CN1202844A - Systems and methods for manufacturing decorative shaped metal cans - Google Patents

Abstract

A method of making a metal can body (24) having a distinctive shape to enhance a customer's visual appearance, one embodiment includes the steps of providing a can body blank (10) having a substantially constant sidewall diameter, providing a die assembly (38) having at least one die wall (46), the die wall (46) defining a die cavity conforming to a desired final shape of the can body (24), positioning the can body blank (10) within the die cavity (46), and supplying a pressurized fluid into the die cavity such that the can body blank (10) is pressurized against the die wall (46) to cause the can body blank (10) to assume the desired final shape of the can body (24). It is preferred to apply axial pressure on the can body blank during the molding of the container to reduce internal stresses. The second embodiment includes the steps of radially deforming the can body blank in selected areas by a selected amount to yield a radially varying intermediate can body yet symmetrical about its axis, and superimposing a preselected mechanical deformation pattern having an axial component on the intermediate can body. Related apparatus and processes are also disclosed.

Description

Systems and methods for manufacturing decorative shaped metal cans

Background of the invention

1. Field of invention

The present invention relates generally to the field of consumer packaging, and more particularly to metal cans, such as steel and aluminum cans, commonly used to package soft drinks, other beverages, food and aerosol products.

2. Description of prior art and state-of-the-art

Metal cans for soft drinks, other beverages and other materials are of course widely used in North America and around the world. The assignee of the present invention, U.S. Philadelphia Crown Cork & Seal Company (CrownCork & Seal Company) is the world's largest designer and manufacturer of such tanks.

The technology for manufacturing and encapsulating metal cans is constantly evolving with process improvements, new materials and improvements in manufacturing techniques. Other drivers of technological development in this field include raw material prices, the nature of new materials to be packaged, and the marketing goals of large companies that manufacture and distribute consumer products such as soft drinks.

It is sometimes advantageous to have a metal container in a distinctive non-standard cylindrical can shape, so that it becomes part of the marketing appearance of the product or another indication of the origin or nature of the product. However, to the best of the inventor's knowledge, no one has developed a practical technique for producing such an irregularly shaped can at a volume and rate of production that would actually bring such a product to market.

US Patent 3,224,239 to Hansson in the mid 1960's discloses a system and process for using pneumatic pressure for reshaping cans. The process utilizes a piston to force compressed air into a tank that is seated in a mold. This compressed air forces the can wall to flow plastically until the can wall takes the form of the mold.

To the inventors' knowledge, techniques such as those disclosed in the Hansson patent have never been successfully used to reshape drawn and flattened wall cans. One reason for this is that the stresses that occur when the tank wall deforms can cause defects that can cause damage such as localized thinning, splitting or rupture. The risk of thinning can be reduced by increasing the thickness of the can wall, but this makes the production of shaped cans too expensive. The risk of cracking or cracking can be reduced by processes such as annealing, but this reduces the final product's toughness and resistance to mechanical damage.

Therefore, there is a need for an improved apparatus and process for the manufacture of shaped metal cans which is effective, efficient and inexpensive, especially compared to the processes hitherto developed for this purpose, and which reduces the Tendency to crack or crack to failure.

Summary of the invention

It is therefore an object of the present invention to provide an improved apparatus and process for the manufacture of shaped metal cans which is effective, efficient and inexpensive, especially compared to the processes hitherto developed for this purpose, and which ensures overcoming possible Internal stresses in cans that cause thinning, cracking or rupture.

In order to achieve the above and other objects of the present invention, according to a first aspect of the present invention, a method of manufacturing a metal can body with a characteristic shape so as to increase the visual image of customers comprises the following steps: (a) providing a can body blank; (b ) providing a mold arrangement having at least one mold wall forming a mold cavity conforming to the desired final shape of the can body, the mold arrangement being composed of more than one component, at least one of which can be moving toward the other part in a direction substantially parallel to the axis of the can body blank, the mold wall comprising an inwardly projecting portion and an outwardly projecting portion, (c) positioning the can body blank within the mold cavity so that Precompressing the can body stock by means of an inwardly projecting portion of the mold wall; (d) supplying a pressurized fluid into the mold cavity so that the can body stock is pressed against the mold wall so that the can body stock assumes the desired can shape The final shape of the tank body, the pre-compression performed in step (c) minimizes the amount of outward deformation required to obtain the final shape of the tank body; (e) substantially simultaneously with step (d), axially toward the other The part moves at least one of the mold parts.

