RO132765A2 - Improved machine for manufacturing thin packaging foil - Google Patents

Abstract

The invention relates to an improved machine for manufacturing bags starting from a flexible foil material which is folded and sealed at the bottom. According to the invention, the machine has a device for applying the hardener with liquid adhesive at the bag bottom, it is provided with an adhesive container (6) and at least two stretching cylinders (4 and 5) which can be removed and put in idle state, it also has some means for supply with self-adhesive tape between the so-called pairs of self-adhesive tape guiding and cutting rollers (9), the surfaces of the said rollers (9) being lined with or replaced by an anti-adherent material.

Description

PERFECTED MACHINE FOR MANUFACTURING A PACKING SUBJECT

Field of the invention

The present invention relates to an improved machine for the automatic manufacture of bags of flexible and lightweight material.

Technical state of the art There are many known models of machines for the manufacture of preformed bags, made from a sheet of flexible material, very easy, such as paper or polypropylene. These bags are generally used for packing various products, such as food such as candy, sweets, chocolate, pastries and many other foods or even non-food items.

The bags are made starting from a sheet of foil in the coil, which is properly folded and welded and / or glued, so closed at the bottom of the fold a folding and by the subsequent application of a bottom hardener. The presence of the bottom reinforcer is necessary because, considering the ways of folding the bottom and the intrinsic fragility of the thin material, it contributes to the strength and durability of the bag.

One of the problems encountered during the manufacture of these preformed packages is precisely the formation of the bottom of the bag. Regardless of the technique of making the bottom (see the two examples in the annexed documents fig. 1 and fig. 2), it is indispensable to apply the bottom cardboard (the bottom reinforcer), to maintain the shape and size of the bag and especially to avoid unwanted openings or bottom damage caused by their contents.

the bottom reinforcer may be made of paper, thin cardboard, plastic or cellulose material (cellophane type), aluminum or any other type of thin material, including the same material from which the bag is made; In any case, this bottom reinforcer must be very tightly fastened to the bottom of the bag precisely to ensure it a perfect grip and functionality.

Typically, a machine for making these bags has a section for unfolding the thin foil mother coil from which the bags are made, a section for forming a tube (which may or may not have side bellows), a section folding and bottom formation. in a last step of closing it

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16/02/2017, the preformed bag appears - in a condition that we will not describe in more detail because it is not part of the present invention - to which the paper or plastic bottom reinforcer is applied, generally in rectangular form.

This application operation is currently carried out using a local soldering device. A continuous web of material for the bottom reinforcer that comes from above, passes through a series of guide and processing rolls: in particular, the tape is cut to the size that corresponds to the bottom of the bag and then is applied adhesively on one side - by means of a drum that moistens with the glue inside a liquid glue container - and finally the glue side is applied to the folded bottom of the bag.

This type of "equipment" is not without its disadvantages, mainly because the use of the liquid adhesive necessarily requires the dampening of a series of transfer tools, which leads to the gradual lubrication of the machine and, therefore, involves filling, cleaning and maintenance operations. , several times a day.

Also, in case of system lock or malfunction, the reinforcement sheet - which, as mentioned, is made of a light piece of paper or a plastic film - may slip off the material from which is made up of the bag and to "migrate" uncontrollably inside the different parts that make up the machine, coming into contact with parts of the machine, dirtying them with the glue it contains and causing long enough dead times to stop the machine for cleaning and restart.

It is also mentioned that the very nature of the liquid adhesive does not allow to verify its effectiveness in real time, because it requires a drying period. Therefore, the gluing system also suffers from an intrinsic disadvantage of being able to check its quality only after the production process, after drying the glue, with the risk of continuing the production of a non-conforming material for several hours, material that later it will be eliminated or processed again.

Finally, adhesive consumption, costs and problems related to its storage and management must be taken into account.

To avoid these problems, the use of bottom reinforcements obtained from a self-adhesive support or foil has already been proposed. For this purpose the tape will be used per roll or in "format" of self-adhesive material, or a thin support (of paper or plastic) provided on one side with adhesive. This material, thus avoiding the use of the liquid adhesive, allows a better and immediate bonding of the hardener, thus allowing

3?

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16/02/2017 Carrying out the quality control of the resistance, avoiding the anchoring and stopping times of the machine for cleaning and maintenance and, finally, allows a major production of a higher quality.

However, the use of a self-adhesive tape implies a series of technical knowledge for the proper treatment, guidance and application. Thus, the manufacturers of bag closing machines themselves have proposed on the market complicated and expensive devices for applying the self-adhesive bottom hardener. These devices are intended for mounting on already existing machines as a more precise adaptation, replacing the famous adhesive group with liquid adhesive.

Technical problem and technical solution

The problem underlying the invention is therefore to propose a machine designed for closing the bags with the bottom reinforcer to allow the use of a hardener composed of self-adhesive thin material, but without implying the introduction into the machine of new, complex and expensive equipment.

This object is achieved by the features mentioned in claim 1. The dependent claims describe the preferred features of the invention.

