GB2538051A

GB2538051A - A mould

Info

Publication number: GB2538051A
Application number: GB1507145.9A
Authority: GB
Inventors: John Michael Jurkiw Anthony
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-27
Filing date: 2015-04-27
Publication date: 2016-11-09
Also published as: GB201507145D0

Abstract

A mould (2, fig 1) for producing injection moulded in-mould labelled plastic containers is provided. The mould comprises: a rim moulding portion (12, fig 1) for use in moulding at least part of a rim of a plastic container; core part 10 includes a surface 14, for use in moulding a wall of the plastic container, having first and second elongate protrusions 21, 22 defining a major channel 31 therebetween; and at least one flow restricting protrusion 41, located in or for location in an interface region of the major channel and the rim moulding portion, for dividing the major channel into a multiplicity of minor channels in the interface region and for restricting the flow of plastic towards the rim moulding portion. The first and second elongate protrusions may be shaped, in the interface region, to cause plastic flowing in the interface region to spread across a greater distance in the interface region than the width of the major channel. When the plastic travels along the wall portion (7, fig 1) of the cavity (11, fig 1), the label (6, fig 1) adheres to the molten plastic and, when the plastic cools and solidifies, the label becomes integrated into the wall of the plastic container as it is formed.

Description

TITLE

A Mould

TECHNOLOGICAL FIELD

Embodiments of the present invention relate to a mould. In particular, they relate to a mould for producing injection moulded in-mould labelled plastic containers.

BACKGROUND

A mould for producing injection moulded in-mould labelled plastic containers may comprise a core part and an outer part. A label may be inserted into a cavity between the core part and the outer part prior to the injection of plastic into the cavity. When molten plastic is injected into the cavity, it forms a plastic container in which the label is integrated into a wall of the plastic container.

BRIEF SUMMARY

According to various, but not necessarily all, embodiments of the invention there is provided a mould for producing injection moulded in-mould labelled plastic containers, comprising a rim moulding portion for use in moulding at least part of a rim of a plastic container; a surface, for use in moulding a wall of the plastic container, having first and second elongate protrusions defining a major channel therebetween; and at least one flow restricting protrusion, located in or for location in an interface region between the major channel and the rim moulding portion, for dividing the major channel into a multiplicity of minor channels in the interface region and for restricting the flow of plastic towards the rim moulding portion.

According to various, but not necessarily all, embodiments of the invention there is provided a mould for producing injection moulded in-mould labelled plastic containers, comprising: a rim moulding portion for moulding at least part of a rim of a plastic container; a surface, for use in moulding a wall of the plastic container, having first and second elongate protrusions defining a channel therebetween; and flow restricting means, located in or for location in an interface region between the channel and the rim moulding portion, for restricting the flow of plastic towards the rim moulding portion.

According to various, but not necessarily all, embodiments of the invention there is provided a mould for producing injection moulded in-mould labelled plastic containers, comprising: a rim moulding portion for moulding at least part of a rim of a plastic container; a surface comprising a channel, having a width for channelling the flow of plastic towards the rim moulding portion; and spreading means for spreading plastic, flowing in the channel towards the rim moulding portion, across a larger distance than the width of the channel in an interface region between the channel and the rim moulding portion.

According to various, but not necessarily all, embodiments of the invention there is provided examples as claimed in the appended claims.

BRIEF DESCRIPTION

For a better understanding of various examples described in the detailed description, reference will now be made by way of example only to the accompanying drawings in which: Fig. 1 illustrates a schematic of a mould which is used to form an in-mould labelled plastic container using an injection moulding process; Fig. 2 illustrates a portion of a core part of the mould; Fig. 3 illustrates a close up of a portion of the core part of the mould; and Fig. 4 illustrates a portion of an in-mould labelled plastic container formed using the mould.

DETAILED DESCRIPTION

Fig. 1 illustrates a mould 2 being used to produce an in-mould labelled plastic container using an injection moulding process. In the illustrated example, the mould 2 is for producing generally cylindrical hollow containers with a rim.

