EP1644145B1 - Method and device for the production of a can body, and can body - Google Patents

Abstract

The aim of the invention is to produce can bodies (24') comprising a can shell (24) and a closing element (31b, 32, 31a) that is fixed to one face of the can shell (24). Said aim is achieved by producing a tube (11) from a metal strip (1), optionally from directly adjacent sections (112), by means of a shaping step, at least one optional cutting step, and a continuous welding step, sections of said tube (11) being used as closed convex surfaces for cans. The sections are shaped by a shell-shaping device in such a way that can shells (24) are provided into which a closing element (31b, 32, 31a), especially a can bottom (31b), can be inserted. The longitudinal seam (11a, 124) can be produced inexpensively and at great precision essentially as a continuous seam in the welding step by means of simple installations.

Description

The invention relates to a method according to the preamble of claim 1, to a device according to the preamble of claim 17 and to a can body according to the preamble of claim 20, see, for. B. DE A 1452556 ,

Vessels with metallic walls or with jacket and bottom, in particular aerosol cans with a decor, are formed in one or more parts. In the case of one-piece aerosol aluminum cans, the cylindrical can body is provided by means of cold extrusion. Subsequently, a valve seat is formed at the open end by upset necking. This manufacturing process is very expensive due to the required for the many processing steps and the water and energy requirements for cleaning and drying. The US 4,095,544 and the EP 0 666 124 A1 describe the production of seamless steel cans. In this case, the cylindrical can body is produced by means of stamping, pressing and ironing out of a tin or plastic-coated steel sheet. It has been found that enormous problems occur when forming constricted neck parts because the material structure is changed or hardened by the stretching. Also widely used are cans made of sheet steel, in which the jacket has a longitudinal weld. The bottom and the upper end are fastened to the can jacket via seam connections. When seaming joints sealing problems can occur, which are reduced approximately with sealing rings. In the usual extremely thin-walled cans arise with frontally arranged seals problems. From the scriptures EP 200 098 A2 and EP 208,564 are two- and multi-part doses known in which the parts are connected by laser welding. The predetermined by the known laser welds shape design of the cans in the connecting areas between the can wall and bottom or valve seat are unattractive and also can be achieved with sufficient quantities per unit time with the known methods no cost production. The longitudinal welds described, in particular also from the US 4,341,943 known laser welds, have small steps or differences in thickness in the circumferential direction, which lead to problems at the can body and increased stress on the constriction tools in the constriction of the neck portion.

From the WO02 / 02257 A1 For example, a method of forming a neck portion is known in which a deformation surface cooperates with a support surface to deform the can wall between these two surfaces under tensile forces. The deformation surface is thereby moved radially inwardly, wherein the can wall is always in contact with the radially inner abutting support surface. It has now been found that the gap area between the surfaces resting against the can wall on both sides must be exactly matched to the wall thickness which is variable in this area, and furthermore that the tensile forces in the can wall must be selected continuously so that the constriction does not lead to a bead , In the case of a bead, the forces acting on the can wall by the two surfaces would become very high locally, which would entail a risk of damage. It has been found that maintaining the proper conditions at the constriction with cooperating deformation and support surfaces is very difficult.

In the common can bodies, in addition to the constriction of the neck part, a narrowing at the transition to the bottom surface is desired. Because in the formation of the neck part usually the soil is already used, the constriction in the bottom area is conveniently made in advance, which is difficult on a can jacket without upper or lower degree.

For aesthetic reasons and to mark the content, a decoration is attached to the outside of the lateral surface. To be able to dispense with a complex and inflexible direct printing of the can body, printed films are applied to the can body. According to the EP 0 525 729 a decorative film is wound in the circumferential direction directly on the can body and connected to the can body to form a closed film envelope. The separation of a piece of film is very difficult with thin films. To connect the ends of the film with a sealing compound, a sealing surface is pressed against the can body, which is not practical in thin-walled cans due to the too small stability. For cans whose outer surface is narrowed at the lower and in particular at the upper can end, or deviate from a cylindrical surface, the formation of a hull-free sealed joint over the entire can height is not possible.

From the scriptures US 4,199,851 . DE 197 16 079 and EP 1 153 837 A1 Solutions are known in which shrinkable plastic sheet material wound around a mandrel, formed into closed envelopes and pushed as wrap-around labels in the axial direction on a bottle or box and shrunk tight. The clamp-free shifting The wrap-around labels on the bottles or cans is associated with various problems, especially for thin films. In the in the EP 1 153 837 A1 mentioned thin decorative films with a thickness of less than 25 .mu.m, preferably between 9 .mu.m and 21 .mu.m, the deformation and damage when moving the closed film covers from the winding mandrel on the can body is very large. The printable, commercially available plastic film Label-Lyte ROSO LR 400 from Mobil Oil Corporation comprises a thin sealing layer on both sides and is available in a thickness of 20 μm and 50 μm. When sealing the overlap region, the sealing layer applied to the winding mandrel is also heated and pressed against the winding mandrel. In the field of sealing strip, the film now has different sliding properties. Further problems may arise from frictional electrostatic charges and the associated electrostatic forces acting on the foil. The transfer of the cylindrically closed film from the mandrel to a can body is problematic, even if the diameter of the winding mandrel is slightly larger than the diameter of the can body. A significant difference in size is not desirable because otherwise the shrinkability of the film must be greater and there is a risk that form hulls during shrinkage. To increase the shrinkability, a film with a greater thickness would also have to be used, which is not desirable. Another problem is that thin films can be separated only with great effort. Already due to the difficult separation solutions in which pieces of film are wound around a mandrel or a can body, not desirable.

Out DE 14 52 556 It is known to form a metal strip with transverse slots around a mandrel-like carrier to form a closed shell and to heat the merged sides with a high-frequency heating current to the desired temperature and thereby connect. Subsequently, cuts are made in the slots to obtain can coats. The production of attractive cans is not described.

The known solutions for producing cans use complex systems and are also dependent on the operation of specialized personnel. The cans therefore can not be produced at the bottling plants. There is a great transport effort to transport the empty cans from the can manufacturer to bottling plants.

The present invention has for its object to find a solution with the aesthetically attractive cans can be produced inexpensively and with simple facilities.

This object is solved by the features of claim 1, or of claim 17, and of claim 20. The dependent claims describe preferred or alternative embodiments. Can bodies are to be understood as meaning all vessels, in particular also tubes and vessel-shaped intermediate products. When solving the problem was found according to claim 17, a method for forming a neck portion at the open can end, according to claim 16 a method for setting a dose termination valve, according to claim 22, a can body with a valve seat and according to claim 23, a can body with a can end with valve Which objects are new and inventive, regardless of the can production.

In solving the problem, it was recognized in a first inventive step that a longitudinal seam can then be formed particularly efficiently and with extremely high quality, if it can be produced continuously over long longitudinal expansions. A longitudinal seam can be produced continuously over a large longitudinal extent if the longitudinal seam is welded to directly adjacent, circumferentially closed can jacket surfaces or during pipe production. After welding, the adjoining canned coats can be separated from each other, with the seam possibly having to be cut off. From a pipe, the closed lateral surfaces are separated as pipe sections.

A tube is preferably made of a metal strip, for example according to the DE 198 34 400 produced. A forming device continuously shapes the metal strip so that the two side edges come into contact with each other, and the welding device welds these side edges together. The deformation of the strip into a tube shape is preferably carried out by bending the strip in its transverse direction about a tube axis parallel to the longitudinal axis of the tube. The cross-sectional shape can be chosen during forming so that the welding can be carried out efficiently. Pipe is to be understood as meaning around an axis leading, closed lateral surfaces. In a preferred embodiment, a flattened tube is made, preferably two incisions are formed in the band perpendicular to the ribbon axis before forming in the flat band. These cuts are arranged so that they lie in the curved areas of the flattened endless can jacket after a forming step of the strip. As a result, cutting can be restricted to the flattened area between the curvature areas when separating the desired can jacket sections.

The metal strip is unwound from a roll and can therefore have a very large length. If the roll change is solved so that the beginning of the new roll connects directly to the end of the old role, so can be assumed that a continuous pipe production. In this case, the longitudinal seam can be formed essentially as an uninterrupted seam with great precision. .

