WO2002085735A1

WO2002085735A1 - Container lid for a reclosable container, a method and an apparatus for the manufacturing of the lid

Info

Publication number: WO2002085735A1
Application number: PCT/SE2002/000783
Authority: WO
Inventors: Bertil Abrahamsson
Original assignee: Superfos Packaging Tenhult Ab
Priority date: 2001-04-23
Filing date: 2002-04-23
Publication date: 2002-10-31
Also published as: SE0101411L; SE0101411D0

Abstract

Lid (1) for a reclosable container, which lid comprises a lid part (6) and an accessory (7) in an integrated part, which lid (1) displays a continuous surface, where the lide (1) further comprises a covering layer (10), which is melted together with the lid part (6) and the accessory (7) and covers the part of the lid (1) where the accessory (7) is arranged, where the lid (1) displays a complete, tight surface when the accessory (7) has been removed.

Description

Container lid for a reclosable container, a method and an apparatus for the manufacturing of the lid

TECHNICAL FIELD

The present application relates to a lid for a reclosable container, which lid comprises a lid part and an accessory in an integrated part, which lid has a complete surface. The invention also relates to a procedure and device for its manufacture.

BACKGROUND ART

Reclosable containers of the kind that are intended to contain foodstuff are usually equipped with a lid of a thermoplastic material. They are often portion packets, intended to contain a smaller amount of food for consumption at one or a few occasions. Typically, the foodstuff that this kind of container contains is of the kind that is eaten at lunch at working sites or outdoors, so-called fast food. The contents may by way of example be yoghurt, salad or other precooked dishes.

In order to simplify for the consumer, the container is often equipped with a piece of cutlery in order to pick up and/or eat the foodstuff that is in the container. Thus the consumer does not need to remember to buy and bring a separate piece of cutlery. The piece of cutlery is usually made of wood or plastic and is usually attached to the container inside a plastic covering or spot-glued to the container.

Equipping a container with a piece of cutlery in the manner described above presents a problem, as it is associated with high production costs. Another problem is that the piece of cutlery has to be attached to the container in some way, and stay there until the consumer wishes to remove the piece of cutlery. With the attachment methods described above, it is unsure whether the piece of cutlery remains when the consumer is about to eat the foodstuff. The piece of cutlery may simply have fallen off, or been removed in some other way.

It has thus been proposed to form the lid of the container and the piece of cutlery in one piece, by way of example by means of injection moulding. A moulding tool is designed in such a way that a lid part and a piece of cutlery is formed at the same moment. The melted plastic is injected through several injection spots that are positioned at different places at the moulding tool, and forms the piece of cutlery. The plastic is transported further via channels between the parts of the moulding tool in which the lid part is formed and the parts in which the piece of cutlery is formed in order to form the lid part. The result is that the lid part and the piece of cutlery are attached to each other by means of the plastic that is present in these channels. With this procedure a more economical manufacture of the piece of cutlery and a container equipped with a piece of cutlery that is better attached to the container is acquired.

There are, however, other problems associated with this latter kind of construction. As the lid part and the piece of cutlery are injection moulded in one and the same piece, the lid will no longer display a complete surface towards the surroundings when the piece of cutlery has been removed from the lid part. The lid will display a hole where the piece of cutlery has been removed. This is of course a large problem, as the container no longer can be considered as reclosable when the piece of cutlery has been removed. A consumer can not eat a part of the portion in the container using the piece of cutlery and then reclose the container by means of the lid with the intention of eating the rest of the portion later, without having to accept that it is in contact with the surroundings during the storage. DISCLOSURE OF INVENTION

The present invention eliminates the problems mentioned above and produces a lid to a reclosable container that displays a complete, tight surface when the piece of cutlery that is placed in the lid has been removed. This purpose is achieved owing to that the lid further comprises a covering layer, which is melted together with the lid part and the piece of cutlery and covers the part of the lid where the piece of cutlery is arranged. A complete surface means that the lid displays a complete surface towards the surroundings thus closing the reclosable container when the lid is put on the container. A tight surface means that the surface is leakproof, in such a way that a liquid can not penetrate the surface if the container should be placed on its lid. This means that the container must not display any slot or hole where a liquid may come through. If necessary, the surface may be made to be leakproof for gases, such as air. The fact that the covering layer covers the part of the lid where the piece of cutlery is arranged means that it at least covers the part of the lid that exactly coincides with the contour of the piece of cutlery. If the covering layer and the lid part shall form a complete, tight surface when the piece of cutlery has been removed, there is a need for the covering layer to extend beyond the contour of the piece of cutlery. The extension beyond the size of the piece of cutlery that is needed varies with the dimensions of the lid and the piece of cutlery, and also depends on the material that is chosen, but normally the covering layer should have to extend 3-7 mm beyond the contour of the piece of cutlery.

