensure the optimum heat distribution, the sides <NUM> of the heat shield <NUM> have been shaped to leave a gap <NUM> to allow heat penetration to region <NUM> as the preform is rotated during its transition through the heating stage. The size and shape of gap <NUM> are determined empirically in combination with the optimal arrangement of the heating elements <NUM> of the heating system as shown in <FIG>.

With reference to <FIG>, the heating system <NUM> comprises banks of heating elements <NUM> supported at their outer ends by adjustable racks <NUM> in a manner well known for preheating the preforms of conventional symmetrical containers.

In the present application however, the heating elements <NUM> are arranged in a pattern as shown in <FIG> and their individual intensity adjusted to take into account the handle and the particular energy density required to ensure that all parts of the preform are heated to the required degree of plasticity as the rotating preform <NUM> passes along the banks of heating elements.

In a first alternative preheating arrangement (not shown), a preform is again attached to a supporting mandrel for passing through a heating stage. In this arrangement however, each mandrel is provided with an elongate cartridge heater, coaxial with the rotation axis of the mandrel and body portion of the preform, and extending substantially the length of the body portion of the preform. The preform is thus heated from the inside. The cartridge may be divided along its length into several individually controllable heating segments so that heating may be adjusted to suit any wall thickness variations of the preform body.

In a second alternative preheating arrangement (not shown), each preform is enclosed by two halves of a heating shroud as the preform enters the heating stage. The shroud is linked to a separate transport system which drives the shroud in synchronous movement with that of the mandrels. At the emergence of the preform from the heating stage, the shroud opens and the preform continues to transit to the blow moulding tool. The shroud can be arranged to fit relatively closely to the body of the preform, leaving the integrally attached handle substantially outside the shroud and thus protected from the preheating of the preform.

To ensure even heating of the body <NUM>, the preforms <NUM> must also be rotated as they pass through the heating stage <NUM> past the banks of heating elements <NUM> shown in <FIG> and <FIG>. A necessary feature of the mechanism driving this rotation is that orientation of the handle at the end of the heating stage <NUM> must be such as to ensure that the handle correctly enters the blow moulding tool <NUM>. Two preferred arrangements for achieving this result are described.

Each mandrel <NUM> (shown in <FIG>) includes a mounting <NUM> for attachment to the transport system <NUM>. Transport system <NUM> may comprise a twin-strand chain conveyor supported at each end by pairs of sprockets, with the mandrels mounted at intervals between the chains. Bearings <NUM> within mounting <NUM>, allow rotation of the preform <NUM> and its handle protecting heat shield <NUM>.

A sprocket or toothed pulley <NUM> engages with a fixed rack or chain (not shown) of the transport system so as to induce rotation of the preform as it is carried past the heating stage <NUM>. This rack or chain is arranged along the lower leg of the twin-strand conveyor, this being the leg along which the mandrels are carrying preforms through the heating stage. To maintain the orientation of the mandrels both at the preform loading and unloading stages, the mandrels are provided with a guiding surface which slidingly engages with a fixed rail, preventing rotation. The rack is of a length and number or teeth, which together with the pitch diameter of the toothed pulley <NUM>, is designed to impart a whole number of rotations to the preforms so that the handle has the same orientation when leaving the end of the rack as it first had after insertion at the preform loading point.

The containers of the present disclosure may be successfully blow moulded in suitably modified conventional blow moulding machines. Typically the rotation of the preforms through the heating stage of these machines is not adapted to ensure that preforms have any particular orientation at the point where they enter the blow moulding tool. Preforms generally are supported on a mandrel carriage travelling along a recirculating rail system with a sprocket on the carriage engaging a chain or rack as the carriage passes the heating banks, thereby inducing the rotation of the preform. The sprocket, and hence the preform attached to the carriage mandrel, are freely rotating when not in contact with the rotation inducing system of the heating stage.

Typical also of conventional stretch blow moulding machines is that the transport rail, and the carriage and mandrel assembly pass through the blow moulding stage, the blown container only being ejected off the supporting mandrel when the container emerges from the moulding tool. The transport system moves incrementally, to allow the carriage (or carriages in the case of a multi-cavity tool) to remain stationary while in the moulding tool for the blowing cycle.

The present disclosure includes a means of controlling the orientation of the mandrels for moulding a container with integral handle on such a conventional machine. The arrangement controls the orientation of the mandrels both at the fitting of the preforms to the mandrels prior to entry to the heating stage and at the entry into, and transit through the moulding tool.

For this purpose each of the conventional carriages of a standard stretch blow moulding machine is modified or replaced with carriages fitted with a spring-loaded locking pawl for engaging with a notch provided on a boss of the carriage sprocket. The pawl is activated into potentially engaging the notch and thus locking the sprocket, by a lever projecting from the side of the carriage contacting a fixed cam or ramp mounted adjacent the transport rail.

This activation occurs at a point on the transport rail prior to the carriage and mandrel entering the moulding tool. At that point the sprocket is no longer in contact with the rotation driving system; that is the sprocket is free to rotate. At the following incremental stop of the transport system after activation of the pawl, an electrically driven friction wheel engages the sprocket, rotating it until the notch comes into alignment with the spring-loaded pawl. The pawl engages the notch, arresting the rotation of the sprocket. The mandrel is then correctly aligned for the mandrel and handle of the preform to enter the cavity of the blow moulding tool.