In the processing of panels, sections of the size of a can jacket are first severed. From these sections, closed can coats can be formed. In a preferred embodiment, these can jackets are flattened with two regions of curvature. The longitudinal seam is welded to sections directly adjacent to each other. Directly adjoining sections with the same cross-sectional shape form a tube.

The welding device preferably remains stationary and the tubular shaped metal sheet is moved past the welding device. Various welding methods can be used to form the seam. Preferably, however, the seam is produced by means of laser welding. The edges of the metal strip connected by the welding meet, if appropriate, overlapping, but preferably blunt or butt each other. In the case of a blunt connection, steps or thickness differences can also be avoided in the region of the seam, so that a substantially constant wall thickness of the tube in the circumferential direction is ensured. This is particularly advantageous for the formation of a narrowed neck portion. Sections of the length of the desired can height are separated from the continuously formed tube.

In a second inventive step, it has been recognized that in a continuous tube for separating the tube sections, which are further processed as a can jacket, preferably a new and inventive separation method can be used. The known separation processes are sawing processes. In this case, a release agent, such as a cutting disc or a saw blade, carried along with the resulting pipe during the sawing process. After separating a pipe section, the release agent is reset. Due to the short pipe sections that are needed in a can manufacture, the known separation devices are not sufficient because they can not separate and reset quickly enough. Another disadvantage of the known separation devices is that when separating especially thin-walled pipes there is a risk of deformation and thus jamming. In addition, in the known separation processes sawdust, which would make additional cleaning steps would be necessary and / or could make problems in the further can manufacturing steps.

If the resulting tube is flattened for new and inventive separation of the pipe sections, then a cutting method can be used advantageously for thin sheets. In this case, for example, the flattened tube is guided on a base, which can cooperate with a cutting edge. Once the desired length of the pipe section is advanced, the cutting edge is moved with the pipe and by cutting through the abutting wall portions of the pipe by moves. When cutting no chips and the cutting process is extremely fast, so that the cutting edge after the return movement away from the support surface even with short pipe sections in the tube longitudinal direction can be moved back sufficiently fast to execute in time the next cutting operation. With a firmly positioned in the direction of the tube axis cutting edge must be ensured that the tube can bend due to the fixation at the cutting edge in a deflection so that the retained feed is absorbed as a bending extension in the bending region. After cutting, the deflection is compensated by a slightly increased feed rate of the pipe end in the separator. It goes without saying that cutting methods are also possible in which the tube is not pressed flat.

If the tube is already provided with a decorative film during the separation of the pipe sections, the decorative film can be separated directly together with the stability-giving part of the can jacket. This can be dispensed with a separate separation of thin film pieces. The decorative film could be applied to the metal sheet before pipe formation, but then the film in the longitudinal seam would be affected when welding the longitudinal seam. If necessary, the film is first applied to the welded pipe. This is preferably done by feeding a film strip in the direction of the tube axis, wherein the film strip is folded around the tube in the circumferential direction, so that the two film edges abut each other or slightly overlap. The adhesion of the decorative film to the pipe is achieved approximately with a sealing process. The attachment of a developable in the tube longitudinal direction of the film web on the outside of the resulting tube is much easier than the wrapping of pipe sections with pieces of film. Right next to each other following, circumferentially closed can jacket surfaces can be coated like a tube with a film outside.

If the starting material - the panels or the tape - is provided with a decorative film and / or an inner film, the film can be separated directly when cutting the open or closed shell sections together with the stability-giving part of the can jacket. This can be dispensed with a separate separation of thin film pieces.

If the decorative film is applied to the metal sheet before the longitudinal seam is formed, it can be prevented with additional processing steps, an impairment of the decorative film during welding of the longitudinal seam. For example, the decorative film can be arranged on the flat material so that it does not extend to the end face at one edge region and protrudes beyond the end surface at the other edge region. The above film region is not firmly sealed in an edge region of the flat material, so that this free film edge can be transferred away from the region of the weld seam before the formation of the weld seam. After the welding process, the free edge of the film can be placed over the weld seam and sealed tightly. As a result, the longitudinal seam is completely covered. It has been shown that for welding the longitudinal seam lasers can be used, which form only a very narrow seam. In the area of a narrow seam, the decorative foil can be removed with another laser. It can be dispensed with a film-free edge area and the decorative film over the entire width are applied to the metal sheet.

After the separation of pipe sections with or without decorative film, these pipe sections are pushed by a shell molding device so that can coats stand ready, where a floor can be used. The rupture can ensure a desired cross-sectional shape, and if the overall circumference is slightly increased, a desired reduction in wall thickness can also be achieved. The reduction of the wall thickness can also be used as an exact approximation to a desired wall thickness. During rapping, it was recognized that not only the desired cross-sectional shape can be embossed, but that when a widening of the cross-section at the can end against which a widening tool is moved, a cross-sectional constriction can be expressed from the widened to a smaller or original cross-section. Such a small constriction would be to form advantageous connections between the can jacket and a Can bottom very suitable. The constriction would expediently be formed with a radius of curvature which corresponds to a shape prevailing in aerosol cans in the transition from the can wall to the bottom of the can.

In a can jacket with a provided at aerosol cans small constriction at the can end a can bottom can be applied to the narrowed edge region and connected with a circumferential weld tightly with the can jacket. If the bottom of the can from the inside of the can is applied to the constriction and welded, so you can see in a standing on a support surface box only the narrowing of the can wall against the support surface. The inserted bottom of the can is not visible. The can has the appearance of an aluminum monobloc can in the area of the bottom of the can.

Because no material-hardening treatments have been performed in the manufacture of the can jacket, a necking process known in the art, such as neck-necking or spin-flow necking, may be performed at the top of the can jacket. This constriction can be carried out until the formation of the valve seat. Preferably, however, only a constriction is performed so far that a closing element with the valve seat at the upper narrowed end can be arranged tightly. Optionally, the connection is formed as a folded connection, but preferably as a welding, in particular as a laser welding connection. The insertion of a closure element with valve seat ensures the production of cans with an extremely accurate valve seat with a simple manufacturing process.

Because a shoulder-shaped constriction on an end face of the can jacket and a correspondingly shaped edge region of the closing element is required for the dense pressing of a closure element to the can jacket can be at least one, optionally on both end faces each an annular bulge radially outwardly pronounced. This creates a cross-sectional constriction against the respective end face. On one end face, the bottom of the can and on the other end side, an upper end element can be firmly welded to the respective constriction. Preferably, the floor is first welded. Before or optionally after the welding of the upper end element of the can jacket can still be reshaped, for example, in which the can cross section is widened at least to the diameter of the at least one bulge. Prior to the welding of the upper end element forming tools, such as rollers, can be introduced into the can interior to expand the can jacket. Optionally, a fluid is introduced under pressure into the can interior to expand the can cross-section and pressed the can jacket in an inner mold, which, for example, from the patents EP 853 513 B1 . EP 853 514 B1 and EP 853 515 B1 is known. Other methods known in the art for expanding and forming a can jacket may also be used.

Optionally, a bottom cover is used so that the connection of the can jacket is covered with the bottom of the can through them. Preferably, the bottom cover is made of plastic sheet material. It goes without saying that flat material with at least one metal, in particular aluminum or steel layer, or even with a cardboard layer can be used. Here is the stability-giving Layer optionally coated with plastic. The flat materials used are intended to ensure a robust bottom cover, which is not damaged on the conveyors of the filling systems and remains as stable as possible when standing on wet documents. The bottom cover may be provided with a sealing layer so that it can be sealed to the ground. Instead of a sealing connection, a catch connection or a welded connection, in particular with at least three laser welding points, may also be formed to secure the bottom cover. If a magnetizable bottom cover is used, then this can also allow for can bodies made of non-magnetizable material promotion with magnetic conveyors.

The production of a can body with decorative film is particularly advantageous when using a film which is optionally printed on its outside or front side, but preferably on the side facing the can body or back. With a transparent film printed on the back, the print layer is protected by the film, so that no impairment of the decor due to friction can occur. A printed on the back of a transparent transparent film can be provided after printing on the print layer with a sealing layer, which also ensures a firm seal connection through the print layer between the film and the can body and in the overlap region between the film edges.

