LU86632A1 - METHOD FOR CLOSING THE END OF A TUBE AND PLANT FOR APPLYING THE METHOD - Google Patents

Description

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METHOD FOR CLOSING THE END OF A TUBE AND PLANT FOR APPLYING THE METHOD

The object of this invention is a method for closing the end of a tube made of plastic or laminated from aluminum foil layers and plastic layers, which tube for storing and metering e.g. Toothpaste or cosmetics is used, as well as a plant for applying the method.

There are three main types of tubes for storing and dosing toothpaste or cosmetics or the like. In the past, tubes made of light metal, especially aluminum, were common. For them, the closing of the tube end was generally done in such a way that several folds were made on it. However, a seam of this type is not safe enough because it often happens that the aluminum tube breaks during use at the seam of the tube end.

Plastic tubes in which the jacket qanz is made of elastic plastic are very common. The advantage of such a tube is that it keeps its shape when in use, making it very suitable for cosmetics used in feminine beauty care because its appearance remains aesthetic.

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Today, laminate tubes are generally also used, in which the - jacket made of plastic layers laminated on top of one another

Aluminum foil layers - Unlike a tube made entirely of plastic, the shape of a laminate tube changes in use due to the aluminum foil layers. Polyolefins, e.g. LD or HD — polyethylene or polypropylene. Closing the end of a plastic or laminate tube is usually done e.g. so that the open end of the jacket, which is essentially circular or oval in cross section, is gently warmed and pressed shut. The facing sides of the coat; are siselled together. The strength of the seam is the same as the tear resistance of the inner, sealed plastic. However, it cannot be considered sufficient, since the longitudinal seam of the jacket of the tube, manufactured according to the latest varing methods, can even withstand twice as much pressure as the end of the tube.

The seam of the tube end is of flavors of the substance in the tube, e.g. the toothpaste, weakened, which over time eat at night. It has been empirically possible to determine that the strength of the end seam is half

Year drops to half the original strength. It is clear that such observations have given rise to the 3rd

Examine the structure of the end seam more closely. For a better understanding of the invention now made and the advantages achieved with it, it is appropriate to explain the reasons why today's seam does not hold.

The length of the seam is usually about 5-iö cm. After closing, the seam is even and its cross-section is linear. If pressure is created in the tube, the seam will tear because the strength of the seam is insufficient to prevent the walls of the jacket from moving apart. The tearing is also over time by; above mentioned flavors that eat at the seam promoted. The

The crack becomes larger with an oval cross-section until an opening is created in the seam of the tube end.

The purpose of this invention is to provide a method of closing the end of a plastic or laminate tube so that it can withstand greater stress than before. In addition, the purpose of the invention is to create a plant for using the method. The method according to the invention is characterized in that the open end of a tube which is open at least at one end is flattened, folded and sealed by heating the folded end at least on the side 'where the outer surface of the fold is located and the fold and the rest of the end of the tube is pressed together.

4th

A favorable form of application of the invention; The process is characterized in that the end of the tube is sealed on both sides.

A favorable application form of the method according to the invention is characterized in that the open end of the tube is cut obliquely before folding in such a way that the side of the jacket against which the end is folded is shorter, which is why the end of the fold after folding is even.

A favorable form of application of the invention; The method is also characterized in that the open end of the tube is cut at an angle before folding so that the side of the jacket against which the end is folded is considerably shorter, which is why after folding and sealing the outer surface of the fold with the flat of the coat, which is on the side of the fold, unites.

The system for using the method according to the invention is characterized in that for the system a conveyor device that conveys the tubes in a vertical position, the end to be closed upwards, into a folding device that folds the end of the tube, and a sealing device , which consists of at least one hot element and a press.

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A favorable application form of the system according to the invention is characterized in that cooling and stamping devices are arranged in the system after the sealing device.

Another favorable form of application of the system according to the invention is characterized in that the conveyor consists of a foam rubber belt and a conveyor belt.

A favorable application form of the system according to the invention is further characterized in that the folding device consists of two turntables arranged one after the other.