According to a second aspect of the present invention, a method of manufacturing a metal can body having a characteristic shape so as to increase the visual image of the customer includes the following steps: (a) manufacturing the can body blank; (b) at least part of the can body blank partially annealing, whereby the annealed portion of the can body stock increases ductility; (c) providing a mold assembly having at least one mold wall forming a mold cavity conforming to the desired final shape of the can body, the mold assembly Consisting of more than one part, at least one of which is movable toward the other part in a direction substantially parallel to the axis of the can body blank during operation; (d) positioning the can body blank in the mold cavity; (e ) supplying a pressurized fluid into the mold cavity so that the can body blank is pressed against the mold wall so that the can body blank assumes the desired final shape of the can body; (f) substantially simultaneously with step (e), along At least one of the mold parts is moved axially toward the other part.

According to a third aspect of the present invention, an apparatus for manufacturing a metal can body having a characteristic shape to enhance a customer's visual image comprises: a structure for making can body blanks; a molding structure including a mold assembly, the mold assembly having at least one mold wall defining a mold cavity conforming to the desired final shape of the can body, said mold wall comprising an inwardly projecting portion and an outwardly projecting portion, the mold means being formed from more than one part, At least one part is movable toward the other part in a direction substantially parallel to the axis of the can body blank during operation; seating structure for seating the can body blank in the mold cavity so as to utilize the inwardly projecting portion of the mold wall Pre-compressed can body blank; fluid supply structure for supplying a pressurized fluid into the mold cavity so that the can body blank is pressed against the mold wall so that the can body blank has the desired final shape of the can body, the pre-compression The amount of outward deformation required to obtain the final shape of the can body is minimized; the axial reduction structure is used to move at least one mold part axially towards another part.

According to a fourth aspect of the present invention, an apparatus for manufacturing a metal can body having a characteristic shape to enhance the visual image of a customer comprises: a structure for manufacturing a can body stock; at least partially annealing at least a portion of the can body stock structure, whereby the annealed portion of the can body blank increases ductility; the molding structure comprises a mold assembly having at least one mold wall defining a mold cavity conforming to the desired final shape of the can body, the mold Apparatus consisting of more than one part, at least one of which is movable towards the other part in a direction substantially parallel to the axis of the can body blank during operation; seating structure for seating the can body blank in the mold cavity The fluid supply structure is used to supply a pressurized fluid into the mold cavity, so that the tank body blank is pressed against the mold wall, so that the tank body blank presents the desired final shape of the tank body; the axial reduction structure is used for along the At least one mold part is moved axially toward another part.

The above and other various advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and purposes of use, reference should be made to the accompanying drawings and accompanying descriptive matter which form a further part hereof, in which there is illustrated and described a preferred embodiment of the invention.

Brief description of the drawings

Figure 1 is a cross-sectional view of a can body blank or preform manufactured in accordance with a preferred embodiment of the present invention;

Fig. 2 is a side elevational view of a shaped tank body of a preferred embodiment of the present invention;

Fig. 3 is a kind of schematic diagram of the equipment for manufacturing the shaped tank body of preferred embodiment of the present invention;

Figure 4 is a partial cross-sectional view of the mold device in the first state in the apparatus shown in Figure 3;

Fig. 5 is a partial sectional view of the mold device in a second state in the apparatus shown in Fig. 3;

Fig. 6 is the schematic diagram of the pressure supply equipment that mold device is used in Fig. 3;

Figure 7 is a schematic diagram of the pre-compression step carried out in the apparatus of Figure 3;

Fig. 8 is a schematic diagram of the pressing flange step in the method according to the second embodiment of the present invention;

9 is a schematic diagram of a spinning step in a method according to a second embodiment of the present invention;

Fig. 10 is a schematic diagram of an embossing step that may be performed as a second step in the above-described second or third embodiment of the present invention.

Detailed Description of Preferred Embodiments

Referring now to the drawings in which like numerals indicate corresponding constructions throughout, and with particular reference to Figures 1 and 2, a can body stock or preform 10 according to a preferred embodiment of the present invention is a two-piece can body, It is preferably formed by the well known drawing and flattening process. Can body stock 10 includes a substantially cylindrical side wall surface 12 , a bottom 14 and neck-shaped upper portion 16 . Alternatively, the upper portion of the cylindrical side wall 12 may be straight.