It may be advantageous if the printing layer on the backside of the film substantially performs the function of a primer and the remaining decoration is printed on the front side of the film. Now, if it is spoken of primer, this can only be a monotonous base color or even a part of the decor, for example, the flat color or the image design. The preprinted on the back in a first printing film web is printed in a further printing step on the front. This further printing step can optionally be carried out at the can manufacturer, or in a second printing company, in order to apply specific decor information. This means, for example, that labels are applied to a basic décor in the further printing step, which are different for the respective sales markets. For printing on the front side, it is possible to use any printing method known from the prior art, optionally with surface treatments carried out after printing.

Fig. 1

eine schematische Darstellung einer Anlage zum Herstellen von Dosenkör- pern,

Fig. 2a

einen Schnitt durch ein Metallband mit aufgelegter Kunststofffolie und einem Nahtabdeckband,

Fig. 2b

einen Schnitt durch ein Rohr, das aus dem um die Längsachse umgeboge- nen Metallband gemäss Fig. 2a gebildet wurde,

Fig. 2c

einen Schnitt durch ein Rohr gemäss Fig. 2b nach dem Flachdrücken,

Fig. 2d

einen Ausschnitt aus dem flachgedrückten Rohr gemäss Fig. 2c,

Fig. 2e

einen Ausschnitt gemäss Fig. 2d nach dem Festsiegeln des Nahtabdeckban- des,

Fig. 3a

einen Schnitt durch ein flachgedrücktes Rohr mit einer um das Rohr umgelegten Kunststofffolie,

Fig. 3b

einen Schnitt durch ein flachgedrücktes Rohr an das Pressrollen eine umge- legte Kunststofffolie pressen,

Fig. 3c

eine Draufsicht auf die Anordnung gemäss Fig. 3b,

Fig. 4

eine Schnittdarstellung einer zylindrischen Dosenwand mit darin angeordnetem Aufweitzylinder in zwei Positionen

Fig. 5

eine schematische Draufsicht auf eine Bearbeitungsstation, bei der Dosen auf einem Drehteller mit einem Abschlusselement verbunden werden,

Fig. 6a

eine Bearbeitungsstation gemäss Fig. 5 mit Lichtleiterkabeln für die Laser- schweissung,

Fig. 6b

eine Seitenansicht einer Bearbeitungsstation gemäss Fig. 5 mit Lichtleiterka- beln für die Laserschweissung,

Fig. 7

einen Schnitt durch eine Haltevorrichtung für eine Bearbeitungsstation ge- mäss Fig. 5 mit einem Dosenkörper an dem der Boden eingesetzt wird,

Fig. 8

einen Schnitt durch eine Haltevorrichtung für eine Bearbeitungsstation ge- mäss Fig. 5 mit einem Dosenkörper an dem das obere Abschlusselement eingesetzt wird,

Fig. 9a

einen Schnitt durch eine Verengungsvorrichtung mit zwei Situationen am An- fang eines Verengungsvorganges,

Fig. 9b

einen Schnitt durch eine Verengungsvorrichtung mit zwei weiteren Situatio- nen während des Verengungsvorganges,

Fig. 9c

einen Schnitt durch eine Verengungsvorrichtung mit zwei Situationen am Ende des Verengungsvorganges,

Fig. 9d

eine schematische Draufsicht auf eine Verengungsvorrichtung gemäss Fig. 9a,

Fig. 10a

einen Schnitt durch einen Dosenkörper einer Aerosoldose mit eingesetztem Boden und aufgesetztem Ventilsitz,

Fig. 10b

eine Seitenansicht eines Dosenkörpers mit speziellem Erscheinungsbild,

Fig. 11a

einen Schnitt durch eine Tube mit eingesetztem Gewindeteil,

Fig. 11b

einen Schnitt durch eine Tube mit aufgesetztem Gewindeteil,

Fig. 12

einen Schnitt durch den oberen Endbereich einer Aerosoldose mit einem neuartigen Ventiladapter,

Fig. 13

einen Schnitt durch den oberen Endbereich einer Aerosoldose mit zwei verschiedenen Ventilsitzen, und

Fig. 14

einen Schnitt durch den unteren Endbereich eines Dosenkörpers mit einer Bodenabdeckung.

Fig. 15a

einen Vertikalschnitt durch einen Dosenmantel mit Ausbuchtungen bei beiden Stirnseiten,

Fig. 15b

einen Vertikalschnitt durch einen Dosenkörper mit Ausbuchtungen am Dosenmantel und daran fest geschweissten Abschlusselementen,

Fig. 16

einen Vertikalschnitt durch eine Aerosoldose mit einem oberen Abschlusselement mit Ventil,

Fig. 17

einen Teil eines Vertikalschnittes durch eine Aerosoldose mit einem oberen Abschlusselement mit Ventil,

Fig. 18a

eine schematische Draufsicht auf eine Trennvorrichtung, die aus Tafeln Streifen schneidet,

Fig. 18b

eine schematische Seitenansicht einer Vorrichtung zum Anbringen von Folien auf beiden Seiten der Streifen,

Fig. 18c

eine schematische Draufsicht auf einen Anlageteil der aus Streifen Abschnitte schneidet und diese in flachgedrückte Dosenmäntel umformt,

Fig. 18d

zwei schematische Querschnitte von Bearbeitungsschritten zum Umformen von Abschnitten in die flachgedrückte Dosenmantel-Form,

Fig. 19

eine schematische Seitenansicht einer Anlage, die bandförmiges Flachmaterial beidseitig mit Folien beschichtet und das Bandmaterial kontinuierlich in eine flachgedrückte Dosenmantel-Form bringt,

Fig. 19a

eine Draufsicht auf das Flachmaterial nach dem Anbringen von Einschnitten,

Fig. 19b

einen schematischen Querschnitt im Bereich von Umformelementen zum Umformen des Bandmaterials in die flachgedrückte Dosenmantel-Form,

Fig. 20

einen Querschnitt der flachgedrückten Dosenmantel-Form,

Fig. 21

eine schematische Schnittdarstellung des Schrittes zum Aufbringen eines Abdeckbandes,

Fig. 22

einen schematischen Querschnitt einer Vorrichtung zum Laserschweissen der Dosenlängsnaht,

Fig. 23

einen vergrösserter Ausschnitt aus Fig. 5,

Fig. 24

eine schematische Seitenansicht eines Anlageteiles zum Laserschweissen der Längsnaht, Anpressen des Abdeckbandes, Schneiden und Konditionieren von geschlossenen Dosenmantelabschnitten,

Fig. 25

einen Querschnitt durch eine Vorrichtung zum Anpressen des Abdeckbandes,

Explain the drawings.

Fig. 1

1 a schematic representation of a system for producing can bodies;

Fig. 2a

a section through a metal band with applied plastic film and a Nahtabdeckband,

Fig. 2b

a section through a pipe, which consists of the um¬ around the longitudinal axis umgeboge- metal strip according to Fig. 2a was formed,

Fig. 2c

a section through a pipe according to Fig. 2b after flattening,

Fig. 2d

a section of the flattened tube according to Fig. 2c .

Fig. 2e

a section according to Fig. 2d after the sealing of the seam covering band,

Fig. 3a

a section through a flattened tube with a folded around the tube plastic film,

Fig. 3b

press a cut through a flattened tube onto the press rollers, a folded plastic film,

Fig. 3c

a plan view of the arrangement according to Fig. 3b .

Fig. 4

a sectional view of a cylindrical wall of cans with arranged therein expansion cylinder in two positions

Fig. 5

a schematic plan view of a processing station, are connected in the cans on a turntable with a closure element,

Fig. 6a

a processing station according Fig. 5 with fiber optic cables for laser welding,

Fig. 6b

a side view of a processing station according Fig. 5 with fiber optic cables for laser welding,

Fig. 7

a section through a holding device for a processing station according to GE Fig. 5 with a can body on which the bottom is inserted,

Fig. 8

a section through a holding device for a processing station according to GE Fig. 5 with a can body on which the upper end element is inserted,

Fig. 9a

a section through a constriction device with two situations at the beginning of a constriction process,

Fig. 9b

a section through a constriction device with two further situations during the constriction process,

Fig. 9c

a section through a constriction device with two situations at the end of the constriction process,

Fig. 9d

a schematic plan view of a constriction device according to Fig. 9a .

Fig. 10a

a section through a can body of an aerosol can with inserted bottom and attached valve seat,

Fig. 10b

a side view of a can body with a special appearance,

Fig. 11a

a section through a tube with inserted threaded part,

Fig. 11b

a section through a tube with attached threaded part,

Fig. 12

a section through the upper end of an aerosol can with a novel valve adapter,

Fig. 13

a section through the upper end of an aerosol can with two different valve seats, and

Fig. 14

a section through the lower end of a can body with a bottom cover.