The mould comprises a core part 10 and an outer part 4. A cavity 11 is present between the core part 10 and the outer part 4 which has a shape corresponding with the shape of the plastic container to be formed. The portion of the cavity 11 labelled with the reference numeral 5 is used to form the base of the plastic container. The portion of the cavity 11 labelled with the reference numeral 7 is used to form a wall of the plastic container. The wall may have any cross section including, for example, a circular, square, oval or octagonal cross section.

The mould 2 comprises a rim moulding portion 12 which is formed by a portion of the rim 12a of the core part 10 of the mould 2 and a portion 12b of the outer part 4 of the mould 2. The rim moulding portion 12 of the mould 2 defines the portion of the cavity 11 labelled with the reference numeral 9, which is used to form the rim of the plastic container. In the illustrated example, the rim 12a of the core part 10 of the mould 2 is used to form an upper surface of the rim of the plastic container and the portion 12b of the outer part 4 is used to form the outer and lower surfaces of the rim of the plastic container.

It can be seen in Fig. 1 that the wall portion 7 of the cavity 11 connects the base portion 5 of the cavity 11 with the rim portion 9 of the cavity 11.

Prior to molten plastic being injected into the mould 2, a label 6 is positioned between the core part 10 and the outer part 4 in the portion 7 of the cavity 11 that is used to form the wall of the plastic container.

The arrow labelled with the reference numeral 3 schematically illustrates molten plastic being injected into the cavity 11 of the mould 2. The arrows labelled with the reference numeral 8 illustrate injected molten plastic travelling through the cavity 11 of the mould 2. The injected molten plastic enters the base portion 5 of the cavity 11 before travelling down the wall portion 7 of the cavity 11. Eventually, the molten plastic reaches the rim portion 9 of the cavity 11. Once the molten plastic has cooled and solidified, a plastic container is formed.

When the plastic travels along the wall portion 7 of the cavity 11, the label 6 adheres to the molten plastic and, when the plastic cools and solidifies, the label 6 becomes integrated into the wall of the plastic container as it is formed.

If the flowing molten plastic does not travel to the rim portion 9 in a relatively uniform manner, the flowing molten plastic may cause the label 6 to move during formation of the plastic container and result in a poor quality plastic container being formed.

Fig. 2 illustrates a front elevation of the core part 10 of the mould 2 above the line labelled X-X in Fig. 1. In the illustration, the core part 10 of the mould 2 has been inverted, so the upper region of the core part 10 illustrated in Fig. 1 is the lower region of the core part 10 illustrated in Fig. 2. Similarly, the lower region of the core part 10 illustrated in Fig. 1 is the upper region of the core part 10 illustrated in Fig. 2.

As explained above, in the illustrated example, the mould 2 is for producing hollow plastic containers with a rim. As mentioned above, the container may have A circular, square, oval or octagonal cross section and the core part 10 of the mould 2 has a corresponding cross sectional shape.

The core part 10 comprises a curved outer surface 14 for use in moulding the wall of a plastic container. The surface 14 comprises a plurality of elongate protrusions 21-28 which extend along a length of the surface 14. The elongate protrusions 21-28 define a plurality of major channels 31-37 which also extend along the length of the surface 14. Each major channel 31-37 is positioned between a pair of elongate protrusions 21-28.

Fig. 2 illustrates first, second, third, fourth, fifth, sixth, seventh and eighth elongate protrusions 21-28 and first, second, third, fourth, fifth, sixth and seventh major channels 31-37. More elongate protrusions and major channels may be present on the portion of the surface 14 of the core part 10 that is not visible in Fig. 2.

Each elongate protrusion 21-28 has the same shape in the illustrated embodiment, although this need not be the case in every embodiment. Each elongate protrusion extends along a length of the surface 14 of the core part 10. Two adjacent elongate protrusions define a major channel 31-37 therebetween. For example, the first and second elongate protrusions 21, 22 define a first major channel 31 therebetween. The second and third elongate protrusions 22, 23 define a second major channel 32 therebetween, and so on.