As is well known in the art, the can body stock 10 must be rinsed after the drawing and flattening process and then must be dried before being sent for decoration. The drying process typically takes place at a temperature of about 250 degrees Fahrenheit (equivalent to about 121 degrees Celsius). According to one aspect of the present invention, drying is performed at a higher temperature than is conventionally done so as to partially anneal at least selected portions of the can body stock 10 . Heat source 18 is schematically depicted in Figure 1 and is preferably part of the drying apparatus, but may be at any point in the apparatus prior to molding the apparatus. As will be discussed in more detail below, the can body stock 10 is preferably formed of aluminum, preferably with a partial annealing process substantially in the range of about 375 degrees Fahrenheit (about 190.5 degrees Celsius) to about 550 degrees Fahrenheit (about 288 degrees Celsius) Complete, a more preferred range is from about 450 degrees Fahrenheit (about 232 degrees Celsius) to about 500 degrees Fahrenheit (about 260 degrees Celsius), with a most preferred temperature being about 475 degrees Fahrenheit (about 246 degrees Celsius). This is very different from the real annealing process, which involves temperatures above 650 degrees Fahrenheit (about 353 degrees Celsius). The purpose of partial annealing is to give the can body stock 10 sufficient ductility to produce a shaped can 20 as shown in Figure 2, but with a toughness greater than that of a fully annealed can body stock.

Alternatively, partial annealing can be performed in a furnace such as a painting or decorating furnace rather than in a drier.

Alternatively, the can body stock 10 may be fabricated from steel rather than aluminum. In this case, the preferred temperature range for the partial anneal is substantially 1112 degrees Fahrenheit (600 degrees Celsius) to about 1472 degrees Fahrenheit (800 degrees Celsius). More preferably, the partial annealing is performed at about 1382 degrees Fahrenheit (750 degrees Celsius).

Referring now to FIG. 2, the shaped can 20 has been subjected to decorative and distinctive shaping to increase its visual appeal to consumers. As can be seen in FIG. 2 , can body 20 includes a bottom 26 and a shaped sidewall 22 that is substantially different in shape from standard cylindrical can body shapes such as can body stock 10 . The shaped sidewall 22 includes regions such as ridges 30 and grooves 32 where it may be desirable to deviate particularly from the cylindrical shape. According to an important aspect of the present invention, the decoration is provided on the outer surface of the shaped side wall 22 in such a manner that the decoration will be accentuated at those portions of the side wall which require particular departures from the cylindrical shape. As can be seen in FIG. 2, a first decoration (which may be a lighter color) is provided on the rib 30, and a second decoration 36 (which may be a lighter color) is provided in at least one groove 32. darker colors). By providing such selective decoration, and by properly aligning such decoration with deviations in the formed side wall 22, a visual effect of optimum fit can be obtained which would not be possible through separate tank forming or tank Decorated to obtain.

Referring again to FIG. 2, the shaped side wall 22 also has a flat area 28 where writing or labeling can be applied and is closed with a can end 24 which is sealed using a conventional double seaming process.

According to the preferred method, after being partially annealed on the drying table by the heat source 18, the can body blank 10 is transported to a decorator where a distinctive decoration is applied, while the can body blank 10 is still in its cylindrical configuration, at Markings may also be added during the decoration process to align the decoration content to the mold contour during subsequent forming steps, as described in more detail below.

Referring now to FIG. 3, there is shown an apparatus 38 for making shaped cans 20 of the type shown in FIG. 2 in accordance with a preferred embodiment of the present invention. As can be seen in FIGS. 3 , 4 and 5 , the apparatus 38 includes a mold 40 having mold walls 46 forming a mold cavity 42 conforming to the desired final shape of the formed can body 20 . As shown in FIG. 7, the mold 40 is of the split-wall type, and the mold wall 46 includes an inwardly projecting portion 48 having a diameter smaller than the diameter of the cylindrical side wall 12 of the can body blank 10 shown in phantom in FIG. 7b. Db. The mold wall 46 also includes a plurality of outwardly projecting portions having a diameter greater than the diameter Db of the side wall 12 of the can body blank 10 . In other words, the inwardly protruding portion 48 tends to compress the cylindrical side wall 12 of the can body stock 10 to the position 12' shown by the solid line in Figure 7b, while the side wall 12 of the can body stock 10 must The outwardly projecting portion 50 expands to conform to the mold wall 46 . Preferably, the circumferential length of the cylindrical side wall is kept constant when pressed in this way, that is, the circumferential length of the pressed cylindrical side wall 12' is equal to the circumference of the side wall 12 of the can body blank 10. equal in length.