Fig. 15a

a vertical section through a can jacket with bulges at both end faces,

Fig. 15b

a vertical section through a can body with bulges on the can jacket and firmly welded end elements,

Fig. 16

a vertical section through an aerosol can with an upper end element with valve,

Fig. 17

a part of a vertical section through an aerosol can with an upper end element with valve,

Fig. 18a

a schematic plan view of a separator which cuts strips of sheets,

Fig. 18b

a schematic side view of a device for applying foils on both sides of the strip,

Fig. 18c

a schematic plan view of a plant part of cuts from strip sections and this transforms into flattened can coats,

Fig. 18d

two schematic cross-sections of processing steps for forming sections in the flattened can jacket mold,

Fig. 19

a schematic side view of a plant, the band-shaped flat material coated on both sides with films and the strip material continuously brings in a flattened can jacket shape,

Fig. 19a

a plan view of the sheet after attaching incisions,

Fig. 19b

a schematic cross section in the region of forming elements for forming the strip material in the flattened can jacket shape,

Fig. 20

a cross section of the flattened can jacket shape,

Fig. 21

a schematic sectional view of the step for applying a masking tape,

Fig. 22

a schematic cross section of an apparatus for laser welding the can longitudinal seam,

Fig. 23

an enlarged section Fig. 5 .

Fig. 24

a schematic side view of a plant part for laser welding of the longitudinal seam, pressing the cover strip, cutting and conditioning of closed can jacket sections,

Fig. 25

a cross section through a device for pressing the cover strip,

FIG. 1 shows a system for producing can bodies, in which a metal strip 1 is supplied from a metal strip supply roll 2 via a deflecting device, for example a first guide roller 3, in the direction of a processing axis different processing stations for producing a tube formed by forming and welding. Optionally, the metal strip 1 is preheated with an induction heater 4. Following the induction heating 4, if necessary, a first film strip 5 is placed on the metal strip 1 from a first film supply roll 6 via a deflection device, for example a second deflection roller 7, in the direction of the machining axis. The second deflection roller 7 can press the first foil strip 5 onto the preheated metal strip 1, so that a sealing layer of the first foil strip 5 sealing at the present temperature connects the foil strip 5 to the metal strip 1. The first film strip 5 is to form an inner barrier or inner protective layer 5 'on the resulting tube. To form a closed tube, a welding connection between the two lateral edges of the metal strip 1 is necessary. Because the foil strip 5 does not endure the temperature arising in the region of the weld seam, the foil strip 5 will optionally not extend laterally as far as the edges of the metal strip 1. In order to still be able to form a closed inner barrier, a seam covering tape 8 is placed on the first film strip 5. For this purpose, the seam covering tape 8 passes from a cover strip supply roll 9 via a deflection device, for example a second deflection roller 7, into

Direction of the machining axis on the first foil strip 1. The sealing layer of the seam covering strip 8 is directed upward. The seam covering tape 8 should adhere only temporarily to the first film strip 5.

Fig. 2a shows the metal strip 1 with the associated foil strip 5 and the applied seam covering tape 8 in the cutting area A according to Fig. 1 , The arrows 10 indicate the subsequent forming process. In accordance with Fig. 2b A tube 11 is formed around the lateral edge regions of the metal strip 1 around the longitudinal axis and fed to one another. In order to join the adjoining lateral edges 1a, 1b of the metal strip 1, a weld seam 11a is formed in a welding step with a welding operation 12. A film-free area 11b should be covered by the weld seaming tape 8 after welding.

According to Fig. 1 is a forming device 13 is provided for the forming process, in which the metal strip 1 is preferably formed by means of rollers to the tube 11. In order to carry out the welding operation 12, the lateral edges of holding rollers 14 are pressed against each other without a gap while a welding device 12a carries out the welding operation 12. In the film-free area 11b, this results in the weld seam 11a. Preferably, a laser welding device is used, but if necessary, a conventional welding device known in the conventional production of three-part can bodies is used. In section B, the tube 11 has approximately the shape according to Fig. 2b , In the manufacture of cans which do not require an inner barrier or inner protective layer 5 ', the feeding of a foil strip 5 and a seam covering strip 8 can be dispensed with.

For the intended continuous production of the tube 11, the deformed metal strip 1 must be conveyed continuously. For this purpose, for example, two counter-rotating conveyor caterpillars 15 are provided which press from opposite sides against the tube 11 and take the pipe 11 frictionally. Because the seam-covering tape 8 has to reach the film-free area 11b, the pipe 11 is compressed at least in the area of the seam-covering tape 8. This compression is optionally achieved in part by the conveyor 15. In order to achieve a desired shape when compressed in section C, is in accordance with Fig. 2c at least a pair of flat roller 16a provided. So that two lateral folding areas 11 c receive a defined shape, it may be expedient to associate the two flat pressing rollers 16 a with lateral forming rollers 16 b. By the rollers 16a and 16b in pairs opposite each other Press against the tube 11, the tube 11 can be formed into a desired cross-sectional shape.

Fig. 2d shows how the Nahtabdeckband 8 is pressed by the compression of the tube 11 in the film-free area 11b to the inner protective layer 5 '. If the seam covering tape 8 has a sealing layer on the side lying against the inner protective layer 5 'and the foils-free region 11b, then a heat-sealing connection to the inner protective layer 5' and optionally to the foil-free region 11b can be formed. As a result, a continuous protective barrier is formed in the circumferential direction of the tube. The heat required for the sealing can be supplied via the flat pressing rollers 16a or via an induction heater 4 arranged in the region of the two flat pressing rollers 16a.

The heating of the tube 11 or its metal layer 1 'with the induction heater 4 can also be used for the fixed application of an outer film layer 17'. In this case, if necessary, subsequently to the induction heating 4, a second film strip 17 is brought from a second film supply roll 18 via a deflection device, for example a third deflection roller 19, in the direction of the processing axis onto the outside of the tube 11. For this purpose, a camming device, not shown, is used, which surrounds the lateral edges of the second film strip 17 around the tube 11 so that the edges are connected to one another in an overlapping region 17a.

Fig. 3a shows the section D with two on both sides of the flattened tube portion arranged press rollers 20. The press rollers 20 press the film edges in the overlapping region 17a together. If the second film strip 17 now comprises a sealing layer on the side facing the tube 11, a sealing connection can be achieved in the overlapping region 17a. In the FIGS. 3a and 3b the inner protective layer 5 'is not shown, but only the metal layer 1'. In order to ensure a wrinkle-free contact of the outer film layer 17 'on the metal layer 1', the outer film layer 17 'is connected in the overlapping region 17a, that the circumference of the outer film layer 17' is slightly smaller than the circumference of the tube 11 and the Metal layer 1 '. This is easily achieved due to the flattened shape of the tube 11 with the open edge areas.

In section E is a pressing device according to Fig. 3b and 3c provided with at least two first pressure rollers 21 and optionally two second pressure rollers 22. The two first pressure rollers 21 are arranged on both sides of the flattened tube region, and press the outer film layer 17 'close to the metal layer 1'. The two second pressing rollers 21 are arranged on both sides of the curved pipe region. To ensure a wrinkle-free concerns, preferably pressing rollers 21, 22 with a slightly elastic coating 21a, or 22a, provided. It goes without saying that the outer film layer 17 'can also be omitted. The system for producing can bodies can be used for can bodies with or without foil layers. It would also be possible on a can body, which is produced by the new method, to apply a decorative film according to a known method. However, the continuous application of a film strip to a pipe is easier.

In order to separate portions of the length of a desired can height from the tube 11, a separator 23 is provided. The separation device 23 should, if possible, perform a chip-free separation step. Because the pipe sections or can shells 24 do not have to have a defined shape after the separation step, preferably a cutting operation is carried out with a cutting edge 25 and a base 26 cooperating with the cutting edge 25. Due to the substantially flat pressed tube 11, the required stroke for the cutting movement shown by the arrows 25a is small. The small stroke enables a quick cutting process. The cutting edge 25 is optionally moved when cutting with the resulting tube 11 in the direction of the tube axis and reset after the separation of a pipe section 24, which is illustrated by the arrows 27. Because the cutting process is very fast, the tube feed is small during this short time. Therefore, solutions with a fixedly positioned in the direction of the tube axis cutting edge 25 can be provided. It must then only be ensured that the tube 11 can bend in a bending region due to the fixation at the cutting edge 25 so that the retained feed is taken as a bending extension in the bending region. After cutting, the deflection is compensated by a slightly increased feed rate of the pipe end in the separator 23. If the pipe end or the end of the separated can jacket 24 is completely flattened by the cutting process, so does not bother.