An "interface region" is present between the exits of the major channels 31-37 and the rim moulding portion 12 of the mould 2. This is the region where, in use, molten plastic exits the major channels 31-37 and flows to the rim moulding portion 12.

The core part 10 also comprises a plurality of flow restricting protrusions 4147 in the interface region. First, second, third, fourth, fifth, sixth and seventh flow restricting protrusions 41-47 are visible in Fig. 2. Others may be present on the portion of the surface 14 of the core part 10 that is not visible in Fig. 2.

Each of the flow restriction protrusions 41-47 is positioned on the surface 14 of the core part 10 in the illustrated example. Each flow restricting protrusion 41-47 is located in the interface region between the major channels 31-37 and the rim moulding portion 12 of the mould 2 and is for dividing a major channel into a multiplicity of minor channels in the interface region. Each flow restricting protrusion 41-47 performs the function, in use, of spreading and restricting the flow of plastic towards the rim moulding portion 12 of the mould 2. This is described in further detail below.

A description of how the mould 2 controls the flow of molten plastic in use will now be provided in relation to the first, second and third elongate protrusions 21-23, the first and second major channels 31, 32 and the first and second flow restricting protrusions 41, 42. However, It will be appreciated by the reader that this description applies to any three adjacent elongate protrusions 21-28 and the corresponding major channels 31-37 and flow restricting protrusions 41-47.

Fig. 3 illustrates a close up of a portion of the core part 10 of the mould 2 which illustrates a portion of the interface region between the major channels 31-37 in more detail. The interface region is denoted by the arrow labelled with the reference numeral 71 and two dotted lines. In Fig. 3, the orientation of the core part 10 is the same as that in Fig. 1.

The first elongate protrusion 21 and the second elongate protrusion 22 define the first major channel 31 therebetween. The first flow restricting protrusion 41 is located in the interface region. The first flow restricting protrusion 41 divides the first major channel 31 into a multiplicity of (diverging) minor channels 84, 85 in the interface region.

The second elongate protrusion 22 and the third elongate protrusion 23 define the second major channel 32 therebetween. The second flow restricting protrusion 42 is located in the interface region. The second flow restricting protrusion 42 divides the second major channel 32 into a multiplicity of (diverging) minor channels 86, 87 in the interface region.

In the illustrated embodiment, each elongate protrusion 21-28 has a constant width and a constant height along its length other than in the interface region. However, this need not be the case in every embodiment. The width/height may vary depending upon expected plastic flow in a particular set of circumstances.

The constant width and constant height of the elongate protrusions 21-28 (other than in the interface region) is illustrated in Fig. 3 in the context of the first, second and third elongate protrusions 21, 22, 23 which define the first and second major channels 31, 32. It can be seen in Fig. 3 that as the first, second and third elongate protrusions 21-23 extend towards the rim moulding portion 12 in the interface region, the width of each protrusion 21-23 gradually narrows and the height of each protrusion 21-23 gradually decreases. Each of the elongate protrusions 21-23 has inwardly curving edges 211, 212, 221, 222, 231, 232 that meet at a point in the interface region.

The first flow restricting protrusion 41 has a wall 413 that is for restricting the flow of plastic flowing in the first major channel 31 towards the rim moulding portion 12 and for spreading that plastic across a greater distance in the interface region than the width of the first major channel 31. The distance over which the plastic is spread is substantially perpendicular to the direction of flow of plastic in the first major channel 31. The wall 413 of the first flow restricting protrusion 41 spreads flowing plastic by directing it into the diverging minor channels 84, 85.

The height of the first flow restricting protrusion 41 is at its greatest at the exit of the first major channel 31, where it divides the first major channel 31 into the minor channels 84, 85. As the first flow restricting protrusion 41 extends towards the rim moulding portion 12 in the interface region, it gradually decreases in height and widens because its outer edges 411, 412 curve outwardly, diverging from one another. A converging outer edge 212 of the first elongate protrusion 21 and a diverging outer edge 411 of the first flow restricting protrusion 41 define a first minor channel 84 that extends from the first major channel 31. A further diverging outer edge 412 of the first flow restricting protrusion 41 and a converging outer edge 221 of the second elongate protrusion 22 define the shape of a second minor channel 85 that extends from the first major channel 31. The first and second minor channels 84, 85 diverge from one another in the interface region as they extend from the first major channel 31 towards the rim moulding portion 12.