Brief description of the drawings

Other features and advantages of the invention are better highlighted in the following detailed description of an embodiment, presented only by way of example and not exhaustively, illustrated in the accompanying drawings, in which:

FIGS. 1 and 2, as already mentioned, are sketches of typical "cross" and "square" bottom bags whose technique is known;

Fig. 3 is a perspective sketch of a bag machine with known technique, with adhesive feeder;

Fig. 4 is the picture of the same machine of fig. 3 modified according to the present invention.

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Detailed description of the preferred execution methods

For a better understanding of the invention, it was presented in the figure no. 3 a machine having a known technique / technology, and using the system of applying the hardener with the aid of liquid adhesive.

This machine has a carrier chassis 1 on which it is mounted, in addition to the bag carrier group - consisting mainly of a suction conveyor 2 and a bag 3 output drum - and an adhesive applicator group.

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16/02/2017

The latter is mainly composed of a dampening drum 4 and a second adhesive conveyor drum 5 suitably disposed so as to apply liquid adhesive from a container 6 for adhesive positioned at the bottom of a strip that will form the bottom hardener. and which comes from the top of a coil 7 which is supported by the support 7a. The adhesive applicator group is supplemented with the respective movement gears and means for regulating the flow rate of the adhesive supply. In the lower part of the applicator group, above the suction conveyor 2, there is provided an adhesive conveyor 8.

Under the applicator drums 4 and 5 there is provided a group of parallel rollers 9 whose function is to guide the cutting of the strip from which the bottom hardener is composed before it is moistened with adhesive by means of the applicator device positioned above. The rollers 9 are generally mounted singly or in adjacent pairs, one above the other, from a number that varies between one and four or more pairs, controlled by gears positioned at the respective ends. The rollers 9 are generally of hard, wear-resistant material and have surface roughness so as to allow the strip to be pulled, for example, from properly treated stainless metal; the reciprocal coupling of the two rollers within each pair, allows the edges of the grooves to perform the function of guiding and pulling the band from which the bottom reinforcer is composed.

The strip from which the bottom reinforcer is composed, and which is not illustrated in fig. 3, takes place from the upper coil 7, descends and enters between the two guide rollers 10, which pass underneath the container 6 among the pairs of rollers 9 from which it is guided and cut before it comes into contact with the closing bags. which will then stick.

According to the invention, the above-mentioned standard machine will be modified so that it can handle a self-adhesive tape that will form the bottom reinforcer. For this purpose, the entire adhesive applicator group - including components 4, 5 and 6 - will be completely disassembled and removed from the machine. Also, according to the invention, the roller assembly 9 and the drum 8 (which in this case has the role of a contrast drum for the suction conveyor drum) will be treated appropriately with non-adhesive material, such as teflon or similar operations, to prevent the passage. adhesive on the self-adhesive tape on rollers 9 or on the same conveyor drum 8.

A self-adhesive tape coil will be fitted on the 7a support, possibly equipped with a support with Pi adhesive, on which a thin layer of foil will be applied for 2017 00088

16/02/2017 P ₂ protection or film that is easy to remove. The band will lower as usual and will be deflected by the guide rollers 10a and 10b, which in turn are properly treated, at the bottom of them and the eventual layer of protective film P ₂ is removed (see fig. 4), keeping the adhesive part on top, that is in the part from which the bags to be closed will arrive later.

As a result of the deflection caused by the guide rollers 10a and 10b, the Pi band will be inserted between the pairs of rollers within the group of rollers 9. The pairs of rollers 9 perform their usual function of guiding and cutting the bottom hardener belt and interact in a way. perfectly with the Pi tape - despite the existence of the adhesive on contact, due to the treatment of their surface.

As can also be understood from the drawings, due to the elimination of the liquid adhesive application group and due to the treatment applied to the guide and cutting roles 9, it is possible to preserve a simple and economical structure of the feed system, even working with a self-adhesive tape without any problems. .

The outer surface of the rollers 9 and the drum 8 is "Teflon", or - without this term assuming a limiting character - a surface treated in such a way as to result in non-sticking, either because it was made entirely of or was only clothed in Teflon®, either because it was made with any other treatment that gave it the property of being non-sticky, according to the following specifications.

It is important that the non-stick treatment guarantees the smooth gliding of the various self-adhesive strips that are commercially available. Thus, guide rolls that are provided with non-stick material, such as rollers coated in Teflon® or non-stick ceramics, or which have been subjected to surface coating treatment with non-stick substances, such as plasma coating treatments, may be used. , deposition, chemical coating, galvanic coating, hot or laser coating, as well as mechanical works such as the creation of rough grooves or laced grooves, which modify the surface giving space to the non-stick action.

It is possible that other firing drums, such as suction conveyor 2, which are full or segmented, are treated in the same way to make them non-stick.

I

The advantages obtained from the arrangement according to the present invention can be summarized in the following.

