GB1560235A

GB1560235A - Device for removing labels from plastic housings

Info

Publication number: GB1560235A
Application number: GB2341977A
Authority: GB
Original assignee: Agfa Gevaert AG
Current assignee: Agfa Gevaert AG
Priority date: 1976-06-05
Filing date: 1977-06-02
Publication date: 1980-01-30
Also published as: FR2353468A1; JPS52149499A; BE855115A; DE2625418A1

Description

(54) DEVICE FOR REMOVING LABELS FROM PLASTIC HOUSINGS (71) We, AGFA-GEVAERT AKTIENGESELLSCHAFT, a body corporate organised under the Laws of Germany of 509 Leverkusen, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a device for removing labels from plastic housings, in particular film cassettes, which device comprises a suction plunger.

There is a wide variety of plastic cassettes on the market. For recognition, these are often supplied with labels, which must be removed when the cassette is reused because they may be damaged or may no longer be applicable to the newly packed product. This is particularly so in the case of the expensive Super-8 film cassettes, which are produced in large quantities.

Many attempts have been made to solve this problem.

Some manufacturers proposed peel-off labels. The adhesion varies according to environmental influences and mechanical strains. If the labels fall off accidentally, then considerable damage can occur to products, in particular to films, whose identity cannot be determined without damage. However if the label is stuck too firmly, then a higher expenditure of labour is required for its removal.

In general, adhesive labels or normal labels with adhesive, which have to be removed manually by scraping, are used.

Thus damage often occurs to the plastic cassette. Clean removal requires much time, which makes recycling of the cassettes very expensive.

It is possible to remove labels which have been fixed with soluble glue, by peeling the labels in a heat bath.

Separation of the peeled label from the housing is difficult. Furthermore, high rising costs are involved in removing completely the remains of the adhesive from even the corners of the housing. A large amount of energy must be expended on final drying, in particular of interlaced cassettes, again making the method very expensive. When using a solvent the danger of dissolving the plastic or of releasing internal tension in the housing arises, and removal or recovery of the solvent causes environmental problems which can only be solved by further expenditure.

In another method, the labels which are used are preferably peeled by means of a heat shock treatment.

Heat shock up to 400 C can produce tensions in plastic housings with a complicated construction, which can result in distortion which makes further use impossible.

Clean removal of all residues of adhesive substances causes problems but this removal is essential for the perfect adhesion of a new label. In certain cases an expensive finishing treatment may be required here.

Unpleasant smelling gases which may be harmful to health and which must be individually extracted and treated, are also produced during heating.

An object of the present invention is to provide a device which allows the used labels to be removed automatically in spite of varying adherence at normal temperatures by a dry method, without harming the plastic of the housing, so that this can be used again without further finishing treatment.

This invention therefore provides a device for removing a label from a plastic housing which device comprises a movable suction plate provided with openings which are connected on one side of the plate to a source of vacuum and surrounded on the other side of the pate by a resilient seal projecting from the plate, which plate is provided with a movable compressed air needle with a nozzle.

It was surprising that a label could be perfectly removed from a cassette by producing a vacuum on one side and elevated pressure on the other side.

Furthermore, it is surprising that the operational efficiency of the device according to the invention is not affected either by further tearing of the thin label or by air leakage, when the label is punctured with the nozzle. The removal of the label takes place so easily that delicate plastics are not damaged and the cassette can be re-used without further operations. The device is very compact and can be installed in a packing line without difficulty. Harmful substances are not produced and in fact the air required as an operating medium simultaneously cleans dust particles which may occur during the stripping process.

Maintenance is simple. Capital and operating costs are low.

In a preferred embodiment, the compressed air needle is spring mounted in the middle of the suction plate, and a seal surrounds the nozzle.

By means of a nozzle which can be lowered centrally, it is possible to fill the space between the label and the cassette uniformly with compressed air, so that the label peels off from the middle towards the edges. The spring mounted plunger ensures by placing the seal on the cassette for a longer time that no leaked air flows from the higher pressure to the vacuum zone, even when the label is thin.

In an alternative embodiment a network of seals is arranged under the suction plate, so that each section of the network has at least one opening into the vacuum zone. By sub-dividing the suction zone with a network of seals it is still possible to remove labels cleanly, even if they are damaged in several places, by means of the adjacent intact sections. On the other hand a damaged section can immediately be recognised by measuring the pressure, so that an additional control can be released if necessary.

In an embodiment, the suction plate is surrounded by an additional spring mounted seal projecting in the same direction as the first projecting resilient seal.

The pressure head is maintained for a short while after removal of the inner covering plate, by means of the additional seal, thus aiding the process of peeling the label.

An embodiment of the invention is shown in the accompanying drawings and is described below in detail.

Figure 1 shows a section through a device according to the invention for the removal of labels.

Figure 2 shows a plan of cassette with housing recess.

Figure 1 shows a plastic cassette 2 with housing recesses 3 in a cassette retaining device 1, over which a label 4 which is to be removed is stuck. A suction plunger 5 is arranged above this, which comprises a suction plate 6 which is provided with several openings 7 which communicate via bores with a vacuum chamber 8 with vacuum connection 9. An additional spring hung seal 18 is placed along the edge of the suction plate 6 in addition to a seal 10.

A vertical movable compressed air needle 11 with a nozzle 12 and a seal 13 is provided in the middle of the suction plate 6, this needle being supplied with compressed air via a compressed air connection 14. The suction plunger 5 can be moved via a piston 15 with a piston rod 16, so that the suction plunger depends from the upper piston surface during the exchange of cassettes and is pressed against the cassette with the lower piston surface during peeling of the label.

