WO2008047305A2

WO2008047305A2 - Multipack carry handle and method for producing such handles

Info

Publication number: WO2008047305A2
Application number: PCT/IB2007/054203
Authority: WO
Inventors: Maria Van Tilborg; Marcel Schaaders; Pierre Thijs
Original assignee: Supertape B.V.
Priority date: 2006-10-20
Filing date: 2007-10-16
Publication date: 2008-04-24
Also published as: WO2008047305A3

Abstract

A novel carry handle for use at a pack of wrapped containers is described, which comprises a length of plastic adhesive material with a reduced length of laminated foam expandable material.

Description

Multipack carry handle and method for producing such handles

The invention is related to a multipack carry handle according to the general clause of claim 1 and a method for producing and applying such a handle to a multipack according to the general clause of claim 4.

Multipacks of bottles of mineral water or soft drinks with a carry handle are well- known in the market. The base material of such a carry handle is a pressure sensitive adhesive tape based on polyester, polypropylene or any other plastic material capable of holding the weight of multipack without breaking or stretching. For the production and applications of carry handles to multipacks a tape spooled to a roll with a length of 5000 meters or more and a width of e.g. 25 mm is used. A plain or printed carton strip is laminated onto a piece of tape and the adhesive ends of the tape are placed to the multipack. The rolls of tape are normally supplied to the bottling companies who apply the tape on special machines at the end of the bottling and packaging line.

A more recent development is a pre-laminated tape, on which the carton or paper strip is already laminated on the pressure adhesive tape by the tape manufacturer. The pre-laminated tape is configured on rolls of e.g. 5000 meters. As the length of the insert is shorter than the length of the total tape applied onto the pack, the two ends of the tape remain adhesive to adhere to the pack. For production and application of the carry handles novel application machines have been designed or existing machines have been adapted. This development offers to the bottling companies and to the consumers certain advantages. The bottling company does not have to worry anymore about machine disturbance caused by the lamination of carton strips shortly before applying the handles to the multipacks. Pre-lamination enables to laminate not only carton strips but also paper or plastic strips. It also ensures that the laminated strips are always in line with the edges of the tape. For the consumer such carry handles offer more comfort, as the materials are more pliable and the cartons are not extending over the edges of the tape. Thus, there will be less chance of cutting hand or fingers. A further development in production of carry handles is inspired by the requirement of bottling companies and consumers to request even more comfort than offered by pre-laminated tapes. One of the options in this respect is the replacement of carton, paper or plastic strips by using a foamed material. In general the foamed material is applied by the bottling company in line with the filling and packaging lines. The foam material can be laminated as such or in combination (pre-laminated) with a printed paper. In general the foam is supplied in flat rolls or spools. The thickness of the foam can vary between 1 and 3 mm. The foam can be based on polyolefin, polyurethane or any other suitable plastic material that can be foamed. The polyolefin foams can be non-crosslinked or can be crosslinked chemically or physically.

The aforementioned approach has several disadvantages:

- If the foam material is supplied onto flat rolls, the diameter of the roll will be very large and/or the length is limited.

- If the foam material is supplied onto spools, the dimension of the spool will be very large.

- Transport of this voluminous material will be more expensive.

- For processing of this material special machines are needed. Also adaptation of the current machines is not so easy. This mainly because of the large dimensions of the rolls/spools and the different processes needed. The strips are to be cut in a certain length and applied on a certain position onto the tape automatically; this process is called from roll to roll lamination.

- The fact that there is a limited number of meters on a roll or spool of foam implies that there will be a lot of roll changes at the bottler's plant. This adds complexity and more chances of disturbance to the bottler's processes.

- Because of the thickness of the foamed material it is almost impossible to make a tape with a pre-laminated foam strip as done in the second generation carry handle tapes (with carton or paper strips). It is an object of the present invention to provide carry handles for multipacks which are much more comfortable to handle and which can be manufactured in a simple manner.

This object is accomplished by the carry handle with the features as defined in claim 1 and by a method for producing and applying such a handle to a multipack with the features of claim 4.

The present invention has the main advantage, that thanks to the foaming or blowing agent the dimensions of the spooled tape rolls to be used remain more or less the same so that any change in the production machines is not necessitated.

Further advantages of the invention are disclosed in the dependent claims and in the following description in which an exemplified embodiment of the invention is described with respect to the accompanying schematic drawings. It shows

Fig. 1 laminating of a polymer matrix with a foaming agent onto a base plastic sheet material,

Fig. 2 cutting of the non-expanded coated material and laminating of certain lengths thereof to a tape material, and

Fig. 3 heating the laminated material for expanding the lengths of coated material and cutting into handles.