If a foil strip 5, 17 and possibly a seam covering tape 8 is arranged on the metal strip 1, a pipe 11 with a metal layer 1 'and at least one film layer 5', 17 'is formed. If, according to the prior art, a film piece is fed to a can jacket, the film piece must be separated from a film supply roll and placed individually on the can jacket 24. Cutting and placing thin films is very difficult. The inventive solution with the continuous application of the film strip 5 and the cutting of the film together with the metal layer 1 'leads to a much simpler film coating. The cutting of the metal layer 1 'together with the film is easier because the total thickness of the metal layer 1' and at least one film layer 1 ', 17' is sufficiently large for a simple cutting process.

The cut and substantially flat can shells 24 can now be formed directly afterwards or after an intermediate storage or transport to can bodies. Due to the flat state, the volume required for storage or transport per can jacket 24 is small.

According to Fig. 1 During further processing, the flattened can jacket 24 is pushed open with at least one impact tool 28 of a jacket molding device. In the embodiment shown schematically, impingement tools 28 with insertion edges 28 a are introduced into the can jacket 24 from both open end faces of the can jacket 24. Optionally, the desired cross-sectional shape is achieved directly at the eructation. Preferably, however, a widening tool 29 is used in a further step, which increases the circumference of the can jacket 24 and in particular at one, preferably at the lower, can end forms a cross-sectional constriction of the expanded to a smaller cross-section.

Fig. 4 shows the expansion process in two steps. After insertion of an adapted to the cross section of the can jacket 24 Einführstirn 29a in the can jacket 24 at a first end face 24a, the expansion tool 29 is moved with a widening portion 29b with a larger cross section through the can jacket 24 until it reaches an end position at a second end face 24b of the can jacket 24 reached. The widening region 29b is shaped such that the can jacket 24 receives a desired constriction 24c at the second end face 24b, in particular with a constriction radius usual in the case of aerosol cans.

In order to obtain a can body 30 which is ready for filling, the can jacket 24 must be provided with a closure element at least on one end face 24a, 24b. At cans, at least one can bottom 31b is sealed to the can shell 24. In the case of tubes, a tube end part 32 is fixed with a thread 32 b arranged around an outlet opening 32 a. Because more cans than tubes are made and a generic term, such as containers, is confusing, the term can is understood here to mean that tubes are also included. According to Fig. 1 and 5 For example, in a transfer step 33, the end elements 31b, 32 are transferred from a storage area 34 of an insert holder 35. The insert holder brings the end elements 31b, 32 to the desired connection point of the can jacket 24. In a welded connection, a welding device 37 generates a weld seam when rotating the can jacket 24 by means of a rotary holder 36. It goes without saying that in addition to the welding process, in particular laser welding, Also mechanical connection methods, such as crimping or folding can be used. Optionally, the end element 31b, 32 is adhesively bonded to the can jacket 24 with an adhesive bond.

Fig. 5 shows a processing station in the form of a turntable 38, the can coats 24 pass over a transfer plate 39 on the turntable 38 and the can body 24 'are brought via a further transfer plate 39 away from the turntable 38 to a continuation.

Fig. 6a and 6b show the light guide 40 with which the welding beam is supplied to the processing points of the turntable 38. The rotary holders 36 are arranged on against the can coats 24 pressable arms 41. The Einsetzhalterungen 35 are preferably connected to rotary actuators to achieve closed when welding seams can.

Fig. 7 shows a detailed view of the most important elements of a processing station for setting a first end member 31b, 32 on the can jacket 24. When the bottom of the can 31b is pressed from the can interior to the constriction 24c, can with the welder 37 from the side not visible connection seam 42 generates become. In order to position the can bottom 31b without a large lifting movement, it is optionally pressed from the outside to the constriction 24c. For pressing the arms 41 and the rotary holder 36 are connected to the Einsetzhalterungen 35. The connection is made via connecting rods 43 with not shown pressing and releasing devices. The can bottom 31b is adapted in the outer edge region to the constriction 24c and has in the central region a curvature against the can interior towards.

According to Fig. 8 At a can body 24 'with can jacket 24 and inserted can bottom 31b an upper end element 31a with the valve seat (valve adapter) fixed. It goes without saying that the upper end element may also comprise another type of opening, for example a threaded neck, instead of the valve seat. The device for setting the upper end element substantially corresponds to the device according to Fig. 7 wherein the can body 24 'is held by a can holder 44 and rotated, and the swivel holder 36 is fitted to the upper end member 31a. The first end face 24a facing away from the bottom 31b of the can is narrowed so that a first neck region 24a 'with decreasing cross section is formed. The circumference of the upper end member 31a is smaller than the circumference of the can body 24 'in the cylindrical portion. In addition, because it is possible to dispense with a fold region for forming a crimping or folding connection, the proportion of material of the upper end element 31a is correspondingly smaller in comparison with the known solutions. The connecting seam 42 ensures a firm and tight connection between the first neck region 24a 'and the upper closure element 31a, which forms a second neck region adapted to the first in the outer edge region.

For narrowing the open end of a can body 24 ', a known necking process such as neck-necking or spin-flow necking may be performed. Preferably, however, as in the FIGS. 9a-d illustrated a method performed in which a can body 24 'to be narrowed, which extends along a longitudinal axis 24d and in the area to be narrowed circular cross-sections, is held in two areas. In the first region, the can body 24 'is held firmly by a first holder 45, so that it can be set in rotation by the first holder 45 about its longitudinal axis 24d. For holding an annular clamping element 45a is optionally provided, which is in particular to bring pneumatically in clamping and release position. But it can also be a mechanical clamping arrangement, for example, with at least three evenly distributed around the circumference clamping elements 45a, are provided. The second area is located at the can end to be narrowed or at the first end face 24a. There is the can body 24 'held by a co-rotating second holder, which comprises a longitudinally relative to the can body 24' and the first holder 45 adjustable bearing member 46. The adjustable bearing part 46 is inserted into the can body 24 'in the form of a cone and, at the end directed against the can interior, has an annular deflecting edge 46a, the outer diameter of which is adapted to the inner diameter of the first end face 24a.

The desired constriction is achieved with at least one deformation surface 47a, which adjoins the deflecting edge 46a in the axial direction with a small distance and can be radially pressed against the inside, wherein a free space 48 is provided inside the can inside radially within the deformation surface 46a, so that a deformation of the can jacket 24 or the can wall against the inside is nothing contrary. Optionally, a projecting from the bearing member 46 into the can interior support pin is provided, the diameter of which is adapted to the maximum constriction, so that the narrowed end face is stored after narrowing of this pin. The deformation surface 47a is preferably formed by the outer surface of a forming roller 47. For the narrowing, an optimal interaction of the deflection edge 46a with the deformation surface 47a is important. For this purpose, the radii of curvature R1, R2 of the mutually facing curvatures of the deflection edge 46a and the deformation surface 47a are matched to one another. According to an analogy to thermoforming processes, in which the can wall is drawn around two annular edges, the radius of curvature R1 corresponds to the hold-down radius and R2 to the draw radius. The gap s between the deflection edge 46a and the deformation surface 47a in the direction of the can axis 24d is matched to the thickness of the can wall and remains substantially constant during the constriction. The at least one forming roller 47 is in the axial direction in a substantially fixed position relative to the bearing part 46. The at least one forming roller 47 is moved axially together with the bearing part 46 relative to the first holder 45.

According to Fig. 9d in the circumferential direction of the can body 24 'preferably three forming rollers 47 are arranged uniformly spaced, which can be pressed together radially inwardly to a minimum can circumference 49. It goes without saying that two or more than three forming rollers 47 can be arranged. If only one forming roller 47 is provided, the deformation forces that occur are one-sided, which is particularly problematic towards the end of the deformation.

