MOULDING OF PLASTIC CONTAINERS WITH HANDLES

Abstract

The production of a container with an integrated handle, by injection moulding a preform with an incorporated handle protrusion, where such protrusion has a direction perpendicular to the axis of the preform and then stretch blow moulding the said preform into a container, where before the end of the blowing step the handle protrusion is deformed into the shape and/or position it will have in the finished container.

Claims

1. A preform for blow moulding a plastics container, wherein said preform comprises a body area, a neck area, and at least one incorporated deformable handle protrusion, wherein a first end of the handle protrusion is connected on or adjacent to the neck area of the preform comprising a connection point and a second opposed, free end of the handle protrusion(s) extends outwardly away from the neck such that in an initial position the handle protrusion extends in a direction extending substantially perpendicular to the longitudinal axis of the body area of the preform, and wherein the second opposed, free end of the handle protrusion(s) comprises a structural feature that enables a secure engagement of the second opposed, free end of the protrusion to the blown body of the container, and wherein said preform is stretch blow moulded into a container and wherein the handle protrusion(s) is deformable around the connection point into a final predetermined position substantially parallel to or at an acute angle to the longitudinal axis of the body area of the container before the end of the blowing step.

2. The preform of claim 1, wherein said handle protrusion(s) is made from the same material as the preform and produced as an integral member with the preform during injection moulding of the preform.

3. The preform of claim 2, in which the handle protrusion(s) and preform are composed of PET.

4. The preform of claim 1, wherein said handle protrusion(s) is substantially linear in shape, and relatively thin so that it possesses sufficient flexibility in order for it to be deformed from an initial position to a predetermined final position during formation of the container.

5. The preform of claim 1, wherein said handle protrusion(s) is rigid for higher strength, and wherein flexing is possible at the connection point between the handle and the neck area of the preform, said flexing is achieved by the presence of a small thin area, wherein said thin area can flex to act as a pivot around which the handle will be rotated, to take its final position as it will be in the container.

6. The preform of claim 1, in which the structural feature extends at an angle from 90 degrees to 30 degrees relative to the longitudinal axis of the handle.

7. The preform of claim 1, comprising two handle protrusions on opposite sides of their neck area, wherein both of said handle protrusions are deformable so that they can be encapsulated by the blown body of the container so that the container produced will have two handles.

8. The preform of claim 1, wherein the handle comprises a region of increased thickness, at a point between the connection between the handle and the neck area of the preform, and wherein the region of increased thickness retains heat from injection moulding prior to blow moulding such that the region of increased thickness acts as a pivot point around which the handle will be rotated to take its final position as it will be in the container.

9. A method for producing a container with at least one integrated handle, the method comprising the steps of: injection moulding a preform as claimed in claim 1; and stretch blow moulding of the preform into the container, comprising placing the preform within a blow mould at a predetermined temperature; and stretching and blowing the preform inside the blow mould into a container such that the second opposed, free end of the handle protrusion is encapsulated by the blown body of the container; wherein at any time between preform moulding and the end of stretch blow moulding, the handle protrusion on the preform is bent or deformed from its initial position to a predetermined shape and position to form the finished container.

10. The method according to claim 9 wherein preforms are transferred for blow moulding while sufficiently warm such that sufficient heat is retained in an area of increased thickness of the section of the handle protrusion, said area in its warm state being the point of weakness thus enabling the handle protrusion to deform easily at that point.

11. An apparatus for the production of plastic containers with integrated handles, in which the apparatus comprises: injection moulding apparatus for preforms with incorporated handle protrusions as claimed in claim 1; temperature control apparatus arranged in use to adjust preform temperature and/or to re-heat preforms to stretch-blowing temperature; apparatus arranged in use to place preforms in the blow moulds. apparatus for deforming the handle protrusion of the preform into the predetermined shape and orientation of the container; and apparatus for stretching and blowing the preform inside the blow mould into a container, in a manner that the second opposed, free end of the handle protrusion is encapsulated by the blown body of the container.

12. A blow mould for enabling the production of bottles from a preform with at least one incorporated handle protrusions as claimed in claim 1, wherein said handle protrusion(s) are deformed before the final stages of blow moulding, said mould comprising at least one handle deforming mechanism.

13. The blow mould of claim 12 wherein said handle deforming mechanism is partially or wholly incorporated in the blow mould.

14. The blow mould according to claim 12 wherein said handle deforming mechanism is partially or wholly independent from the blow mould.

15. The blow mould of claim 12 comprising guides that guide the deformed handle from an initial position into its final predetermined position for encapsulation in the blown body of the container.