In the illustrated embodiment, each flow restricting protrusion 41-47 has the same shape as the first flow restricting protrusion 41. However, this need not be the case in every embodiment. Their shapes could be configured differently, for example depending upon expected plastic flow in a particular set of circumstances.

In the illustrated embodiment, as the second elongate protrusion 42 extends towards the rim moulding portion 12 in the interface region, it gradually decreases in height and widens because its outer edges 421, 422 curve outwardly, diverging from one another. A converging outer edge 222 of the second elongate protrusion 22 and a diverging outer edge 421 of the second restricting protrusion 42 define a third minor channel 86 that extends from the second major channel 32. A further diverging outer edge 422 of the second flow restricting protrusion 42 and a converging outer edge 231 of the third elongate protrusion 23 define the shape of a fourth minor channel 87 that extends from the second major channel 32. The third and fourth minor channels 86, 87 diverge from one another in the interface region as they extend from the second major channel 32 towards the rim moulding portion 12.

Each minor channel that extends from a major channel meets and merges with a minor channel extending from a different, adjacent major channel at a position adjacent the rim moulding portion 12. For example, it can be seen in Fig. 3 that the second minor channel 85 meets and merges with the third minor channel 86 prior to reaching the rim moulding portion 12.

The arrow labelled with the reference numeral 51 in Fig. 3 illustrates plastic flowing in the first major channel 31 towards the first flow restricting protrusion 41. When the flowing plastic meets the wall 413 of the first flow restricting protrusion 41, the wall 413 directs some plastic into the first minor channel 84 (as illustrated by the arrow labelled with the reference numeral 52) and some plastic into the second minor channel 85 (as illustrated by the arrow labelled with the reference numeral 54). The remainder of the plastic flowing in the first major channel 31 travels over the wall 413 of the first flow restricting protrusion 41, as illustrated by the arrow labelled with the reference numeral 53 in Fig. 3.

The arrow labelled with the reference numeral 61 in Fig. 3 illustrates plastic flowing in the second major channel 32 towards the second flow restricting protrusion 42. When the flowing plastic meets the wall 423 of the second flow restricting protrusion 42, the wall 423 directs some plastic into the third minor channel 86 (as illustrated by the arrow labelled with the reference numeral 62) and some plastic into the fourth minor channel 87 (as illustrated by the arrow labelled with the reference numeral 64). The remainder of the plastic flowing in the second major channel 32 travels over the wall 423 of the second flow restricting protrusion 42, as illustrated by the arrow labelled with the reference numeral 63 in Fig. 3.

Plastic flowing in a minor channel extending from a major channel meets and coalesces with plastic flowing in a minor channel extending from a different, adjacent major channel. For example, in this regard, plastic flowing in the second minor channel 85 (as illustrated by the arrow labelled with the reference numeral 54 in Fig. 3) extending from the first major channel 31 meets and coalesces with plastic flowing in the third minor channel 86 extending from the second major channel 32.

The purpose of the first and second minor channels 84, 85 and the first flow restricting protrusion 41 is to spread the plastic flowing in the first major channel 31 across a larger distance than the width of the first major channel 31 in the interface region. This causes the thickness of plastic to vary in the region immediately adjacent the rim moulding portion 12 less than would otherwise be the case if the first and second minor channels 84, 85 were not present and instead the first major channel 31 extended to the rim moulding portion 12. The spreading of the plastic adjacent the rim moulding portion 12 helps to ensure that the label 6 is fully secured circumferentially with plastic prior to plastic reaching the rim moulding portion 12.