The conclusion reached according to the invention has the advantage that the cross section of the tube end always remains line-like and no tearing can occur, since the opposite sides of the jacket cannot move apart. The reason for this is that a seam is also created outside the tube between the fold and the tube. Even flavors of the substance in the tube cannot penetrate into the finish. The conclusion according to the invention withstands a considerably greater stress than known seams, since its strength is the same as the tensile strength of the entire laminate.

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Another important advantage of the method according to the invention is that the closing takes place on an uninterrupted movement path running in the same direction and no jerky movements to and fro are required.

The invention is explained below on the basis of favorable application form examples, reference being made to the attached drawings, where

1 shows a plant which uses the method according to the invention, partially in section seen from above,

Figure 2 shows the step along the line II-II of Figure 1,

Fig. 3 shows the section along the line III-IIÏ of Fig. 1,

4 shows the section along the line IV-IV of FIG. 1, FIG. 5 shows the section along the line V-V of FIG. 1, FIG. 6 shows the section along the line VÏ-VI of FIG. 1, 7

7 shows the section along the line VII-VII of FIG. 1,

Fig. 8 shows the section along the line VIII-VIII of Fig. 1,

Fig. 9 shows the section along the line IX-IX of Fig. I,

10 shows a known seam of the tube end cut,

11 shows a section of the end of the tube end, which is formed by means of the method according to the invention and a system using this method.

Fig. 12 shows a favorable embodiment of the invention.

In Figure 1, a system according to the invention is shown partially in section seen from above. The system includes foam rubber bands 1, which convey the tubes 2 in a vertical position so that the end to be closed points upwards. The tubes 2 are made of the desired material, e.g. Toothpaste or equivalent filled. When the tubes come between two conveyor belts 3 arranged opposite one another, the end of the tube is flattened and the conveyor belts 3 convey the tubes

Tubes 2 further into a folding device consisting of two; there are turntables 5, 6 arranged one behind the other. The first

Turntable 5 bends the end of the tube so that it is at an angle of 90 degrees from the vertical position, and second turntable 6 completes the folding in the manner shown in FIG. After the folding device, the end of the tube 2 is bent.

Between the turntables, the tube continues to be positively controlled in the position shown in FIG. 5. This prevents the fold from straightening out again. After the second turntable 6, the tube also continues in a force-controlled manner into a sealing device which consists of two movable sealing bands 7 which are located opposite one another and are designed such that they run over hot elements 8 and press the end of the tube. In order to hold the sealing tapes 7 firmly in the vertical direction, the sealing device is provided with wires 9 countersunk on the inner surfaces of the heating element 8, with which the tapes 7 e.g. are connected by vulcanization. The hot elements 8 are provided with heat cartridges, from which the heat is conducted through the hot elements and tapes to the folded end of the tube to be sealed. As the end of the tube heats up, it is pressed tightly together by means of the sealing strips 5. In the 9th

Connection with Figures 11 and 12 explained in more detail. According to the invention, it is also possible that there is only one hot element 8. It is best arranged on the side where the fais is located.

In addition, cooling and stamping discs 11 can be arranged at the end of the system. With the stamp disc you can e.g. the manufacturing number can be printed.

FIG. 10 shows a tube end which is closed using the method which is most common today. In it, the seam 12 is formed between the holders 13 and 14 of the jacket. The seam is made by heating the seam and pressing the seam tightly between cold cheeks.

FIG. 11 shows a closure of the tube end produced using the method according to the invention. The jacket 13, 14 is a tube with a substantially circular cross section before the end is made. In the invention, the jacket is either made entirely of plastic material or laminated from layers of plastic and aluminum which are placed one on top of the other. As the plastic material can be cheapest. Polyolefins, e.g. LD or HD polyethylene or polypropylene can be used. In the figures, a tube 10 is shown, the jacket of which is laminated, the number of aluminum foil layers 15 being two. The number of aluminum foil layers 15 is arbitrary per se and in no way limits the invention. It is convenient to cut the end of the jacket a little obliquely so that it is shorter on the side against which the end of the tube is to be bent. This enables the ends of the halves 13 and 14 of the jacket to be at the same level after the bending. The seam 16 arises between the outside of the halves 13 of the jacket and the inside surface of the fold. The seam 17 arises within the fold between the two halves 13 and 14 of the jacket. If necessary, the end of the tube can also be sealed on the other side, creating a mow between the halves 13 and 14 of the jacket before the fold. This is the case in the application form examples in the figures, but this is not absolutely necessary for the strength of the end.

