AU686027B2

AU686027B2 - Handled plastic container

Info

Publication number: AU686027B2
Application number: AU38358/95A
Authority: AU
Inventors: Rolf Grob
Original assignee: ACI Operations Pty Ltd
Current assignee: Graham Packaging Pet Technologies Inc
Priority date: 1994-11-15
Filing date: 1995-11-14
Publication date: 1998-01-29
Anticipated expiration: 2015-11-14
Also published as: AU3835895A

Description

HANDLED PLASTIC CONTAINER

This invention relates to a handled plastic container in which the container is formed by blow moulding a preform and the handle is separately formed and then connected to the container during the container forming process.

Plastic containers for holding liquids including beverages and other domestic liquids are in wide spread use. During the 1980's plastic largely replaced glass as the material of first preference for the packaging of carbonated soft drinks. Plastics such as polyethylene terephthalate (PET) offer significant savings when compared with glass in packaging such products. Plastic is lighter than glass and plastic bottles are cheaper to make and cheaper to transport than glass bottles. In addition, there are clear safety advantages when using plastic given the inherent problems with breakages when using glass. Plastic containers are also in wide use for products such as detergents and fruit juices. Such products are generally packaged in one or two litre containers with relatively large outlet openings. For ease of pouring, containers such as those made from PVC often include a handle. In the past, the handle in plastic containers formed by extrusion blow moulding have been provided by blow moulding a hollow and integral handle portion into the container side wall. Given the constraints of container design, such handles are generally quite broad and often leave little room for one to firmly grasp the inside of the handle. Special moulds are required in the production of such bottles, they are more difficult to blow mould than a non handled bottle and there are difficulties with stress concentrations leading to possible container failure in the areas near the junction of the handle with the rest of the container.

In addition, it has not been generally possible to economically produce such handled bottles from synthetic polyesters such as PET. To extrusion blow mould PET it would be necessary to use a resin having a high intrinsic viscosity (i.e. well over 1.0). Such containers would not have the same degree of side wall orientation as a container stretch blow moulded from a preform. If an integral handle was formed in a PET container formed from a preform, special cutting tooling would be required to remove the flashing formed between the container side wall and the integrally formed handle due to the high orientation of th material.

An alternative is the use of a separate handle joined to the container. If separate handle is utilised it is possible to injection mould a handle which i narrower and thinner than the integral handles of the previously described blo moulded containers and if adequately attached to the container such handl designs are more effective and easier to use.

Various attempts have been made to attach separate handles to blo moulded containers formed from preforms but these have not been altogethe successful. One difficulty has been inadequate engagement of the handle wit the blow moulded container. A further difficulty has been the relative slowness o the processes used to produce such containers.

It is an object of the present invention to provide a method of securing separate handle to a plastic blow moulded container which enables relativel rapid manufacture and which leads to the production of a handled bottle wher the handle is firmly secured.

In accordance with the present invention, the applicants have developed modified preform having a moulded engagement portion adapted to engage wit part of a separately formed handle. In the past, it has been proposed that suc handles be connected to the plastic container by blow moulding the walls of th container around retaining portions provided at the respective ends of the handle For example, reference is made to Australian patent 637,696. The presen invention provides for engagement of at least part of the handle with a engagement portion which is preferably rigid and which is not subject to stretchin during the blow moulding process.

Thus, in accordance with one aspect of the present invention there i provided a method of manufacturing a handled plastic container which include the steps of:-

(a) positioning a preformed handle and a synthetic resin preform within a open blow mould without mutual engagement of said handle and preform said handle including upper retaining means and lower retaining mean and said preform including a moulded engagement portion adapted t engage with the upper retaining means of the handle; (b) causing the upper retaining means of the handle to interconnect with the engagement portion of the preform after the handle and preform have been separately positioned within the blow mould; and

(c) stretch blow moulding the preform in the blow mould wherein said blow moulding stretches the preform beneath the engagement portion into the blow mould to form a container and expands the side wall of the preform so to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform and so to secure and integrate the lower retaining means of the handle within the body of the formed container.

