IES20040108A2

IES20040108A2 - Construction of container

Info

Publication number: IES20040108A2
Application number: IE20040108A
Authority: IE
Inventors: William Alec Milligan
Original assignee: Preton Ltd
Priority date: 2003-02-20
Filing date: 2004-02-20
Publication date: 2004-09-22
Also published as: IE20040109A1; GB2399559B; GB2399559A; GB0403895D0

Abstract

A blow moulded plastics container (1) has a body (5) and an upstanding bored neck (2) communicating with the interior of the body (5), the bored neck (2) has threads (6) on its exterior for reception of a tamperproof closure and an exterior ribbed portion (7) adjacent the container body (5) for engagement with a tear-off tamper-indicating strip on the closure. The ribbed portion (7) is spaced-apart from the container body (5) by a thin walled neck connector (10) supporting the neck (2) on the container body (5) and forming part of the neck (2). <Figure 1>

Description

Introduction The present invention relates to blow moulded plastics containers and in particular to blow moulded plastics containers of the type having tamperproof or tamper evident seals thereon. Blow moulding of large plastics containers is the desired and conventional way of manufacturing such plastics containers. This is particularly the case when the containers are large of the order of fifteen to twenty five litre capacity.

However, as packaging regulations become more stringent, it has become more important to provide tamper evident or tamperproof seals on such containers. This is particularly the case where the containers are used for storing hazardous materials or indeed liquids whose contents cannot be tampered with prior to eventual use. For example, with many food products, this is essential. > c.

At the same time, with the provision of closures on containers, where is provided a bore neck for having a threaded exterior for the reception of a closure, it was conventionally the practice to keep the length of the neck, that is to say, the distance the neck projects beyond the body of the container to a minimum as the longer the 0 neck, the more difficult it is to blow mould. Thus, when it became necessary to provide tamper evident seals on these containers, the neck was still kept to a minimum so that the threaded exterior necessary for reception of a tamper proof strip was moulded close to or right on the container body. This has in turn led to considerable difficulties because there was a considerable quantity of material on the container body which has made it very difficult to provide a neck which projects at right angles to the container body and thus, very often, the necks of these containers, after moulding, distort and are effectively useless. A further problem with the present construction of blow-moulded containers is that they take some considerable time to cool, that is to say "machine cooling" within the machine and then subsequent to 0 removal from the mould. The first cooling cycle obviously reduces machine input, while the second cooling cycle can pose certain handling problems.

While it does not appear important to reduce a cooling time of the order of 45 21630IES Preton CompleteSpec Untracked 28JanO4 Temp15 -— ........? OPEN TO PUBL’C INSPECTION i lira._7 ) UNDER SECTION 28 ANL RULE 23 j JNLN0..ASa5........... ΙΕ η 4 0 1 Ο 8 seconds or the like, it can be very important. Further, the maintenance of the straightness of the neck is vital because if the neck is in any way distorted or moves away from the vertical, then the tamper evident seal on the closure will not work fully. This is because the critical base of the neck onto which the tamper evident seal engages is a ratchet, which ratchet can sink or become distorted so the closure "bottoms out" before a full seal can be made, in extreme cases, no seal is made and the container would leak its contents if filled. Unfortunately, with the present constructions of container, very often, on removing the container from the mould, the neck is damaged and the container has to be discarded. Further, when the neck is sufficient to allow it to be used, the fact that it is off-line or lacks straightness tends to cause purchasers of the containers disquiet, even though the container may operate perfectly correctly and further, the tamper evident seal may similarly work correctly. However, perception by the customer can cause certain perfectly usable containers to be rejected.

The present invention is directed towards overcoming some of these problems.

Sta tern ents.of Invention According to the invention, there is provided a blow moulded plastics container of the type having a body and an upstanding bored neck communicating with the interior of the body, the bored neck having threads on its exterior for reception of a tamperproof closure and an exterior ribbed portion adjacent the container body for engagement with a tear-off tamper-indicating strip on the closure in which the ribbed portion is spaced-apart from the container body by a thin walled neck connector supporting the neck on the container body and forming part of the neck. The critical ribbed portion, onto which the tamper evident ratchet of the closure engages, is easier to cool as it is not in contact with the main body of the container. It has been found that by this simple arrangement, cooling time can be reduced by some seconds, both in production cooling, i.e. machine cycle time, and post-mould cooling. Any reduction in machine cycle time is particularly advantageous. In this way, there is now less material for cooling and the cooling of the material is much more uniform that heretofore. 21630IES Preton CompleteSpec Untracked 28JanO4 Tempi 5 IE 04 0 1 08 However, the main advantage of the invention is that now the neck and that portion of the container adjacent the neck cools much more uniformly than heretofore and the neck tends to remain straight and upright projecting perpendicular from the container. This reduces the number of containers that have to be rejected due to distortions during cooling or due to distortions on removal from the mould. However, the fact that the cooling time is reduced means that the throughput of the machines can be greatly increased.

In one embodiment of the invention, the capacity of the container is in excess of fifteen litres.

