GB2399559A

GB2399559A - Blow moulded container

Info

Publication number: GB2399559A
Application number: GB0403895A
Authority: GB
Inventors: William Alec Milligan
Original assignee: Preton Ltd
Current assignee: Preton Ltd
Priority date: 2003-02-20
Filing date: 2004-02-20
Publication date: 2004-09-22
Anticipated expiration: 2024-02-20
Also published as: GB2399559B; IES20040108A2; GB0403895D0; IE20040109A1

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).

Description

Introductlon The present invention relates to blow moulded plastics

containers and in particular to blow rnoulded 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,uarlicularly 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.

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 Q minimum fits the longer the 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 light axles 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 containcro is that they take some conshlerlle time to cool, that is to say "machine cooling" within the machine and then subsequent to removal from the mould. The first cooling cycle obulously 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 21 6301ES Proton CompleteSpeo 25JanO4 Temp1 5UNTRACKED

- -

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 "bultoms our' before a full seal can be made. In extreme cases, no seal is made and I the container would leak its contents if filled. Unfortunately, with the present constructions of container, very onen, on removing the container from the mould, du 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 try 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.

Statements of Induration

2 0 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 2 5 spaced-apart from the container body by a thin walled neck connector supporting the: neck on tile container Trudy and forming part of the neck. -I-ne critical ribbed portion, onto which the tamper evident ratchet of the closure engages, is easier to cool as it is not in conta:t with the main body of the container. It has boon found that by this i simple arrangement, cooling time can be reduced by some seconds, both in i 3 0 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 loss material for cooling and the cooling of the material is much more uniform that heretofore. I 21 6301ES Pretoe CompleteSpec 28JanO4 Temp15UNTRACKEC 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 I 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 excel 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. i In another embodiment of the invention, the neck connector is of substantially the i same wall thickness as that of tho container body. This should mea', U,al ll're will be relatively unrform cooling of the neck portion and that portion of the container adjacent rt. 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 noocooary for the ribbed portion to accomuadale 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.

21 6301ES Proton CompleteSpec 28JanO4 Tempt 5UNTRACKEC) - 4 - 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 [it' 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.

DP,taii DescUp of tile Invention 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: 2 0 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.

3 0 The neck 2 has an interrupted thread 6 freer 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 g. A thin walled neck connector 10 forms part of the neck 2 and supports It on the container body 5.

21 63OIES Preton ComploteSpac 2BJanO4 Temp1 5UNTRACKED - is - 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 t O. In moulding, the neck connector 10 will cool in a uniform way. Further, the neck connector 1U being or that construction allows more rapid cooling of the ribbed portion 7. Thus, in mouiding the cooling of the neck connector 1Q, 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 or ale 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 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 slave wall thicknesses In excess of 2 mm. They are thus relatively substantial containers.

In the specification the terms "comprise, comprises, comprised and comprising" or 3 0 any variation thereof and the terms Uinciude, 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.

216301 ES P reron CompleteSpec 28Jar'04 Tempt SUNTRACKED - 6 - The invention is not limited to the embodiment hereinbefore described but may be varied in construction and detail.

21 630tES Preton CompleteSpec 26JanG4 Ternp15UNTRACKED - 7 -

Claims

CL

1. 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 tampsrproof 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.

2. A blow moulded container as claimed in claim 1, in which the capacity of the container is in excess of fifteen litres.

3. A blow moulded container as claimed in claim 1 or 2, in which the wall 1 b thickness of the neck connector is of substantially the same thickness as the thinnest wall portion of the rest of the neck.

4. A blow moulded container as claimed in claim 1 or 2, in which the neck connecter is of substantially the same wall thicknecú ac that of the container 2 0 body.

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

6. A blow moulded container as claimed in any preceding claim, in which the length of the neck connector between the ribbed portion and the container body exceeds the wall thickncoa of the neck connector.

7. A blow moulded connector as claimed in any of claims 1 to 5, in which 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.

21 6301ES Preton CompleteSpec 28JanO4 Tamp1 SUNTR 4CKED -

8 - 8. A blow moulded container as claimed in any preceding claim, in which the length of the neck connector between the ribbed portion and the container I body is greater than half the wall thickness of the neck connector.

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

10. A blow moulded container substantially as berelubefore described With reference to and as illustrated in the accompanying drawings.

r.b - o loolple,aro-u4 Neon 216301ES Preton CompleteSpoo 28JanO4 Ternp15Ut4TRACKED