In another aspect of the invention there is provided a method of manufacturing a handled plastic container which includes the steps of: a) positioning a preformed handle and a synthetic resin preform within an open blow-mould without mutual engagement of said handle and preform; said handle having an upper retaining means in an upper portion of said handle and a free end and said preform including a moulded engagement portion adapted to engage with said upper retaining means of the handle; b) causing the upper retaining means to interconnect with the engagement portion of the preform after the handle and the preform have been separately positioned within the blow mould; and c) stretch blow moulding the preform in the blow mould wherein the said blow moulding stretches the preform beneath the engagement portion into the blow mould to form a container and expands the side wall of the preform so to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform.

The upper retaining means of the handle may be interconnected with the engagement portion of the preform either prior to or after the closing the blow mould. Preferably, the handle and preform are disposed within the open blow mould so that the upper retaining means of the handle is adjacent to but not interconnected with the engagement portion of the preform. The blow mould is thereafter closed and the preform pushed down so to effect engagement of the upper retaining means within the moulded engagement portion. Preferably the blow mould is shaped so to allow the preform to be moved downwardly from its original position within the blow mould by a distance of between about 1 to 4 mm so to enable interconnection of the preform with the handle. Conveniently, the preform is pushed down by the blow nozzle intended for use in introducing the high pressure gas into the preform to cause stretch blow moulding.

Preferably the handle and the preform can be positioned within the blow mould substantially simultaneously. In a most preferred embodiment the handle and preform are positioned in the mould by a single transfer arm which holds them both but where the handle and preform are not mutually engaged with each other. The handle may also be inserted into the blow mould marginally earlier or later than the preform and the side wall of the preform and the top of the handle may be respectively shaped so that the preform may slide across the top of the handle when being positioned adjacent to the handle in the blow mould. Preferably both the handle and preform are transferred into the blow mould in planes which are substantially parallel.

The upper retaining means and the moulded engagement portion may be of various shapes and configurations. Whatever the configuration, the engagement portion on the preform should resist vertical (upwards) or horizontal detachment of the upper retaining means once interconnected.

Preferably, the upper retaining means of the handle is a lug or protrusion disposed at or adjacent the end of the top of the handle. In such arrangement, the moulded engagement portion of the preform is preferably in the form of a flange located beneath a neck finish on the preform, the flange including a depending lip so to provide a downwardly facing groove into which the lug or protrusion at the end of the handle may be retained. Alternatively, the flange may include an aperture into which the lug may be inserted.

Some preforms used on the commercial stretch blow moulding of containers include a flange beneath the container neck finish. This flange (often referred to as the "support ledge") has many purposes including the mechanised transfer of the preform to and from a blow mould and the support of the preform within the blow mould during the introduction of high pressure gas to blow mould the container. Altemative arrangements of an appropriately shaped retaining means on the handle and a co-operating engagement portion on the preform will be self evident to persons skilled in the art. For example, it is possible to reverse the arrangements described above so that a downwardly facing lug is provided on the preform and an aperture or groove formed within an upper portion of the handle. Preferably, the upper retaining means of the plastic handle extends from a curved support surface shaped to follow the geometry of the preform immediately beneath the moulded engagement portion. Such a support surface assists in the positioning and location of the upper retaining means for proper engagement with the moulded engagement portion of the preform. Where a support surface is provided its inner diameter should match the outside diameter of the preform.

The arc length of the support ring may vary but it is found that it is easier to insert the handle into conventional blow moulding tools when the arc is relatively short.

In the embodiment of the invention where the handle includes a support surface which follows the geometry of the preform, it is particularly preferred that the handle also include a recessed portion adjacent to the support surface which comprises one or more ribs. In such arrangement, when the preform is blown, the portion of the preform immediately adjacent the support surface will expand into the recessed portion but less so in those areas comprising ribbing. As a consequence, once the bottle is blown the ribs in the recessed portion will be located within small indentations on the container and the ribs and indentations will thus co-operate to resist rotational movement of the handle.