In effect, each flow restricting protrusion 41 provides flow restricting means that restricts the flow of plastic towards the rim moulding portion 12 of the mould 2 and flow dividing means, for dividing at least some of the flowing plastic into the minor channels that extend around the flow restricting protrusion and to the rim moulding portion 12.

Outer edges of adjacent elongate protrusions that diverge from each other provide enlarging means for enlarging the distance over which plastic from a major channel is spread in the interface region. That is, they cause plastic flowing in the interface region to spread across a greater distance in the interface region than the width of the major channel. For example, outer edges 212, 221 of the first and second elongate protrusions 21, 22 provide enlarging means for enlarging the distance over which plastic from the first major channel 31 is spread in the interface region.

Fig. 4 illustrates a portion of an in-mould labelled plastic container 80 formed using the mould 2. The plastic container 80 comprises a series of alternating elongate ribs and elongate indentations. The elongate ribs correspond with the positions of the major channels 31-37 around the surface 14 of the core part 10 of the mould 2. The elongate indentations correspond with the positions of the elongate protrusions 21-28 around the surface 14 of the core part 10 of the mould 2. The thickness of the plastic container is smaller at the elongate indentations than at the elongate ribs.

Fig. 4 illustrates first and second elongate indentations 121, 122 which correspond in position and were formed by from the first and second elongate protrusions 21, 22. A first elongate rib 131 is positioned between the first and second elongate protrusions 21, 22. The first elongate rib 131 corresponds in position with the first major channel 31. An indentation 141 is present above the first elongate rib 131 which has a position corresponding with that of the first flow restricting protrusion 41. The plastic container 112 also has a rim 112, which was formed by the rim moulding portion 12 of the mould 2.

Advantageously, the plastic container 80 illustrated in Fig. 4 is formed from less plastic than would otherwise be the case if the elongate indentations were not present. This makes the plastic container 80 cheaper to manufacture.

In summary, embodiments of the invention provide a way of manufacturing an in-mould labelled plastic container using less plastic. The mould 2 described above enables a label 6 to be secured to the wall of a plastic container effectively, with minimal movement during the formation of the plastic container, by spreading and restricting the flow of plastic towards the rim moulding portion of the mould 2 in the "interface region" immediately adjacent the rim moulding portion 12. This results in the manufacture of a high quality in-mould labelled plastic container with a premium appearance.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. For example, the elongate protrusions 21-28 and the flow restricting protrusions 41-47 need not be on the same surface 14, as described above. For instance, in some embodiments, the flow restricting protrusions 21-28 could be on the surface 14 of the core part 10 of the mould 2 (as described above) and the flow restricting protrusions 41-47 could be on a surface of the outer part 4 of the mould 2, or vice versa. Where, for example, the flow restricting protrusions 41-47 and the elongate protrusions 21-28 are on different surfaces of the mould 2, the flow restricting protrusions 21-28 are brought into the "interface region" when the core part 10 and the outer part 4 of the mould 2 are co-located (as shown in Fig. 1).

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, 25 those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments 30 whether described or not.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in 5 the drawings whether or not particular emphasis has been placed thereon.

I/we claim:

Claims

CLAIMS1. A mould for producing injection moulded in-mould labelled plastic containers, comprising: a rim moulding portion for use in moulding at least part of the rim of a plastic container; a surface, for use in moulding a wall of the plastic container, having first and second elongate protrusions defining a major channel therebetween; and at least one flow restricting protrusion, located in or for location in an interface region between the major channel and the rim moulding portion, for dividing the major channel into a multiplicity of minor channels in the interface region and for restricting the flow of plastic towards the rim moulding portion.
2. The mould of claim 1, wherein the first and second elongate protrusions are shaped, in the interface region, to cause plastic flowing in the interface region to spread across a greater distance in the interface region than the width of the major channel.
3. The mould of claim 1 or claim 2, wherein the first and second elongate protrusions are shaped to gradually increase the distance over which plastic flows as the first and second elongate protrusions extend, in the interface region, towards the rim moulding portion.
4. The mould of claim 1, 2 or 3, wherein the major channel is defined by an outer edge of first elongate protrusion and an outer edge of the second elongate protrusion, and the outer edges diverge from one another in the interface region as the first and second elongate protrusions extend towards the rim moulding portion.
5. The mould of any of the preceding claims, wherein the height of the first elongate protrusion decreases in the interface region.
6. The mould of any of the preceding claims, wherein the height of the first elongate protrusion gradually decreases as the first elongate protrusion extends in the interface region, towards the rim moulding portion.
7. The mould of any of the preceding claims, wherein the height of the second elongate protrusion decreases in the interface region.
8. The mould of any of the preceding claims, wherein the height of the second elongate protrusion gradually decreases as the second elongate protrusion extends, in the interface region, towards the rim moulding portion.
9. The mould of any of the preceding claims, wherein the at least one flow restricting protrusion comprises at least one wall for restricting the flow of plastic towards the rim moulding portion.
10. The mould of claim 9, wherein the at least one wall is arranged to direct plastic into the multiplicity of minor channels in the interface region.
11. The mould of any of the preceding claims, wherein the height of the at least one flow restricting protrusion decreases in the interface region.
12. The mould of any of the preceding claims, wherein the height of at least one flow restricting protrusion gradually decreases as the at least one flow restricting protrusion extends, in the interface region, towards the rim moulding portion.
13. The mould of any of the preceding claims, wherein the at least one flow restricting protrusion gradually widens as the at least one flow restricting protrusion extends, in the interface region, towards the rim moulding portion.
14. The mould of any of the preceding claims, wherein the at least one flow restricting protrusion has first and second outer edges, and the first and second outer edges diverge from one another in the interface region as the at least one flow restriction protrusion extends towards the rim moulding portion.
15. The mould of any of the preceding claims, wherein the at least one flow restricting protrusion is located on the surface, and is located in the interface region
16. The mould of any of claims 1 to 14, wherein the at least one flow restricting protrusion is located on a different surface of the mould from the first and second elongate protrusions, and is for location in the interface region.
17. The mould of any of the preceding claims, further comprising: a third elongate protrusion and at least one further flow restricting protrusion, wherein the second and third elongate protrusions define a further major channel therebetween, and the at least one further flow restricting protrusion is located in the interface region and is for restricting the flow of plastic towards the rim moulding portion.
18. The mould of claim 17, wherein a first minor channel extending towards the rim moulding portion in the interface region meets a second minor channel extending towards the rim moulding portion in the interface region, at a position adjacent the rim moulding portion.
19. The mould of claim 18, wherein the first minor channel is defined at least partially by an edge of the at least one flow restricting protrusion and a first edge of the second elongate protrusion, and the second minor channel is defined by an edge of at least one the further flow restriction protrusion and a second edge of the second elongate protrusion.
20. A mould for producing injection moulded in-mould labelled plastic containers, comprising: a rim moulding portion for moulding at least part of a rim of a plastic container; a surface, for use in moulding a wall of the plastic container, having first and second elongate protrusions defining a channel therebetween; and flow restricting means, located in or for location in an interface region between the channel and the rim moulding portion, for restricting the flow of plastic towards the rim moulding portion.
21. A mould for producing injection moulded in-mould labelled plastic containers, comprising: a rim moulding portion for moulding at least part of a rim of a plastic container; a surface comprising a channel, having a width for channelling the flow of plastic towards the rim moulding portion; and spreading means for spreading plastic, flowing in the channel towards the rim moulding portion, across a larger distance than the width of the channel in an interface region between the channel and the rim moulding portion.
22. The mould of claim 21, wherein the spreading means comprises flow restricting means, located in or for location in the interface region, for restricting the flow of plastic towards the rim moulding portion.
23. The mould of claim 21 or claim 22, wherein the spreading means comprises enlarging means for enlarging a distance over which plastic from the channel is spread in the interface region.
24. The mould of claim 23, wherein the channel is defined by first and second elongate protrusions and the enlarging means is provided by edges of the first and second elongate protrusions that diverge from each other.