In one embodiment of the invention, the wall thickness of the neck connector is of substantially the same thickness as the thinnest wall portion of the rest of the neck. The advantage of this is that the neck connector will therefore cool nearly as rapidly as the thinnest portion of the neck. - J In another embodiment of the invention, the neck connector is of substantially the same wall thickness as that of the container body. This should mean that there will be relatively uniform cooling of the neck portion and that portion of the container adjacent it. This will ensure no distortion and thus the neck should lie upright.

In one embodiment of the invention, the ribbed portion has a top face substantially orthogonal to the neck and an inclined bottom face merging into the neck connector. One advantage that would not be immediately apparent is that because the ribbed portion is of a construction such that it is spaced-apart from the rest of the container, the depth of the ribbed portion and hence the amount of material used in it can be reduced as it is no longer necessary for the ribbed portion to accommodate problems that arose heretofore in cooling.

In one embodiment of the invention, the length of the neck connector between the ribbed portion and the container body exceeds the wall thickness of the neck connector. 21630IES Preton CompleteSpec Untracked 28JanO4 Temp15 In another embodiment of the invention, the length of the neck connector between the ribbed portion and the container body is of the order of the wall thickness of the neck connector.

In a still further embodiment, the length of the neck connector between the ribbed portion and the container body is greater than half the wall thickness of the neck connector. Various lengths of neck connector may be chosen, as long as it allows effectively the cooling of the ribbed portion to be independent of the cooling of the container where the neck meets it.

Ideally, these containers have wall thicknesses in excess of 2 mm.

Detailed Description of the Invenlion J The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a side view of portion of the top of a container incorporating a neck, Fig. 2 is a sectional view through the top of the container, and Fig. 3 is a side view of the container.

Referring to the drawings, there is provided a blow moulded container, indicated generally by the reference numeral 1, having a neck, indicated generally by the reference numeral 2, the neck having an internal bore 3 and mounted in a recess 4 in the container. The container 1 has a body 5 with a capacity in excess of 15 litres. The neck 2 has an interrupted thread 6 for reception of a closure (not shown) and a further tear-off strip receiving teeth, ratchet or ribbed portion, indicated generally by the reference numeral 7, comprising teeth 8 interrupted by gaps 9. A thin walled neck connector 10 forms part of the neck 2 and supports it on the container body 5. 21630IES Preton CompleteSpec Untracked 28JanO4 Temp15 ,E °4 0 1 0 8 It will be noted that the ribbed portion 7 has a top face 12 which is substantially orthogonal to the neck 2, and an inclined bottom face 13 merging into the neck connector 10.

In moulding, the neck connector 10 will cool in a uniform way. Further, the neck connector 10 being of that construction allows more rapid cooling of the ribbed portion 7. Thus, in moulding the cooling of the neck connector 10, because it is connected to the container body, is generally the most difficult portion to cool but, however, is now less critical. The neck connector 10 allows the ribbed portion 7 to be more rapidly cooled. The separation of the rib portion 7 from the container body 5 allows more rapid cooling because there is.no contact between the main body of the neck 2 and the container body 5. _ ' The neck 2 tends to lie straighter than heretofore and less containers need to be rejected.

Generally speaking, the wall thickness of the neck connector may be substantially the same thickness as the thinnest wall portion of the rest of the neck 2 or may be of substantially the same wall thickness as that on the container body. The length of the neck connector 10 between the ribbed portion 7 and the container body 5 may exceed the wall thickness of the neck connector 10, may be of the same order or indeed, may be, for example, greater than half the wall thickness. All that is required is to make sure that the ribbed portion 7is far enough away from the main container body 5 to ensure there is adequate cooling and no distortion of the neck.

These containers are usually for capacities of the order in excess of 15 litres and further generally have wall thicknesses in excess of 2 mm. They are thus relatively substantial containers.

In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa. 21630IES Preton CompleteSpec Untracked 28JanO4 Temp15 ΙΕ Μ Ο 1 0 8 The invention is not limited to the embodiment hereinbefore described but may be varied in construction and detail. 21630IES Preton CompleteSpec Untracked 28Jan04 Temp15 IE 04 0 f 08

Claims

1. .A blow moulded plastics container having a capacity in excess of 15 litres of the type having a body and an upstanding bored neck communicating with the interior of the body, the bored neck having threads on its exterior for reception of a tamperproof closure and an exterior ribbed portion adjacent the container body for engagement with a tear-off tamper-indicating strip on the closure in which the ribbed portion is spaced-apart from the container body by a thin walled neck connector supporting the neck on the container body and forming part of the neck, the wall thickness of the neck connector being substantially the same wall thickness as that of the container body.

2. A blow moulded container as claimed in claim 1, in which the ribbed portion has a top face substantially orthogonal to the neck and an inclined bottom face merging into the neck connector.

3. A blow moulded container as claimed in claim 1 or 2, in which the length of 'the neck connector between the ribbed portion and the container body exceeds the wall thickness of the neck connector.

4. A blow moulded container as claimed in any preceding claim, in which the wall thickness of the container body exceeds 2.0 mm.

5. A blow moulded container substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. 21630IES Preton CompleteSpec Untracked 28JanO4 Temp15