The lower retaining means of the handle is preferably a lug or protrusion extending from the lower end of the handle. It should be shaped so that on blow moulding of the preform expansion of the side wall will capture and secure the lug within the formed body of the container. It may be of various geometrical shapes. Most preferably a lug which incorporates a hook or other extension is utilised so to encourage secure engagement with the body of the container.

The handle may be of any suitable configuration. In one embodiment of the invention, the container formed is blow moulded so to include a recess on one side suitable for accommodating the handle. Preferably, this recess includes a ledge onto which the bottom part of the handle may rest. In this configuration, it is preferred that the handle be generally "C" shaped in configuration with the upper and lower retaining means being at opposite ends. In a particularly preferred embodiment, the cross section of the handle is "IT shaped so to include terminal flanges and a connecting web. It is preferred that the terminal flanges face downwardly at the lower end of the handle so that a hollow is formed under the connecting web. In this embodiment, the lower retaining means may be a lug extending from the web. When configured in this way, the blow moulding of the preform in the vicinity of the lug forms a container side wall which fills the hollow formed by the flanges underneath the connecting web and thus securely retains the lug in position. The handle may also include reinforcing ribs. In the embodiment described above in which the handle has terminal flanges extending from a web so to create a hollow on the underside of the handle it is preferred to strengthen the terminal flanges with ribbing as this area is exposed to high forces exerted by the expanding side wall of the preform during the blow moulding process. Preferably, the handle is formed by injection moulding. It is not necessary that it be made from the same plastics material as the bottle and it may be formed from a plastic such as high density polyethylene, polypropylene, PET, recycled PET, glass reinforced PET and glass reinforced high density polyethylene. The handle could also be made from a metal such as aluminium. The bottle and the handle can be made from the same material and this is preferably PET or recycled PET. This would enhance recycling of the bottle.

In accordance with a further aspect of the present invention there is provided a preform suitable for use in the method hereinbefore described. In particular, such a preform includes a base, an elongate side wall portion and a neck; the said neck including a preformed finish and beneath said finish an outwardly extending flange; said flange including a moulded engagement portion adapted to engage with either an aperture or lug on a handle. Preferably, the engagement portion is in the form of a lip depending from the outer edge of the flange. The preform may be made from any stretch blow mouldable polymer. Preferably, it is formed from a PET homopolymer or copolymer (whether virgin or regrind), or a multilayer structure which may include layers consisting of one or more of PET, PEN, EVOH or other polymers used in multilayer technology. ln accordance with a further embodiment of the invention, there is provided a handled plastic container, said container comprising a blow moulded plastic bottle and a separate handle interconnected thereto wherein said handle comprises upper retaining means and lower retaining means and said bottle includes a moulded engagement portion which is interconnected with the upper retaining means of the handle and wherein the lower retaining means of the handle is secured and integrated into the side wall of the container.

In yet another aspect of the invention there is provided a handled plastic container, said container comprising a blow moulded plastic bottle and a separate handle having a free end and interconnected to said bottle at another end by upper retaining means, said upper retaining means including a lug or protrusion, and the bottle including a neck finish having an engagement portion co-operable with said lug or protrusion connecting said upper retaining means with said bottle.