In Figures 10-12, the size of the conclusion is very exaggerated for reasons of drawing technology and for the sake of clarity of the figures. E.g. the dimension L of FIG. 11 is in reality approx. 4-5 mm and the dimension S is approx. 1 mm. In natural size, the lower edge of the fold is not as round as shown in Figures 11 and 12, but sharp.

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In Figure 12 is a favorable application of the invention. 'in which the end of the jacket 13, 14 is cut at an angle before the folding so that after the folding and sealing the outside 19 of the half 14 of the jacket merges with the outside of the half 13 of the jacket »This creates a more beautiful appearance achieved and the strength of the end even improved «Otherwise, the structure of the tube end is the same as in the application form example shown in Figure 11, ie when sealing on both sides, seams 16, 17 and 13 are created.

It is clear to a person skilled in the art that the invention is not limited to the above-mentioned application form examples, but that it can be varied within the scope of the following claims.

Claims (9)

12 1.Method for closing the end of a plastic or e.g. Tube (2) made of aluminum foil layers and plastic layers, which tube for storing and dosing e.g. Tooth passport or cosmetics is used, characterized in that the open end of a tube (2) which is open at least at one end is pressed, folded and sealed by means of continuous positive control, in that the folded end is at least on the side where the outer surface of the fold is located, is heated and the fold and the remaining part of the tube end are pressed against each other. 2. The method according to claim i, characterized in that the end of the tube (2) is sealed on both sides. 3. The method according to claim i or 2, characterized in that the open end of the tube (2) is cut obliquely before folding so that the side of the jacket against which the end is folded is shorter, which is why after folding End of the fold is even. 13 4. The method according to claim 1 or 2, characterized in that the open end of the tube <2) is cut obliquely before folding so that the side of the jacket against which the end is folded is considerably shorter, * which is why after Folding and sealing unites the outer surface (19) of the fold with the surface of the casing which is on the side of the fold. 5. Plant which uses the method corresponding to patent claim 1 for closing the end of a plastic or e.g. Tube (2) laminated from aluminum layers and plastic layers, to which system a conveyor (1, 3, 4) with which the tubes are transported up the open end, a folding device (5, 6) and a sealing device (7, 8) belong, characterized in that between the conveyor (1,3,4) and the folding device (5, 6) and between the folding device (5, 6) and the sealing device (7, 8) positive control devices are arranged and that the conveyor, the Folding device and the sealing device and the above-mentioned positive control devices are adapted to convey the tubes (2) through the entire system at a substantially constant speed. 14 6. System according to claim 5, characterized in that the conveyor consists of a foam rubber band (1) and conveyor belts (3, 4), which flatten the open end of the tube between each other. 7. Installation according to claim 5 or 6, characterized in that the folding device consists of a bending disc (5) which bends the end of the tube (2) by 90 degrees, a positive control device which conveys the tube and a bending disc (ό) which bends the previously bent part by 90 degrees, thereby bending the end of the tube. 8. Installation according to claim 7, characterized in that the positive control device arranged between the bending disc (£>) and the sealing device (7,8) conveys the tube (2) with the end bent into the sealing device. 9. Plant according to one of claims 5-8, characterized in that the sealing device from mutually arranged, movable sealing tapes (7), which form a press for the tubes (2), and at least one hot element (8), in which heat cartridges < 10}, from which the heat is conducted through the sealing tapes to the end of the tube. 15 »solve Installation according to one of the claims 5-9, characterized in that cooling and stamping devices <11) are arranged in the installation after the sealing device <7, 8).