First of all, it should be remembered that the present invention offers a solution that can be applied to all currently used machines - that is, to both machines using 2017 00088

16/02/2017 liquid adhesive, as well as those using application groups of the thermofusable type and the like - by making an extremely simple and rapid modification, due to the fact that the parts which are in contact with the self-adhesive tape and which are already present on the the machine in operation can be subjected to a physical-chemical treatment which can be used when using the self-adhesive tape, thus avoiding the use of liquid adhesive and substantially simplifying the machine, as the adhesive application group is eliminated, including the adhesive container and the roller adhesive application.

As an alternative to this treatment, starting from the machine running with liquid adhesive, the solution suggested here can be implemented by a complete replacement of the organs in contact with the sticky part of the self-adhesive tape, with similar organs and / or parts made from non-stick material, such as for example Teflon, sponge, rubber, plastic, ceramic or any type of material having the characteristic of being non-adherent, or even applying to the surface treatments such as making rough grooves, laced grooves, galvanizing and other similar mechanical or chemical or electrochemical operations that give the surface the characteristic of being non-stick.

The machine modified according to the invention allows the use, for the bottom hardener of the bags, of all types of material, including materials such as the usual adhesive tape, products with special adhesive paper, even of the 'no film' type or removable film adhesives, for example, silicone paper, or any other non-stick product. In the case of using a product that has film, as in the example illustrated in FIG. 4, a variable-length wrapping roller will be added to allow the protective film to be wrapped and recovered after detaching from the self-adhesive support.

In any case, it is desired that the invention is not limited to the details mentioned above, which constitute only a few examples related to the importance of the invention, but it is mentioned that numerous variants are possible, all achievable by one skilled in the art, without departing. but from the area of the invention.

Claims (10)

1. Machine for making bags starting from a flexible sheet material folded and closed at the bottom, and comprising a device for applying the bottom hardener on the bottom of the bag, called a hardener because it is made of a thin piece of tape cut at dimension of a pair of guide and cutting rollers, with the following characteristics: the rollers have self-adhesive tape feed means between the so-called guide rollers and cutter strips (9), and the outer surface of the guide and cutter rollers (9) is a non-stick material. The machine for manufacturing the bags according to claim 1, is characterized by the so-called rollers which on the outside are subjected to the teflon treatment. The machine for manufacturing the bags according to claim 1, is characterized by the so-called rollers which are made of non-stick ceramic. I » 4. A bag manufacturing machine according to claim 1, characterized in that the rollers have a surface which has been subjected to the application of non-adhesive material such as those belonging to the group of plasma coating techniques, deposition, chemical coating, galvanic coating, coating. hot or laser. The machine for manufacturing the bags according to claim 1, is characterized by the so-called rollers which have been subjected to a mechanical processing treatment, techniques such as creating rough grooves or laced grooves. A machine according to any one of the preceding claims, wherein the outer surface of a contrast drum (8) for a suction conveyor drum is made of a non-stick surface material. to 2017 00088 16/02/2017 7. Modifying a machine for the manufacture of bags formed from a material of flexible sheet folded and closed at the bottom, the machine having a device for applying the bottom hardener with liquid adhesive on the bottom of the bag, equipped with at least two tensioning cylinders ( 4, 5) and a container containing adhesive (6), the reinforcer being made up of a piece of thin tape cut to size by a group of pairs of guide and cutting rollers, pair with the following characteristics: so that the tensioning cylinders (4, 5) and the adhesive container (6) are removed or put into malfunction, means are provided with a self-adhesive tape between the so-called guide roller and cutting pairs (9), and at least the so-called group of guide and cutting roller pairs (9) have surfaces, either covered or replaced, with a non-stick product. 8. Modification of a bag manufacturing machine according to 7, in which the so-called non-stick product derives from a tefloning process. 9. Kit for modifying a machine for the manufacture of bags formed from a material of flexible sheet folded and closed at the bottom, the machine including a device for applying the bottom hardener with adhesive on the bottom of the bag, equipped with at least applicator drums ( 4, 5) and with an adhesive container (6), the so-called hardener being composed of a piece of thin tape cut to size by a group of pairs of guide and cutting rollers, characterized in that it includes tools and instructions to remove at least the tightening of the tensioning cylinders (4, 5) and the adhesive container (6), to have self-adhesive tape feeding means between the so-called guide rollers and cutting (9) of the belt , and apply at least partially to the outer surface of the so-called guide and cutting rollers (9) a non-stick material. 10. Method of adapting a machine for the manufacture of bags formed from a material of flexible sheet folded and closed at the bottom, the machine including a device for applying the bottom hardener with adhesive on the bottom of the bag, equipped with 2017 00088 16/02/2017 slightly with the tensioning cylinders (4, 5) and with an adhesive container (6), the so-called hardener being composed of a thin piece of tape cut to size by a group of guide roll pairs and debit, characterized by the following phases: remove at least the so-called tensioner cylinders (4, 5) and the adhesive container (6), dispose of self-adhesive tape feed means between the so-called guide rolls and cut-outs (9) of the belt, and at least partially apply a non-stick material to the outer surface of the so-called guide and cutting rollers (9).