The lid is produced with so-called IML technology (In Mould Labelling technology). This means that the covering layer has been moulded into the upper side of the lid. Placing the covering layer in the moulding tool in a moulding injector where the lid shall be manufactured may perform this. At the manufacturing process for the lid, the covering layer is melted to the lid. The lid part, the piece of cutlery and the covering layer are melted together and display a complete surface. The covering layer may be used to contain information concerning the product that shall be contained in the container, i.e. be used as a label. Hence the name "in mould labelling" follows. When the IML technology mentioned above is used for manufacturing the lid, the accessory and the covering layer may be made to be melted together.

A reclosable container according to the invention does not have to contain foodstuff, but other products that are desired to be enclosed in a reclosable container and which also need some kind of tool to handle are also conceivable. Examples of such products are for example sanitary napkins or compresses for treatment of wounds. For hygienic reasons it may be desirable to remove these two kinds of articles from the container using a pair of tweezers or a similar tool. Cutlery or other tools will therefore in the following be called accessoriess.

According to a preferred embodiment of the invention, the lid part and the accessory are injection moulded into one integrated part in the moulding tool in an injection moulding device. The term integrated means that the parts are joined together when the material that they are made from is in a melted condition. The covering layer is also integrated with the other lid parts when the covering layer is placed in the moulding tool when the other parts are present in a melted state and the covering layer is thus joined to the other lid parts when they are in a melted condition. The accessory is advantageously placed on the side of the lid that in use is facing towards the inside of the container. Thus it is avoided in one more way that the accessory is removed too early, since it may not be removed until the container has been opened. During injection moulding, the lid belonging to the reclosable container is made by filling it through one single injection point in the moulding tool placed in the part of the moulding tool where the accessory is formed. That is, both the lid part and the accessory are filled through this injection point. It is possible to have more injection points, but the more injection points that are used, the more difficult it gets to get the covering layer smooth when it is melted together with the lid. One injection point is therefore preferred. Preferably, the injection of material only takes place via one single injection point located in the centre point of what will later form the lid. That means that the injection point will coincide with the part of the moulding tool in which the centre point of the lid is formed. This point may also coincide with the centre point of the accessory, but the accessory may also be placed on the lid in a non-centred manner. The injection point is of course a physical location in the moulding tool, but also a visible point on the detail that has been manufactured.

In order to provide a higher degree of stability for the accessory in order to improve its use as, by way of example, a piece of cutlery, the moulding tool may be designed in such a way that the thickness of the material for the accessory is made to be greater than for the lid part. It is important that the filling of material is performed in an even manner in the different parts of the moulding tool. Most preferably the filling should be performed as if there were no accessory present. The spreading of material from an injection point would then take place in such a manner that the whole outer contour of the lid is reached by material at the same time. How the spreading front for the material shall look like becomes dependent on the geometry of the lid. If the lid is circular, the spreading front for the material shall be circular, if the lid is square, the spreading front shall be square. This is the objective according to the invention. Since an accessory is going to be formed, adjustments should therefore be made. Therefore the moulding tool is preferably designed in such a way that the filling of material in the lid part is made in such a way that the lid part will display a thickness of the material which varies in the area surrounding the accessory. How this variation is made becomes dependent on the geometry of the accessory that is going to be formed. In order to facilitate that the covering layer shall be applied smoothly in the process, the moulding tool is suitably designed with venting means.