Preferred embodiments of the invention are hereafter described with reference to the following drawings in which:-

Figure 1 is a fragmentary cross sectional representation of a preform used in the invention;

Figure 2 is a perspective view of a handle suitable for use with the preform shown in Figure 1; Figure 2a is an enlarged perspective view of the area marked Ila in Figure

2;

Figure 3 is an alternative handle design also suitable for use with the preform shown in Figure 1 ;

Figure 4 is a perspective view of the handle and preform shown in Figures 1 and 3 being placed within an open blow mould;

Figure 5 is a cross sectional view of the blow mould shown in Figure 4 with the preform and handle as initially positioned therein;

Figure 6 is a cross sectional view of the blow mould handle and preform once the blow mould has been closed and the top part of the handle has been interconnected with the preform; and

Figure 7 is a perspective view of a handled bottle made in accordance with the invention. Figure 8 is a side elevation of an alternative handle suitable for use in the present invention.

Figure 9 is a front elevation of the handle shown in Figure 8 as shown from the side which faces away from the bottle to which it may attach. In Figure 1 there is shown a preform generally designated by the numeral

1. It comprises a screw thread finish 2, an outlet opening 3, elongated side wall portion 4, a base 5 and a support ledge 6. It will be appreciated that the screw thread finish may be substituted by any other preformed finish known in the art. For example to accept a "clip-on" cap or an other suitable closure. The support ledge 6 includes a lip 7 which depends from the edge of flange 6 so to form a downwardly facing peripheral groove 8. The groove 8 and lip 7 together form the required engagement portion necessary in the present invention. The preform shown in Figure 1 is preferably injection moulded and preferably formed from PET or recycled PET. If the preform is being formed using regrind material, it is preferable to use a three or five multi layer preform which includes one or more regrind central layers with virgin material on either side as are known in the art. The configuration and composition of such multilayer preforms are well known to those skilled in the art.

In Figures 2 and 2a, there is shown a first embodiment of a handle suitable for use with the preform shown in Figure 1 to form a handled container. The handle has upstanding flanges 9 and 10 which extend from the top of the handle 11 to the bottom of the handle 12. The flanges are interconnected by a web 13 which is slightly concave in profile. Flanges 9 and 10 are provided with indentations 9a and 10a on either side of the handle towards the lower end. At the upper end 11, there is provided a curved support surface 12a and a lug 13a. Lug 13a is shaped so that it may be seated behind lip 7 in groove 8 of the preform shown in Figure 1. The support surface 12a has a radius of curvature the same as that as the outer wall 4 of the preform 1 in the portion 14 located immediately beneath flange 6. At the lower end 12 of the handle, there is provided lower retaining means being lug 15.

In Figure 3, there is shown an alternative handle 16. Handle 16 is substantially the same as the handle shown in Figure 2 except at the upper end where the handle includes a raised engagement portion 17 which extends from the top of the support surface 12a along its full length. A recessed area 18 is provided in the lower portion of the support surface 12a and the recessed portion comprises two ribs 19 and 20. The handle has a smooth profile 21 on one side so to allow both the preform 1 and the handle to move together into the blow mould in parallel planes.

In Figures 8 and 9, handle 111 has a protrusion 112 in the upper retaining end 117 of the handle and a lower retaining end 113 which includes a projection 114 and a rib 115 which are integrated into the side wall of the bottle when blown. Protrusion 112 is adapted to locate in peripheral groove 8 behind lip 7. Handle 111 has a main body 116 which extends between the upper retaining end 117 and the lower retaining end 113 and includes a plurality of ribs 118, 119 to facilitate easy handling by the user and to aid grip. The upper retaining end 117 includes recessed portions 120 on either side and an opening 121 which extends all the way through upper retaining end 117 from a support surface 122 to the rear part 123 of the upper retaining end 117.

The bottle of the invention is made in accordance with the following steps. First, the preformed plastic handle 16 is transferred to an open blow mould 22 by a transfer arm 23 as shown in Figure 4. The preform shown in Figure 1 is preheated in accordance with standard methodology. It is thereafter transferred to the blow mould 22 by transfer arm 24. The preform 1 and handle 16 are transferred into the blow mould substantially simultaneously. The handle fits within cavity 25 and the preform within cavity 26.