The Figures 9a 9b and 9c show a continuous narrowing of five situations V0, V1, V2, V3, V4 with increasingly narrow open can end. At the beginning of the narrowing V0 the forming rollers 47 are spaced in the axial direction by a distance a from the first end face. The bearing part 46 extends into the can interior over an extension of the initial distance a minus the gap s. Once a small constriction ring is formed, such as shown in the situation V1, the can jacket 24 receives increased stability against asymmetric or undesirable deformations. With increasing constriction, as can be seen in the situation V2, the first end face 24a is pulled more and more against the deflection edge 46a until, according to V3, it is no longer held only in the gap s and according to V4. An end region at the first end face 24a is optionally formed with a pressing process subsequent to the constriction. An advantageous deformation is in the FIG. 12 shown.

The method described and the system described enables the efficient production of various can bodies and also tubes. Fig. 10a shows an aerosol can 24 'in which at the narrowed second end face 24b of the can jacket 24, a can bottom 31b is fixed by means of laser welding. In the first end face 24a, an upper end element 31a with valve seat 50 is fixed by means of laser welding. The can bottom 31b and the upper end element 31a can each be made independently of the can jacket 24. These separately manufactured parts may have different material thicknesses and / or material compositions optimized for the particular function. In a separately manufactured upper end member 31a, a high quality valve seat 50 can be ensured.

Fig. 10b shows an embodiment in which the can jacket 24 is specially designed with a stamping process. Because the material of the can jacket 24 of a can body according to the invention is not hardened by the ironing process, the known embossing processes can be used without problems.

Fig. 11a and 11b show can body 24 'or tubes with a fixed to the can jacket 24 from inside or outside tube termination part 32 which has a thread 32 b for an outlet, not shown, around an outlet opening 32 a.

Fig. 12 shows a section of an upper end element 31a which is connected via a weld seam 42, preferably a laser weld, with a can jacket 24. The can jacket 24 has, for example, at least one inner coating 5 'and is folded outwards on the first end face 24a. The upper end element 31a comprises a metallic inner part 51 and a plastic region 52, which surrounds the inner part 51 in a bead shape, at least in the case of the valve seat 50. The metal part makes possible the weld seam 42. If the plastic region 52 bears tightly against the inner coating 5 ', it may be possible to prevent the contents of the can body from coming into contact with a metallic layer.

According to Fig. 13 For example, the plastic portion 52 permits insertion of a valve 53 without the need for a seal 54 as required by the prior art. The plastic portion 52 has a thickened end edge to which a valve connection portion can be clamped. The clamping tongs 54 can press the connection edge of the valve 53 tightly against the plastic region 52. Since the metallic inner part 51 does not have to be bent over by 270 °, the production of the part 31a is greatly simplified. The metallic inner part 51 can be provided with the plastic region 52 with an injection molding step. This two-component end member 31a is also novel and inventive regardless of the described can manufacturing process.

Fig. 14 shows the lower end portion of a can body 24 ', in which the can bottom 31b is fixed with a weld 42 on the second end face 24b. To cover the weld 42 and the inserted can bottom 31b, a bottom cover 55 is used. The bottom cover is preferably made of plastic and is sealed about the bottom of the can 31 b. Optionally, the second end face 24b is formed, or arranged on the bottom of the can 31b, that the bottom cover 55 can be fixed in a clamping fit. In the illustrated embodiment, the outer edge portion of the can bottom 31b is folded over to facilitate stacking from a can bottom stack. The edge of the can bottom 31b could also be folded down to prevent the metallic edge surface 56 of the can bottom 31b from coming into contact with the can contents in an inner coating.

Fig. 15a shows a can jacket 24 with annular bulges 60, which are formed at both end faces 24a and 24b radially outward. Both Bulges formed against the respective end face 24a, 24b towards a cross-sectional constriction. To form the bulges 60, for example, two matching shaping rollers 61a and 61b are arranged on the inside and outside of the can jacket 24. As the can jacket 24 is rotated past the forming rollers 61a and 61b, the inner forming roller 61a can be pressed radially outwardly against the outer forming roller 61b until the desired bulge 60 is formed. With a bulge 60, a shoulder 60a is provided on at least one end face 24a, 24b of the can jacket 24 without a narrowing step. Expansions are much easier to produce with good quality compared to constrictions. With little effort, a shoulder 60a is achieved with a smooth surface.

According to Fig. 15b At the bulges 60 on the shoulders 60a, end elements, for example a can bottom 31b or an upper end element 31a, are pressed. With a connection seam 42 in the form of a laser weld seam, a firm and tight connection is formed. Preferably, first, the bottom of the can 31b is firmly welded. Before or optionally after the welding of the upper end element 31a, the can jacket 24 can still be deformed, for example, in which the can cross-section is widened at least to the diameter of the at least one bulge 60. Prior to the welding of the upper end element 31a, 24 can be introduced into the inside of the can for expanding the can jacket 24 molding tools, such as rollers. Optionally, a fluid is introduced under pressure into the can interior to expand the can cross-section and pressed the can jacket 24 in an inner mold.

Fig. 16 shows an aerosol can 24 'made using a cylindrical can jacket 24 with protrusions 60. On a lower shoulder 60a, a can bottom 31b was placed. The outer edge region of the can bottom 31b is adapted to the shoulder 60a, so that the outer edge of the can bottom 31b when pressed tight against the shoulder 60a and thus a precise and dense laser weld seam can be formed as a connecting seam 42. The can jacket 24 is widened from a first cylindrical shape into a second shape before the upper terminating element 31a is put on. In this case, for example, desired surface structures can be achieved. To expand the can jacket 24 optionally mold tools, such as rollers, are introduced into the can interior. Preferably, however, a fluid is introduced under pressure into the can interior to expand the can cross-section and the can jacket in pressed an inner mold, which, for example, from the patents EP 853 513 B1 . EP 853 514 B1 and EP 853 515 B1 is known. The bulge 60 on the upper end face 24a is preferably left in the original shape, so that a dome-shaped upper end element 31a can be pressed against the shoulder 60a and welded to a connecting seam 42.

The upper end member 31a comprises a valve 62 from which a hose 63 leads against the can bottom 31b and which can be actuated via a discharge tube 62a. A discharge part 65 inserted on the discharge tube 62a is held in a cap 66. To actuate the valve 62, an operating portion 66a of the cap 66 is pressed onto the discharge part 65. In this case, the discharge tube 62a is pressed down and thus the valve 62 is opened. The cap 66 is held with a latching portion 66 b in a corresponding latching shape of the can jacket 24. The latching shape of the can jacket 24 is optionally formed by the bulge 60 or a narrowed area between the bulge 60 and the expanded portion of the can jacket 24. Optionally, the latching form can also be formed by the outer edge of the upper end element 31a or by the connecting seam 42.

The cap 66 covers the upper closing element 31a and, together with the can jacket 24, which preferably comprises a decorative film, ensures an attractive appearance which corresponds to that of a one-piece aluminum can. Embodiments are also possible in which can jacket 24 and can bottom are integrally formed, or in which the connecting seam 42 between can jacket 24 and can bottom 31 b are covered by a bottom cover. Even if the connecting seam 42 is visible at the bottom of the can, it is hardly recognizable as a thin laser weld seam. In order to prevent oxidation of the connecting seam 42, it is optionally sealed with a coating.

In order to ensure a continuous inner coating even inside the can, the can jacket 24, the can bottom 31b and the upper end element are provided on the inside with a protective layer, in the form of a film or a coating. In the case of the connecting seams 42, sealing material 67 is optionally arranged annularly, which ensures a continuous sealing layer even after the formation of the connecting seams 42. So that the laser welding is not disturbed by coatings, which can together adjoining parts in the area of the laser seam are treated before the laser welding with a laser to remove the coating. The inner coating is not affected.

Fig. 17 shows the upper part of an aerosol can 24 ', in which the can jacket 24 is connected at a narrowed end face 24a with a dome-shaped upper end member 31a via the connecting seam 42. If necessary, the can jacket 24 is widened from a first cylindrical shape into a second shape before the upper terminating element 31a is put on. In this case, for example, desired surface structures can be achieved. The closing element 31a comprises a valve 62 from which a hose 63 leads to the bottom of the can and which can be actuated via a discharge tube 62a. The spray head 64 placed on the discharge tube 62a includes a discharge channel 64a and a shell 64b. The sheath 64b extends radially outwardly and axially against the upper end element 31a preferably so far that the connecting seam 42 is substantially covered and thus the upper end element 31a is not visible. The aerosol can 24 'appears only with the can jacket that includes a decorative layer and with the spray head 64.