When the lid shall be filled from one single injection point placed in the part of the moulding tool in which the accessory is formed, it is required that there is at least one channel in the moulding tool for transport of material from the accessory recess in the moulding tool to the lid part recess. This is preferably arranged by forming two channels in the moulding tool, which channels are located in such a way that they are placed at each side of the of the centrally arranged injection point. Depending on the type of accessory that is manufactured, the number of channels may vary. When the lid is made, this means that two connection means are formed, which are separate from each other, and which are integrally designed with the lid part and through which the lid part and the accessory become connected. There may also be more connecting means between the lid part and the accessory. The more channels, the more connecting means. Other types of connecting means may also occur, by way of example created by the filling of material in the venting means of the moulding tool.

According to an alternative embodiment of the invention, the lid part and the accessory may be made in different materials. The lid part may for example be made in a kind of polypropylene plastic and the accessory may be made in another kind of polypropylene plastic with a higher degree of rigidity than the kind of polypropylene plastic that is used for the lid part. The lid part and the accessory are then injection moulded in a way known to the man skilled in the art, by injecting one of the details in one part of the tool in an injection unit, then the tool is moved to a new injection unit where the other detail is injected in another part of the tool. The details are melted together where they meet. In this way, the accessory may be made to be more rigid than if it had to be made in the same material as the lid part, which has to be relatively flexible in order to be reclosable. An alternative to this is to make the complete lid in a material with sufficient rigidity for the accessory and to adapt the closing construction between the lid and the container in such a way that it works with a material with such a high degree of rigidity.

According to an extraordinarily preferred embodiment of the invention, the lid displays an arcuate cross-section at the area for the accessory. This provides an increased stability for the accessory. It is also possible to design the cross-section with other forms deviating from the plane than the arcuated, in order to increase the stability for the accessory.

As mentioned above, the accessory may for example be a pair of tweezers for removal of a compress or a piece of cutlery for removal of food from the container and/or for eating the food. The accessory may for example be a piece of cutlery such as a spoon, a fork or a knife. The accessory is as mentioned earlier suitably arranged on that side of the lid that will face the inside of the container when it is closed. To admit that the consumer is able to see that the container is equipped with an accessory, without making it possible to remove it from the outside of the container, it is preferably arranged in such a way that the accessory is visible through the covering layer. This may, by way of example, be achieved by embossing the contour of the accessory on the outer surface of the covering layer or by visualizing it in some other way, such as offset printing in the form of the contour of the accessory.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows a lid according to the invention viewed from the side of the lid that is directed inwards the container when it is applied to the container.

Figure 2a shows a cross-section along the line ll-ll of the lid in figure 1.

Figure 2b shows a magnification of figure 2a.

Figure 3 shows a lid according to the invention viewed from the side of the lid that is directed outwards towards the surroundings when it is applied to the container. MODES FOR CARRYING OUT THE INVENTION

In figure 1 a lid 1 according to the invention is shown. The lid 1 has a circular outer contour 2. The shape of the container that it will be fastened to determines the circular outer contour 2 of the lid. The outer contour of the lid may just as well have a square, oval, rectangular or other shape, according to what is desired. The lid 1 has two sides, an inner side 3 that faces towards the inside of the container when the lid is applied to a container, and an outer side 4, that faces outwards towards the surroundings when the lid is applied to a container. Along the outer contour 2 of the lid, the lid is designed with a flange 5 for snap-in closure to a container (not shown). The locking of the lid 1 to a container may be made in an arbitrary way within the frame of the invention, the way shown in figure 1 only constitutes an example.

The lid 1 is made in polypropylene plastic, but it is of course possible to choose any material that meets the parameters that are important for the field of application and the production method, within the frame of the invention.

The lid 1 comprises a lid part 6 and a spoon 7. As stated above, the accessory does not have to be a spoon, but other pieces of cutlery and tools may also be integrated into a lid according to the invention.

The spoon 7 displays a longitudinal centre line 8 and a transverse centre line 9. The spoon 7 is placed centred in the lid 1. That is, the intersection between the longitudinal centre line 8 of the spoon and its transverse centre line 9 coincide with the centre point of the lid 1. The meaning of the centre point is that the distance between this imaginary point and the outer contour of the lid is the same independent of where it is measured. The spoon 7 constitutes an integrated part of the lid 1. The meaning of integrated is that the spoon 7 is made in a piece of material continuous with the lid part 6 of the lid 1. The spoon 7 is placed on the first side 3 of the lid. This means that the spoon 7 will be out of reach from the outside when the lid 6 is placed on the container. The length and size of the spoon 7 depends on the size and the design of the lid and, further, of course, on the dimensions of the container.