In another embodiment not shown a single transfer arm may transfer both the preform and the handle into the blow mould. In this embodiment, which is particularly suited to the type of handle shown in Figures 8 and 9, there may be provided a pin on the transfer arm which locates in opening 121 and jaws which press into recessed portions 120. The pin and jaws are located in a region below the part of the transfer arm which holds preform 1. As shown in Figure 5, preform 1 and handle 16 are located adjacent to one another but are not interconnected. Raised engagement portion 17 is positioned immediately below groove 8. The blow mould halves are thereafter closed and a blow nozzle 27 is moved down on to the preform 1. Upon closing of the mould halves recessed portions in the mould (not shown) may hold the handle and the transfer arm may be retracted. The stroke of the blow nozzle is sufficient to move the prefor down so that engagement portion 17 locates within groove 8 so to interconnec the preform and handle. Recess 26 includes a groove 28 which is deeper tha support ledge 6 so to facilitate the downward movement of preform 1. Figure illustrates preform 1 and handle 16 positioned within the blow mould afte interconnection.

Once the blow mould has been closed and the preform and handl interconnected, a gas is then introduced into the preform 1 so to stretch and blo the preform beneath flange 7 into the closed blow mould 21 to form the container In the blow moulding process, plastic undemeath the support surface 12 expand and this pushes the handle insert further up into the groove 8 thereby furthe securing the handle into position. This restricts up/down movement of the handle The plastic also expands around the sides of the support surface 12 and thi restricts the sideways movement of the handle once the container has bee blown. The sideways movement is further restricted by ribs 19 and 20 an corresponding indentations 19a and 20a.

The lower end 12 of handle 16, lug 15 becomes surrounded by plasti which expands upwardly to fill the recess formed between flanges 9 and 10 Retaining lug 15 surrounded by the plastic resists sideways or horizonta movement and this resistance of movement prevents retaining portion 16 fro being levered out of the groove 8.

The container so formed is shown in Figure 7. It is noted that the handl 16 is designed so that it fits within the overall width/depth of the bottle. Thi facilitates easy package and transport of the bottle in that the handle will no interfere with cartons and boxes.

The bottle shown in Figure 7 has a recess 29 which includes a ledge 30 o which the lower portion of handle 16 sits. The bottle preferably includes side wal ribbing 31 to strengthen the walls against crushing.

In use, the bottle of the present invention has significant advantages ove prior art arrangements. The dimensions of handle permit easy access for th user's hand. It is strengthened due to the "U" shaped cross section and this cros section also facilitates easy use of the handle as the groove thereformed in th top of the handle enables the user to place his thumb in the concave section enabling easy stabilisation of the bottle as it is lifted and poured.

Once liquid has been removed from the container, the container may be crushed at point 32 shown in Figure 7. This facilities easy removal of the handle from the bottle as a whole. This easy removal is useful in recycling. If the handle is formed from a different material to the bottle then contamination can be minimised and even if the handle is made from the same material as the bottle, then removal may be desirable as different processing is often required in recycling thicker and harder materials as would preferably be used in a handle as compared with the thin and flexible blown container.

Thus, the present invention provides a container which is easy to use, simple to dismantle after emptying for recycling and which can be readily manufactured from a preform on blow mould apparatus at a relatively rapid rate.

It will be appreciated that various modifications and additions may be made to the preform, the handle and the bottle as hereinbefore described without departing from the spirit and ambit of the present invention.

Claims

Claims.

1. A method of manufacturing a handled plastic container which includes the steps of a) positioning a preformed handle and a synthetic resin preform within an open blow mould without mutual engagement of said handle and preform; said handle including upper retaining means and lower retaining means and said preform including a moulded engagement portion adapted to engage with the upper retaining means of the handle; b) causing the upper retaining means of the handle to interconnect with the engagement portion of the preform after the handle and preform have been separately positioned within the blow mould; and c) stretch blow moulding the preform in the blow mould wherein said blow moulding stretches the preform beneath the engagement portion into the blow mould to form a container and expands the side wall of the preform so to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform.