The compressed air needle 11 pierces through the label upon contact, by means of the piston rod via spring 17, and is removed from the label before raising the plate. A plastic cassette 2 with housing recess 3 is shown in Figure 2.

EXAMPLE A film cassette was positioned in the cassette retainer, the cassette being covered with a label having dimensions of 32 x 39 mm and having 9 housing recesses of 1 mm width and 0.3 mm depth. The suction plate (28 holes, 2 mm diameter) with a downward projecting seal 4 mm in height was placed on the cassette with the aid of the piston.

The sharp nozzle (1.5 mm diameter) of the compressed air needle penetrated the label into the recesses in the housing. The label was sucked off in 1 to 2 seconds at an air pressure of 3.5 atmospheres gauge and a vacuum of 800 mm water. Cassette and label were removed separately from the device, either manually or automatically. It is of course possible to connect the air pressure and vacuum after each other or to use a vacuum alone.

WHAT WE CLAIM IS: 1. A device for removing a label from a plastic housing, which device comprises a suction plunger provided with a movable suction plate provided with openings which are connected on one side of the plate to a source of vacuum and surrounded on the other side of the plate by a resilient seal projecting from the plate which plate is provided with a movable compressed air needle with a nozzle.

2. A device according to claim 1 in which the compressed air needle is spring mounted in the centre of the suction plate and the nozzle is surrounded by a seal.

3. A device according to claim 1 or claim 2 in which a network of seals is arranged beneath the suction plate so that each

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. elevated pressure on the other side. Furthermore, it is surprising that the operational efficiency of the device according to the invention is not affected either by further tearing of the thin label or by air leakage, when the label is punctured with the nozzle. The removal of the label takes place so easily that delicate plastics are not damaged and the cassette can be re-used without further operations. The device is very compact and can be installed in a packing line without difficulty. Harmful substances are not produced and in fact the air required as an operating medium simultaneously cleans dust particles which may occur during the stripping process. Maintenance is simple. Capital and operating costs are low. In a preferred embodiment, the compressed air needle is spring mounted in the middle of the suction plate, and a seal surrounds the nozzle. By means of a nozzle which can be lowered centrally, it is possible to fill the space between the label and the cassette uniformly with compressed air, so that the label peels off from the middle towards the edges. The spring mounted plunger ensures by placing the seal on the cassette for a longer time that no leaked air flows from the higher pressure to the vacuum zone, even when the label is thin. In an alternative embodiment a network of seals is arranged under the suction plate, so that each section of the network has at least one opening into the vacuum zone. By sub-dividing the suction zone with a network of seals it is still possible to remove labels cleanly, even if they are damaged in several places, by means of the adjacent intact sections. On the other hand a damaged section can immediately be recognised by measuring the pressure, so that an additional control can be released if necessary. In an embodiment, the suction plate is surrounded by an additional spring mounted seal projecting in the same direction as the first projecting resilient seal. The pressure head is maintained for a short while after removal of the inner covering plate, by means of the additional seal, thus aiding the process of peeling the label. An embodiment of the invention is shown in the accompanying drawings and is described below in detail. Figure 1 shows a section through a device according to the invention for the removal of labels. Figure 2 shows a plan of cassette with housing recess. Figure 1 shows a plastic cassette 2 with housing recesses 3 in a cassette retaining device 1, over which a label 4 which is to be removed is stuck. A suction plunger 5 is arranged above this, which comprises a suction plate 6 which is provided with several openings 7 which communicate via bores with a vacuum chamber 8 with vacuum connection 9. An additional spring hung seal 18 is placed along the edge of the suction plate 6 in addition to a seal 10. A vertical movable compressed air needle 11 with a nozzle 12 and a seal 13 is provided in the middle of the suction plate 6, this needle being supplied with compressed air via a compressed air connection 14. The suction plunger 5 can be moved via a piston 15 with a piston rod 16, so that the suction plunger depends from the upper piston surface during the exchange of cassettes and is pressed against the cassette with the lower piston surface during peeling of the label. The compressed air needle 11 pierces through the label upon contact, by means of the piston rod via spring 17, and is removed from the label before raising the plate. A plastic cassette 2 with housing recess 3 is shown in Figure 2. EXAMPLE A film cassette was positioned in the cassette retainer, the cassette being covered with a label having dimensions of 32 x 39 mm and having 9 housing recesses of 1 mm width and 0.3 mm depth. The suction plate (28 holes, 2 mm diameter) with a downward projecting seal 4 mm in height was placed on the cassette with the aid of the piston. The sharp nozzle (1.5 mm diameter) of the compressed air needle penetrated the label into the recesses in the housing. The label was sucked off in 1 to 2 seconds at an air pressure of 3.5 atmospheres gauge and a vacuum of 800 mm water. Cassette and label were removed separately from the device, either manually or automatically. It is of course possible to connect the air pressure and vacuum after each other or to use a vacuum alone. WHAT WE CLAIM IS:

1. A device for removing a label from a plastic housing, which device comprises a suction plunger provided with a movable suction plate provided with openings which are connected on one side of the plate to a source of vacuum and surrounded on the other side of the plate by a resilient seal projecting from the plate which plate is provided with a movable compressed air needle with a nozzle.

section of the network has at least one opening to the vacuum connection.

4. A device according to any of claims 1 to 3 in which the suction plate is surrounded by an additional spring-mounted seal which projects in the same direction as the projecting resilient seal.

5. A device for removing a label from a plastic housing substantially as herein described with reference to the accompanying drawings.

6. A device for removing a label from a plastic housing substantially as herein described with reference to the Example.