Description of the invention

In a first concept according to Fig. 1 a roll 1 of a base plastic sheet material 2 of e.g. mono-oriented polypropylene or bi-oriented polypropylene, polyester or paper is unwound and coated with a polymer matrix like natural or synthetic rubber, polyurethane, polyolefin, acrylic or the like material mixed with a foaming or blowing agent, the blowing or foaming agent is mixed to the polymeric material in a relation of 1 :20 to 1 :3, preferably 1 :10 to 1 :5. This polymeric mixture 3 is filled in a container 4 from which a feed line 5 with a pump 6 is connected to a spraying apparatus 7 for coating onto the base material 2. Optionally, a heating apparatus or curing lamps 9 are provided in flow direction behind the coating or spraying apparatus 7 in order to dry or crosslink the polymeric mixture 3, called "prefoam". The settings of the drying or curing apparatus should be in such a way that no foaming will occur in this prefoaming process. The coated prefoam material 10 will then be wound onto a roll 11.

Fig. 2 shows the further processing of the roll 1 1 wherein the coated material 10 will be cut be means of a knife 14 and a counterpart 15 into pieces 16 which are laminated by pressing rolls 17 and 18 with a predetermined pressure (arrows A and B) in predetermined intervals 19 onto a tape of adhesive material 20 wound on a roll 21 The so laminated material 22 is wound onto a roll 23. The winding velocity of the roll 23 is slightly higher than the unwinding velocity of the roll 11 in order to provide the intervals 19 between successive pieces 16.

As an alternative concept the mixture of polymeric material and foaming or blowing agent can be coated directly on the base tape in discontinuous strips with the same dimensions as the laminated material 16 and in intervals 19 (Fig. 2). In this way the processes of coating the prefoam mixture (Fig. 1 ) and the lamination of prefoamed material (Fig. 2) are combined in one process. The use of the base sheet material 1 of Fig. 1 is not necessary anymore.

Thereafter the flat roll 25 (as an outcome of the first concept or of its alternative) is unwound and the laminated material 22 is fed through a heating tunnel or section 26 in which the pieces 16 of the polymeric matrix 3 are heated to a predetermined high temperature (e.g. 130 °C) so that the volume of the foaming or blowing agent will expand about four to ten times dependent on the exposure time and the properties of the blowing agent, resulting in expanded thicker pieces 27. Appropriate blowing agents are e.g. Expancel of Akzo Nobel or any blowing agent of Dupont de Nemour. The extent of expansion of the foam depends on the quantity of blowing agent in the foam, the exposure time and the temperature level. The temperature at the process of coating of the base sheet material with a layer of material to be foamed has to be much lower than the temperature at which the blowing agent will react, i.e. expand. The expansion can occur chemically or physically. By "chemically" is understood the process in which certain chemicals are added to the prefoam, which will react during heating and form gases that will expand the prefoam to the expanded foam material. By "physically" is understood the process in which e.g. expandable microballoons or microcapsules are added to the prefoam. Under influence of heat these microballoons will expand and transform the prefoam to the normal foam material.

The expanded thicker pieces 27 are thus located on the tape of material 20 which will be cut at the intervals 19 by means of a knife 28 and a counterpart 29 to form the carry handles 30 for further processing, i.e. adhering to the plastic material of the wrapped plastic bottles, tin containers or the like, which are normally filled with a fluid like mineral water, soft drinks, beer, etc.

Since the dimensions of the so produced tape rolls 23 viz. 25 are comparable with the rolls used today for providing handles any constructive changes in the unwinding machine design is not necessary. The unwound tape will run through a heating tunnel or section in which the foam will expand and afterwards a handle is cut-off at the desired length and applied to the sides of the pack of plastic bottles. In such a manner a more voluminous and more comfortable carry handle will be provided which can readily be applied.

The main advantage of the above mentioned production process are that the volume of the tape rolls remains the same as in the known processes and thus no further volume is needed for transportation. The length of spools can be maintained at the actual length (e.g. 5'00O meters) , so that there is no decrease of line efficiency. The production machines must not be adapted with exception of a heating tunnel or section 26.

Claims

1. Carry handle for use at a pack of wrapped fluid containers, comprising a length of plastic adhesive material with a reduced length of laminated foam expandable material.

2. Carry handle as claimed in claim 1 , wherein the foam expandable material comprises a natural or synthetic polymeric material mixed with a blowing agent or other materials expandable at a predetermined temperature.

3. Carry handle as claimed in claim 1 , wherein the blowing or foaming agent is mixed to the rubber material in a relation of 1 :20 to 1 :3.

4. Process of applying a handle to a pack of wrapped fluid containers comprising unwinding a roll of adhesive tape having at predetermined intervals pieces of expandable prefoam material of predefined length, cutting a length of tape between two successive intervals for obtaining a piece of expandable foam material with adhesive ends, heating said length of tape at a high temperature in order to expand the foam material and applying the adhesive ends of the tape length at both sides of a pack of wrapped fluid containers.

5. Process as claimed in claim 4, wherein the length of tape is heated in a heating tunnel after unwinding an before application to the pack of wrapped fluid containers.