In figure 3 the lid 1 is shown from its exterior 4, the side which faces the surroundings when the lid 1 is applied to a container. On the outer side of the lid, a covering layer 10 is placed. This is made using IML technology, which means that the covering layer has been put in the moulding tool in which the lid 1 shall be injection moulded. The heat from the melted plastic that is injected in the moulding tool, melts together the covering layer with the lid 1 and is thus integrated with this. The covering layer 10 also constitutes a label for the lid 1 , which means that there is information applied to it. The covering layer 10 is made of a special kind of polypropylene, Synteape FPG 150, made by Oji Yuka. It is of course possible to use different materials, but there are heavy demands upon the material that shall be used for the covering layer 10. The reason for this is that the covering layer 10 not shall wrinkle during the manufacturing process and be sufficiently melted together with the spoon 7 in order to adhere it to the covering layer 10, while it still is removable for the potential customer.

In figure 1 the injection point 11 on the spoon 7 is shown. The injection point is the point through which the plastic has been supplied to the lid 1. Both the lid part 6 and the spoon 7 have been filled through the same injection point 11. One single injection point had thus been used. This is important in order to bring the covering layer 10 to melt together with the lid part 6 and the spoon 7 without having wrinkles forming in the covering layer 10. In order to transport the melted plastic from the spoon 7 to the lid part 6 there are two channels in the moulding tool. The plastic that remains there when the lid 1 is formed constitutes two connecting means 12, 13. These are situated on each side of the injection point 11 , along the transversal centre line 9 of the spoon. The lid part 6 and the covering layer 10 are melted together. The spoon and the covering layer 11 are melted together. When the consumer wishes to remove the spoon 7 from the lid 1 , she/he presses the outer surface 3 of the lid at the area for the spoon 7 and then tears the spoon from the covering layer. The merging between the covering layer 10 and the spoon 7 is of the kind that allows such a detachment. The connecting means 12, 13 between the spoon 7 and the lid part 6 are broken when the spoon 7 is removed from the covering layer. When the spoon 7 has been removed from the lid 1 the lid would no longer display a complete surface if the covering layer 10 had not been there. The covering layer thus has to be of such a size that it covers the spoon 7, in order for the lid 1 to be complete even after the removal of the spoon.

Figure 1 shows that the areas on the lid part 6, which surround the spoon 6, have different thickness of the material. In the areas 14a, 14b, 14c and 14d which are most adjacent to the connecting means 12, 13, the lid part 6 has a greater thickness of the material then in the peripheral area 15 of the lid part 6. In connection with the spoon 7b and the areas 14a, 14b, 14c and 14d, but farther from the transversal centre line 9 than these there are further areas 16a, 16b within which areas the lid part 6 has a greater thickness of the material then in the areas 14a, 14b, 14c and 14d. Peripherally outside the areas 14a, 14b, 14c and 14d there are further areas 17a, 17b, 17c, 17d within which the lid part 6 has a greater thickness of the material then in the peripheral area 15. The areas 17a-d have a lesser thickness of the material than the areas 14a-d. The cause of the variations of the thickness of the material of the lid part is that the plastic shall spread circularly during the filling of the moulding tool.

In figure 2a and 2b a cross-section of the lid in figure 1 is shown. Figure 2b is an enlargement of figure 2a. The lid 1 displays a cup-shape 18 at the area where the spoon 7 is attached. This may also expressed as the lid 1 having an arcuate cross-section. As the lid part 6 and the covering layer 10 are designed to have arcuate cross-sections, the spoon also has an arcuate cross-section. The spoon 7 displays a cup-shape. This cup-shape or corrugation is made in order to bring an enhanced rigidity to the spoon. Figure 3 shows a contour 19 of the spoon 7 on the outside 4 of the lid 1. This contour is imprinted in the covering layer 10 of the surface 20 that during use is intended to face outwards from the lid 1, in other words on the outer surface 20 of the covering layer. Making this imprinting visualizes for the consumer that there is a spoon inside the container.