2. A method of manufacturing a handled plastic container which includes the steps of: a) positioning a preformed handle and a synthetic resin preform within an open blow-mould without mutual engagement of said handle and preform; said handle having an upper retaining means in an upper portion of said handle and a free end and said preform including a moulded engagement portion adapted to engage with said upper retaining means of the handle; b) causing the upper retaining means to interconnect with the engagement portion of the preform after the handle and the preform have been separately positioned within the blow mould; and c) stretch blow moulding the preform in the blow mould wherein the said blow moulding stretches the preform beneath the engagement portion into the blow mould to form a container and expands the side wall of the preform so to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform.

3. A method according to either one of claims 1 or 2 wherein the handle and preform are initially disposed within the open blow mould so that the upper retaining means of the handle is adjacent to but not interconnected with the engagement portion of the preform.

4. A method according to claim 3 wherein the upper retaining means and the engagement portion of the preform are caused to interconnect by moving the preform towards the handle after the blow mould is closed.

5. A method according to claim 4 wherein the preform is moved towards the handle by a blow nozzle adapted for introducing gas into the perform for the blow moulding of the container.

6. A method according to claim 5 wherein the preform is moved towards the handle by a distance of between 1 and 4mm to interconnect the upper retaining means with the engagement portion of the preform.

7. A method according to any one of claims 1 to 6 wherein the handle and preform are positioned in the blow mould substantially simultaneously.

8. A method according to any one of claims 1 to 7 wherein the handle and preform are transferred into the blow mould along planes which are substantially parallel.

9. A preform for use in manufacturing a plastic container, said preform including: a) a base; b) an elongate side wall portion; and c) a neck including a preformed finish and beneath said finish an outwardly extending flange, said flange including an engagement portion adapted to engage with co-operating retaining means on a handle.

10. A preform according to claim 9 wherein said engagement portion consists of a lip depending from the flange downwardly towards said base so as to provide a downward facing groove into which said co-operating engagement means on the handle may locate.

11. A preform according to claim 9 wherein said engagement portion consists of an aperture in said flange into which cooperating means on the handle may locate.

12. A handled plastic container, said container comprising a blow moulded plastic bottle and a separate handle interconnected thereto wherein the handle includes upper retaining means and lower retaining means, said upper retaining means including a lug or protrusion, and the bottle including a neck finish having an engagement portion co-operable with said lug or protrusion connecting said upper retaining means with said bottle, and wherein the lower retaining means is integrated with a portion of a sidewall of the bottle.

13. A handled plastic container, said container comprising a blow moulded plastic bottle and a separate handle having a free end and interconnected to said bottle at another end by upper retaining means, said upper retaining means including a lug or protrusion, and the bottle including a neck finish having an engagement portion co-operable with said lug or protrusion connecting said upper retaining means with said bottle.

14. A handled plastic container according to claim 12 or 13 wherein said engagement portion consists of a flange located on said neck finish and includes a depending lip so as to provide a downwardly facing groove into which said lug or protrusion locates.

15. A handled plastic container according to claim 12 or 13 wherein said neck finish includes an aperture into which said lug or protrusion locates.

16. A handled plastic container according to any one of claims 12 to 15 wherein said handle includes in the region of said upper retaining means a curved support surface having therein a recessed portion into which the blown bottle partially projects.

17. A handled plastic container according to any one of claims 12 to 16 wherein said upper and/or lower retaining means include one or more ribs or grooves into which the blown bottle at least partially projects so as to reduce lateral movement of said handle relative to said bottle.

18. A handled plastic container made in accordance with the method of any one of claims 1 to 8.

19. A handled plastic container made using a preform in accordance with any one of claims 9 to 11.

20. A method according to claim 1 substantially as hereinbefore described.

21. A handled plastic container according to claim 12 substantially as hereinbefore described with reference to what is shown in any one of the drawings.