16. The blow mould of claim 15 further comprising a hold mechanism that holds the deformed handle in its final predetermined position, and accurately securing said handle(s) for encapsulation in the blown body of the container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The invention can be performed in various ways and, by way of example only, specific embodiments thereof will now be described, reference being made to the accompanying drawings.

[0036] FIGS. 1a to 1c illustrate the design of a bottle according to a first embodiment of the present invention in which the bottle comprises an integrated handle protrusion and the corresponding preform from which the bottle can be stretch blow moulded;

[0037] FIG. 2 illustrates the design of a bottle according to a second embodiment of the present invention in which the bottle comprises an alternative, stronger integrated handle and the corresponding preform from which the bottle can be stretch blow moulded;

[0038] FIGS. 3a and 3b illustrate two alternative embodiments of the method of the present invention for deforming a rigid handle on a preform from an initial position into a predetermined final position before blow moulding;

[0039] FIGS. 4a and 4b illustrate a number of different shapes and orientations that the handle protrusions can be bent and/or deformed to, adopting to various container designs; and

[0040] FIG. 5 illustrates a design of a bottle according to a further embodiment of the present invention and demonstrates the deformation of a handle portion during formation of the bottle.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0041] In the arrangements described below a container consists of a neck area 1, a body 2 and a handle 3. The corresponding preform has a neck area 1a, which is identical to the neck area 1 of the container, as this area is not affected by the stretch-blowing of the preform into the container. The preform also has its main body 4 and a handle portion 5 protruding outwards from its neck area 1a.

[0042] One such preferred arrangement is illustrated in FIG. 1, in which FIG. 1a illustrates in side view the overall shape of a container with the incorporated handle 3, FIG. 1b illustrates in isometric view the same container and FIG. 1c illustrates in isometric view the preform that can be used to produce this container, with the integrated handle protrusion 5.

[0043] Another preferred arrangement is illustrated in FIG. 2, in which FIG. 2a illustrates in side view the overall shape of a container with a rigid, stronger incorporated handle 3. FIG. 2b illustrates in isometric view the same container and FIG. 2c illustrates in isometric view the preform that can be used to produce this container, with the rigid, stronger integrated handle protrusion 5.

[0044] FIG. 3 illustrates two alternative designs of a preform with a rigid, strong handle, each alternative being suitable for a different way in which the bending or deformation of the handle to its final position in the blow mould can occur. In FIG. 3a there is a thin area 6, where the handle portion 5 is connected to the neck area 1a of the preform, placed at the place where the handle portion 5 should pivot when deformed to its final blowing position. Being a thin area 6, it is the weakest mechanically and will deform when a force is applied to move the handle portion 5, acting as a pivot around which the handle portion 5 will rotate. In FIG. 3b there is a thick area 7, where the handle portion 5 is connected to the neck area 1a of the preform, placed at the place where the handle portion 5 should pivot when moved to its blowing position. Being a thick area, in the cases where the preform is removed still hot from the injection mould so that it can be taken directly (or via a temperature adjustment step) to the blow mould for stretch-blowing, this thick area retains more heat and is therefore hotter and softer, so it is the weakest point and will deform when a force is applied to move the handle portion 5, acting as a pivot around which the handle portion 5 will rotate.

[0045] FIG. 4 illustrates the way in which the handle portions 5, as moulded on the preforms, can be deformed or bent, in order to take the final shape and position required, depending on the design of the container to be produced. FIG. 4a illustrates possible deformations 8 of a handle portion 5 similar to the one in FIG. 1, where this handle portion 5 is relatively thin and flexible so that it can be bent into shape by one or more deforming mechanism(s). The final shape and position of such a handle 3 can be determined mainly by the deforming mechanism(s) as well as by the design of the handle portion 5 as moulded on the preform and each handle position will also require a different container design for encapsulating the end of the handle portion 5. This invention provides for the flexibility of handle design in size, shape and orientation, allowing a big variety of possible bottle designs.

[0046] FIG. 4b illustrates possible deformations 9 of a handle portion 5 similar to the one in FIG. 2, where this handle portion 5 is rigid and strong and cannot be deformed in the way similar to the handle portion 5 of FIG. 4a. Instead this rigid handle portion 5 can be rotated about a pivoting point by the deforming mechanism(s), to any angle that is required by the design of the container, allowing flexibility in size, shape and orientation of the handle. Such a pivoting point can operate as described in FIG. 3.

[0047] The handle protrusions incorporated on the preforms, may be designed with features that make it easier for the deforming mechanism(s) to deform them reliably and/or features that help in the possible guiding and holding the handle protrusions securely in place during blowing and/or features that allow for a secure encapsulation of the end of the handle into the body of the container by the body wrapping around such features for preventing possible removal of the handle end from the container body.