When the carriage emerges from the tool, the sprocket is still locked. The blown container is ejected from the mandrel and the carriage increments to the loading station to accept a pre-oriented preform as described above. Prior to the carriage re-entering the heating stage, the lever controlling the pawl is brought into contact with a second fixed cam or ramp, which reverses the position of the lever, withdrawing the pawl from the notch to allow the machines rotation system to control the rotation of the preform through the heating stage.

In the First Example described above, the preforms are ejected from the heating stage transport system mandrels onto a transfer system (not shown), which carries each preform into the blow moulding tool, retaining the orientation of the handle. In this arrangement the handle is nested in a separate cavity of the mould such as for example illustrated in <FIG>. The same transfer system, which may comprise a two-strand conveyor for example, also transfers the blown container (or containers) out of the moulding tool.

In the Second Example described above, in which the mandrels of a conventional but modified blow moulding machine, transit through the moulding tool with the preform, it is necessary to accommodate the heat shield in the mould tool. The heat shield shown in the example of <FIG> and <FIG>, is fixed relative to the mandrel and so the cavity for the handle must be sized to also accommodate the heat shield in its position covering the handle.

It is necessary however, that the upper and lower attachment points <NUM> and <NUM> of the handle <NUM> be closely confined in the moulding tool to prevent their movement during the stretching and blowing operation. The gaps between the body <NUM> and the heat shield <NUM> at the attachment points <NUM> and <NUM> are sufficient to shield these portions of the handle from excessive heat but still allow suitable structures in the moulding tool to engage and restrain the handle attachment points as the tool closes. A more preferable arrangement includes a mechanism (not shown) to lower the preform relative to the heat shield by an amount sufficient to expose the upper attachment point <NUM> of the handle through the larger gap <NUM> in the sides <NUM> of the shield <NUM>. With the lower attachment point <NUM> then located below the lower edge of the shield, this arrangement allows a better access of the restraining structures to confine the handle.

In an alternative arrangement (see for example <FIG>), the heat shield is not rigidly attached to the mandrel socket <NUM> but is hinged to it. In this arrangement a mechanism incorporated in the moulding tool rotates the heat shield away from the handle as the tool closes so that the handle is closely nested by the tool. The heat shield is then accommodated in its own cavity, separated from that of both the handle and the final body shape of the container.

It should be noted that although the region of the preform body defined by a narrow strip between the two attachment points <NUM> and <NUM> of handle <NUM> remains substantially stable during the stretching and blowing of the container, both the regions of the outer and inner surface layers laterally away from this narrow strip are subjected to biaxial stretching. Although the outer surface of the narrow strip remains substantially stable, the wall of the strip and the inner layers between the handle attachment points undergoes a degree of flow and thinning together with the surrounding regions as the plasticised material comes under the influence of the stretching and blowing forces.

It is important that those portions of the preform which are to be subjected to biaxial stretching and blowing, that is all of the body <NUM> below the neck or locating ring <NUM>, do not come into contact with the walls of the moulding cavity until forced to do so when the process of biaxial orientation of the material of the preform is substantially complete. For this reason the region between the two connection points <NUM> and <NUM> of the handle is not initially in contact with the wall of the cavity when the tool has closed on the preform. Rather there is provision of a slight gap between the outer surface of the preform body and wall of the cavity to ensure that no premature crystallization occurs (for example in a cooled tool) and that a degree of material flow and biaxial orientation, particularly of the inner layers of the region between the connection points does occur.

The above describes only some embodiments of the present invention and modifications obvious to those skilled in the art can be made thereto without departing from the scope of the present invention which is defined in the appended claims.

Claim 1:
A method for controlling a preform (<NUM>) for stretch blow moulding a container (<NUM>) with an integrally formed handle (<NUM>) and a neck portion (<NUM>);
said preform comprising a body portion (<NUM>) and said integrally formed handle;
said preform transferred from a preform supply source (<NUM>) to a blow moulding tool (<NUM>) for blowing said container (<NUM>);
said method including the steps of:
a. passing said preform through a preform handle orienting apparatus (<NUM>),
b. transferring said preform to a preform transportation system (<NUM>),
c. maintaining orientation of said integrally formed handle imposed by said preform handle orienting apparatus (<NUM>) during transfer to said preform transportation system (<NUM>),
d. rotating said preform during transport by said preform transportation system (<NUM>) past an array of preform heating elements (<NUM>),
e. heating the body portion of the preform to a degree of plasticity for the material of the body of the preform to be biaxially oriented in the stretch blow-moulding process,
f. shielding said integrally formed handle and neck portion from excessive exposure to heating from said heating elements (<NUM>) to prevent crystallization and consequent loss of strength of said integrally formed handle and neck portion, wherein for transport through a heating stage (<NUM>) the handle is protected by a shield (<NUM>) and the neck portion by a cylindrical socket (<NUM>),
g. transferring said preform from said transportation system (<NUM>) to said blow moulding tool (<NUM>), while maintaining orientation of said integrally formed handle.