Regardless of the exact design of the welded parts, the welding of an upper end member 31a with the valve 62 is very advantageous. By hard welding of the upper end element 31a micro-leaks are excluded. The filling of the aerosol can 24 'takes place before the placement of the spray head 64 through discharge tube 62a.

FIG. 18a shows a separator 101 in the form of a bilaterally mounted rotatable shaft with separators 102. The separators 102 can be positioned at mutual distances associated with the desired can circumference. Now, when sheet metal plates are passed through the separator 101, so arise strips 103 with the width in the range of the can circumference and the length of at least one dose coat height.

Fig. 18b shows a device part for applying foils on both sides of the strips 103. The strips 103 are moved substantially directly adjacent to each other along a processing axis. About the strip 103, a roller 104 is disposed with an inner film 105 and under the strip 103 a roller 104 with the Decorative film 106. The strips 103 are heated by a heating device 107 to a temperature necessary for sealing the films 105, 106. Two pressing rollers 108 and one sealing layer on the films 105 and 106 ensure a firm connection of the films 105 and 106 with the strips 103. In order to be able to treat the coated strips separately further, a film separating device 109 is provided which separates the films 105 and 106 between the strips 103 mechanically or optionally with heat separates.

Fig. 18c shows a part of the plant which cuts from strips 103 with a separator 101 sections 110 and transforms them in a first forming device 111a in flattened can coats 112.

In the execution according to Fig. 20 the flattened can jacket 112 has a depression 112a in the region of the center line, two flat central regions 112b on both sides, then a respective curved region 112c and two flat edge regions 112d which can be pressed onto the flat central regions 112b. In the pressed-together end faces 112e, the can jacket is closed by means of laser welding.

According to Fig. 21 In the region of the depression 112a of the flattened can jacket 112, a masking tape 113 is arranged. The cover tape 113 is placed on the inner film 105 by a feed device 114, preferably directly after or with the feeding of the inner film 105.

Fig. 19 shows an embodiment in which the flattened can coats 112 continuously formed as a strip material and then welded, so that the separation of individual can coats 112 takes place only at the end. From a flat roll 115, strip-shaped flat material 116 is fed via a feed device 117 to a cutting device 118. The cutting device 118 forms on the strip-shaped flat material perpendicular to the belt axis two cuts 118e. When forming in the flattened shell form these cuts 118e get into the two curvature regions 112c, so that the separation of the flat material is only necessary in the flat area between the radii of curvature when separating the can shell sections. If the separation also had to be carried out in the areas of curvature, wrinkles would result in wrinkles which could no longer be completely smoothed out.

In the subsequent device part foils are mounted on both sides of the sheet 116. The band-shaped flat material 116 is moved along a processing axis. A roll 104 with an inner foil 105 is arranged above the flat material 116, and a roll 104 with the decorative foil 106 is arranged underneath the flat material 116. The flat material 116 is heated with a heating device 107 to a temperature necessary for sealing the foils 105, 106. Two pressure rollers 108 and one sealing layer each on the films 105 and 106 ensure a firm connection of the films 105 and 106 with the flat material 116.

The both sides coated flat material 116 is formed in a second Umformvorrichtung 111b transversely to the belt axis continuously in a flattened closed mold, which in cross section of the embodiment according to Fig. 20 equivalent. By way of example, the second forming device 111b comprises successively pairs of rolls which more and more fold over the lateral edge regions of the flat material 116 towards the center. Fig. 19b shows an example of a pair of rollers 119. Before folding the lateral edge region, the recess 112a is formed in the center of the sheet 116 by means of a cooperating pair of forming rollers.

According to Fig. 18d is formed by the first forming device flat material in the form of sections by means of a forming mold 120 and a corresponding first forming tool 121 U-shaped, with the recess 112 a. By means of two acting from the side further forming tools 122, the lateral edge regions completely folded. In order to press the middle area flat, is pressed again with a first forming tool, not shown, without recess projection and with a smaller width on the shell portion.

The laser welding of the can longitudinal seam is carried out on the flattened can jacket band substantially the same as on the individual can coats. The individual can coats are preferably fed directly adjacent to each other fed to a welding device, so that the welding device can form the weld seam substantially continuously as in a can jacket band.

FIGS. 22 and 23 show a first welding device 123 for laser welding the can longitudinal seam 124 at the pressed together end faces 112e of a flattened can jacket 112. The lateral to be joined together Edge regions 125 of the flat material lie on either side of the depression 112a, depending on a flat central region of the inner boundary of the can jacket which acts as a guide partial surface 112b. In the illustrated embodiment, the two guide part surfaces 112b are formed on the inside of the can jacket.

The can jacket 112 has a closed flattened shape, wherein the abutting planar partial surfaces are connected to each other during the welding over curved areas 112c. An edge region 125 is pressed by one of the two lateral pressure rollers 126 by means of a pressing device 127 against the other edge region 125, whereby the compression of the end faces 112a is ensured. In order that the two edge regions 125 pressed on a common abutment can be held on guide partial surfaces 112b, retaining rollers 128 are arranged such that they hold the two edge regions 125 at the end faces 112e on the guide surfaces 112b. One of the two holding rollers 128 is pressed by a pressing device 127 against the one edge region 125. The flattened can jacket 112 is supported by a support roller 132 in the region of the support rollers 128. The other retaining roller 128 is held by an adjusting device at an adjustable distance from the other edge region 125. The welding is achieved with a laser beam 130 from a laser source 131.

In order to prevent impairment of the decorative film 106 when welding the longitudinal seam 124, the decorative film 106 can be arranged on the flat material 116, 103 such that it does not extend to the end surface 112e at one edge region 125 and over the end surface 112e at the other edge region 125 protrudes. The protruding film region 106a is not firmly sealed in an edge region of the flat material 116, 103, so that this free film edge 106a can be transferred away from the region of the longitudinal seam 124 before the longitudinal seam 124 is formed. After the welding process, the free film edge 106a according to Fig. 25 placed over the longitudinal seam 124 and sealed tight. As a result, the longitudinal seam 124 is completely covered outside.

A damaged inside the weld 124 inner liner 105 is covered by the cover 113, so that a complete corrosion protection is guaranteed. During the welding process, a small free space 129 between the end faces 112e and the cover tape 113 ensures that this is not impaired during welding. After the welding process, the depression 112 a pressed with the cover 113 against the weld 124 and there are set so tight that it is firmly sealed on both sides of the intact inner liner 105. Because the masking tape on the side facing the inner film 105 in the recess 112 a does not comprise a sealing layer, it can be transferred to the inner film 105 in the longitudinal seam 124.

Fig. 24 shows in addition to the retaining roller 128 and the support roller 132 guide means 133. The in Fig. 25 shown solid sealing of the above film portion 106a and the cover 113 is achieved with two press rollers 134. The heat required for sealing is optionally from the longitudinal seam 124, or is supplied from the outside. In a system with a can jacket tape, the can jacket sections are severed in a severing device 135, preferably with circumferential cutting edges. The closed flattened can coats 112 'reach, for example, the top of a conditioning device 136, where they are kept warm for a given dwell time by means of supplied hot air 137 as long as necessary for a permanent connection between the metallic sheet and the decorative film 106 and the inner film 105 is. The closed bottom flattened can jackets 112 'discharged directly, after storage or after transport, can be used to make can bodies.