The invention is in this case visualized by what is shown in the figures, but shall not be considered to be limited to what is shown there. The accessory may, by way of example, be placed in the lid in a manner that is different from the central placement that is shown.

Claims

1. Lid (1) for a reclosable container, which lid comprises a lid part

(6) and an accessory (7) in an integrated part, which lid (1) displays a continuous surface characterized in that the lid (1) further comprises a covering layer (10), which is melted together with the lid part (6) and the accessory (7) and covers the part of the lid (1) where the accessory

(7) is arranged, where the lid (1) displays a complete, tight surface when the accessory (7) has been removed.

2. Lid (1) for a reclosable container according to claim 1, characterized in that the lid part (6) and the accessory (7) have been injection moulded into one integrated part.

3. Lid (1) for a reclosable container according to claim 2, characterized in that it is equipped with only one common injection point (11) placed in the accessory (7).

4. Lid (1) for a reclosable container according to claim 3, characterized in that the injection point (11) is centrally placed in the lid (1).

5. Lid (1) for a reclosable container according to claim 3 or 4, characterized in that the accessory (7) and the covering layer (10) are melted together.

6. Lid (1) for a reclosable container according to claim 4, characterized in that the lid part (6) has a thickness of the material that varies in the area surrounding the accessory (7).

7. Lid (1) for a reclosable container according to claim 1, characterized in that the lid part (6) and the accessory (7) are connected by two connecting means (12), (13) separate from each other, which are designed to be integrated with the lid part (6) and the accessory (7).

8. Lid (1) for a reclosable container according to claim 1, characterized in that the lid part (6), the accessory (7) and the covering layer (10) are made in polypropylene.

9. Lid (1) for a reclosable container according to claim 1, characterized in that the lid part (6) and the accessory (7) are made in different materials.

10. Lid (1) for a reclosable container according to claim 1, characterized in that the lid (1 ) displays an arcuate cross-section at the area for the accessory.

11. Lid (1) for a reclosable container according to any one of the preceding claims, characterized in that the accessory (7) is a piece of cutlery such as a spoon, a fork or a knife.

12. Lid (1) for a reclosable container according to any one of the preceding claims, characterized in that the accessory (7) is visible through the covering layer (10).

13. Lid (1) for a reclosable container according to claim 12, where the covering layer (10) displays an outer surface (20) intended to face the surroundings when the lid (1) is placed on the container characterized in that the contour (19) of the accessory is embossed on the outer surface (20) of the covering layer.

14. Procedure for manufacture of a lid (1) for a reclosable container which lid comprises a lid part (6) and an accessory (7) which together form a continuous surface where the lid part (6) and the accessory (7) are injection moulded into an integrated part in a moulding tool, characterized in that injection takes place via an injection point placed in the part of the moulding tool where the accessory is formed.

15. Procedure for manufacture of a lid (1) for a reclosable container according to claim 14, characterized in that the injection point is placed in the part of the moulding tool where the centre point of the tool is formed.

16. Procedure for manufacture of a lid (1) for a reclosable container according to claim 15, characterized in that the forming of the accessory (7) takes place before the forming of the lid part (6).

17. Procedure for manufacture of a lid (1) for a reclosable container according to claim 15 or 16, characterized in that a covering layer (10) is placed in the moulding tool and is melted together with the lid part (6) and the accessory (7).

18. Injection moulding device for manufacture of a lid (1) for a reclosable container comprising a moulding tool for injection moulding where the moulding tool is equipped with a recess for the forming of a lid part (6) and a recess for the forming of an accessory (7) and at least one channel between these recesses enabling the lid part (6) and the accessory (7) to be formed into one integrated part characterized in that the moulding tool is equipped with an injection point arranged in the part of the moulding tool where the accessory is formed.

19. Injection moulding device according to claim 18, characterized in that the injection point is arranged in the part of the moulding tool where the centre point of the lid is formed.

20. Injection moulding device according to any one of the claims 18 or 19, characterized in that the moulding tool is equipped with two channels for transport of material between the recess that forms the accessory and the recess that forms the lid part.

21. Injection moulding device according to any one of the claims 18 or 19, characterized in that the moulding tool is equipped with at least one venting means.