Claims (25)

1. A method for producing a can body (24') in which method a closed can shell (24) is established by a welding seam (11a), that extends over the entire height of said can shell (24), and a closure element (31b, 32, 31a) is arranged on said can shell (24), wherein, starting from a metal band (1), a tube (11), closed in circumferential direction, is formed by at least one deformation step and a welding step, and a welding seam (11a, 124) is substantially continuously welded in the tube's longitudinal direction during the welding step, tube sections from the emerging tube (11) with the length of a desired can height being further treated as can shells (24), characterised in that said welding seam (11a, 124) is formed as a butt-joint or jump joint in the tube's longitudinal direction, a restriction (24c, 60a) is formed at a lower front side (24b) of said can shell (24), the can bottom (31b), having a correspondingly formed fringe area, is pressed against said restriction of said can shell (24), and is firmly connected to said can shell (24) in said area of said restriction (24c, 60a) by circumferential welding.
2. Method according to claim 1, characterised in that, for forming the tube (11), the metal band (1, 116) in its longitudinal direction is passed through deformation means (13, 111b) and past welding means (37, 123), wherein said deformation means (13, 111b) deforms said metal band (1) continuously so that the two side edges (1a, 1b, 112e) are pressed butt-jointed together, and the two lateral edge areas (112d, 125) to be interconnected lie at both sides of a depression (112a) each on a flat central area of the metal band (1, 116), which acts as a partial surface of guidance (112b), wherein the welding means (131) interconnects the front surfaces (112e) by means of laser welding and the depression (112a) provides a free space (129) at the welding seam (124).
3. Method according to claim 1 or 2, characterised in that the can bottom (31b) is pressed from the can's interior against the restriction (24c, 60a) of the can shell (24) formed towards the front side (24b), and circumferential welding is formed as a laser welding seam.
4. Method according to claim 1 or 2, characterised in that the can bottom (31b) is pressed from the exterior against the restriction (24c, 60a) of the can shell (24) formed towards the front side (24b), and circumferential welding is formed as a laser welding seam.
5. Method according to any of claims 1 to 4, characterised in that a decorative foil (17') is applied to the outer side of the metal band (1) after, or optionally prior to, deforming and welding, preferably by supplying a foil band (17).
6. Method according to any of claims 1 to 5, characterised in that a first foil band (5) is laid in longitudinal direction of the metal band (1) onto the flat metal band (1) and is fixed by means of a sealing connection to form an inner protective layer (5'), a seam covering band (8) being optionally laid onto said foil band (5) and is applied to the area of the welding seam (11a) after said welding step.
7. Method according to any of claims 1 to 6, characterised in that, to sever tube sections, severing means are moved together with the emerging tube (11) during the welding procedure, and are returned after severing a tube section.
8. Method according to any of claims 1 to 7, characterised in that can shells (24) are deformed by shell forming means (28, 29) in such a manner, that a circular cylindrical cross-sectional shape is achieved, wherein an expanding step is carried out which increases the circumference of said can shell (24) and, in particular, forms a cross-sectional restriction from the expanded cross-section to a smaller one at one can end (24b), particularly at the lower one, wherein said cross-sectional restriction (24c) is optionally formed with a radius of curvature, which corresponds to the current shape on aerosol cans at the transition from the can wall to the can bottom (31b).
9. Method according to any of claims 1 to 7, characterised in that at least at one front side of a circular cylindrical can shell (24), an annular bulge (60) is formed radial to the outside, wherein the can shell (24) has a cross-sectional contraction at the bulge towards the front side.
10. Method according to any of claims 1 to 9, characterised in that at least one restriction step is carried out at an upper front side (24a) of the can shell (24).
11. Method according to claim 10, characterised in that subsequently to restricting, a valve seat is formed at the upper restricted end.
12. Method according to claim 10, characterised in that subsequently to restricting, a closure element (31a), including a valve seat at the upper restricted end, is sealingly connected to the can shell (24), optionally by a folded seam connection, but preferably by a welding connection, particularly a laser welding connection.
13. Method according to any of claims 10 to 12, characterised in that during at least one restriction step, the can body to be restricted (24') is held in two areas, wherein the can body (24') is firmly held in the first area by a first holding means (45) so that it may be rotated about its longitudinal axis (24d) by said first holding means (45), while the second area is situated at the can end to be restricted, where the can body (24') is held by a co-rotating second holding means, which comprises a bearing part (46) displaceable in longitudinal direction relative to said can body and having an annular deviation edge (46a) formed at that end, which is directed towards the can's interior, and deformation is achieved by at least one deformation surface (47a), which in axial direction joins the deviation edge (46a) at a distance (a) and is able to be pressed in radial direction against the interior, a free space (48) being provided in the can's interior in radial direction within the deformation surface (47a) so that there is nothing which opposes deformation of the can shell (24).
14. Method according to claim 10, characterised in that an annular bulge (60) is formed radial to the exterior each on the two front sides (24a, 24b), the can shell presents a cross-sectional contraction at the bulges (60) towards the respective front side (24a, 24b), while the can bottom (31b) is welded to one front side (24b) and an upper closure element (31a) is welded to the other front side (24a).
15. Method according to any of claims 1 to 14, characterised in that a bottom cover (55) is inserted in such a manner that the interconnection of the can shell (24) and the can bottom (31b) is covered by it.
16. Method according to any of claims 1 to 15, characterised in that an upper closure element (31a) including a valve (62) is attached to the can shell (24) by means of laser welding.
17. Device for producing a can body (24') comprising means for sealingly interconnecting a can shell (24), closed by a welding seam (11a, 11b), to a closure element (31b, 32, 31a) able to be fixed at the front side to said can shell (24), the device comprising a supply arrangement for supplying a metal band (1), at least one deformation means (13) for deforming said metal band (1) into the shape of a closed tube (11), welding means (37) for substantially continuously welding the shaped tube (11), and a severing device (25), which enables severing closed can shells from said tube (11), characterised in that said deformation means (13) comprises shaping rolls (119) for deforming said metal band (1) into the shape of a closed tube (11), said welding means (37) comprises press rolls (126) for compressing the edge areas (125) of said metal band (1) to be welded together, as well as a source of laser (131) for providing a laser beam (130) by which the welding seam (11a, 124) is formed as a butt-joint or jump joint in the tube's longitudinal direction, and that said means for sealingly interconnecting a closed can shell (24) to said closure element (31b, 32, 31a) comprises forming means (29b, 61a, 61b), holding means (35, 36) and welding means (37), wherein said forming means (29b, 61a, 61b) forms a restriction (24c, 60a) at the lower front side (24b) of said can shell (24), said holding means (35, 36) presses said can bottom (31b), having a correspondingly shaped fringe area, against said restriction (24c) of said can shell (24), and said welding means (37) connects said can shell (24) within the area of said restriction firmly to said can bottom (31b) by circumferentially welding in the form of laser welding.
18. Device according to claim 17, characterised in that said deformation means (13) deforms said metal band (1) continuously around an axis, which extends parallel to said metal band (1), in such a manner, that the two side edges (1a, 1b) contact each other, and the two lateral edge areas (112d, 125) to be interconnected lie at both sides of a depression (112a) each on a flat central area of the metal band (1, 116), which acts as a partial surface of guidance (112b), and the welding means (131) interconnects the front surfaces (112e) by means of laser welding, wherein the depression (112a) provides a free space (129) at the welding seam (124).
19. Device according to claim 17 or 18, characterised in that said severing device comprises severing means, which are moved together with the emerging tube (11) during the welding procedure, and are returned after severing a tube section.
20. A can body (24') comprising a closed can shell (24), produced from a metal band (1), to which a closure element (31b, 32, 31a) is fixed, wherein said metal band (1) has been formed into a tube (11), closed in circumferential direction, by at least one deformation step and a welding step, in which welding step a welding seam (11a, 124) has substantially continuously been welded in the tube's longitudinal direction, tube sections from the emerging tube (11) with the length of a desired can height having been further treated as can shells (24), characterised in that said welding seam (11a, 124) is formed as a butt-joint or jump joint in the tube's longitudinal direction, a restriction (24c, 60a) is formed at a lower front side (24b) of said can shell (24), the can bottom (31b), having a correspondingly formed fringe area, is pressed against said restriction of said can shell (24), and is firmly connected to said can shell (24) in said area of said restriction (24c, 60a) by circumferential welding.
21. Can body according to claim 20, characterised in that the can bottom (31b) is arranged from the can's interior at the restriction (24c, 60a) of the can shell (24) formed towards the front side (24b), and circumferential welding is formed as a laser welding seam.
22. Can body according to claim 20, characterised in that the can bottom (31b) is arranged from the exterior at the restriction (24c, 60a) of the can shell (24) formed towards the front side (24b), and circumferential welding is formed as a laser welding seam.
23. Can body according to any of claims 20 to 22, characterised in that at least one restricted area is formed at an upper front side (24a) of the can shell (24).
24. Can body according to claim 23, characterised in that a valve seat is formed at the free end of the restricted area.
25. Can body according to claim 23, characterised in that a closure element (31a), including the valve seat at the restricted area, is sealingly connected to the can shell (24), optionally by a folded seam connection, but preferably by a welding connection, particularly a laser welding connection.

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