As shown most clearly in FIG. 3, the mold assembly 40 has three die parts 82, 46 and 84 which constitute the neck ring, mold side walls and bottom support, respectively. The die parts are separated from each other by gaps or "split lines" 86 and 88 . For the convenience of processing, the base supporting part die 84 is made into two pieces, and a central part 90 supports the base arch of the tank body. Neck ring 82 provides simple support to the neck of the can. Together these parts form the inner chamber or mold cavity 42 which houses the can and which, after blow forming, is machined into the desired final shape of the can. Air holes 49 (see Figures 4 and 5) are provided to allow entrained air to escape during forming.

A pair of sealing and support rings 92, 94 and a rubber sealing ring 96 are provided to seal the top edge of the container body. A space saving mandrel 98 passes through the center of the seal and support rings 92, 94, 96 to a location just above the base support domes. The mandrel 98 supplies air to the tank cavity within the cavity 42 through a central bore 100 and radial passages 102 . The apparatus also includes an upper piston 104 and a lower piston 106 which together apply a load to both ends of the can in the mold cavity 42 . The lower piston 106 is movable upwards by means of a supply of pressurized air which is delivered to the piston via passage 108 . Likewise, the upper piston can be moved downwards by means of a supply of pressurized air, which is delivered to the piston via passages 110 and 112 . In the preferred embodiment shown, a channel 110 connects the central bore 100 of the spindle 98 so that the upper piston and pot chamber share a common supply air. The common supply air branches off at the junction of the air passage 112 in the piston 104 and the central spindle bore 100 to supply the piston 104 and the pot, thereby minimizing losses and maintaining the same pressure feeding the pot and piston. Mechanisms are preferably provided to control the rate of air flow to each piston and tank chamber. Tank pressure and piston pressure can therefore be closely controlled.

Fig. 6 shows a schematic flow diagram showing the air supply to the piston and the tank cavity. In this figure, the upper piston 104 and the seal and support rings 92 , 94 are shown schematically as a single unit 114 . Likewise, base supports 84 , 90 and lower piston 106 are shown as a single unit 116 . Units 114 and 116 and neck ring 82 are movable, while die sidewall die 46 is shown as stationary.

The process includes two pressure supplies. Pressure supply 118 supplies pressurized air to the top piston 104 and the pot cavity within mold cavity 42 ; pressure supply 120 supplies pressurized air to the lower piston 106 only.

Each of the two supply flow paths includes a pressure regulator 122 and 124 , storage containers 126 and 128 , air supply valves 130 and 132 , and exhaust valves 134 and 136 . In addition, the downforce supply flow path 120 includes a flow regulator 138 . The upper pressure supply flow path 118 may also include a flow regulator, although it is not critical whether the flow can be adjusted in both supply flow paths. The storage vessels 126, 128 prevent large drops in supply pressure during the process.

Typically, high pressure air of about 30 bar is introduced into the tank cavity and drives the tank top. The air pressure driving the bottom piston 106 is typically about 50 bar, depending on the piston area. The air pressure within the mold cavity 42 provides the force needed to expand the can body blank outwardly, but also applies unwanted forces to the neck and base of the can, which results in longitudinal tension in the side walls of the can. So two pistons are used to drive the top and bottom of the tank, creating a force that acts to counteract this tension in the side walls of the tank.

The air pressure supplied to the piston is critical during forming to avoid damage to the can due to splitting or creasing. If the tension in the tank sidewall is not sufficiently counteracted by the piston pressure because the pressure in the piston is too low, splitting will occur. Conversely, the supplied air pressure should not be so high that ripples will form in the side walls.

For this reason, there is preferably no need for a stopper to limit the stroke of the piston. If the stroke is limited, it is impossible for the can to expand sufficiently against the mold wall until the piston reaches the stop. If this happens, the tension in the side wall of the tank cannot be balanced by the piston pressure, with the ensuing risk of splitting. In fact, the contact of the expanding pot with the side walls of the mold prevents further movement of the piston.

It should therefore be noted that it is always best to maintain a balance between tank cavity pressure and piston pressure throughout the forming cycle so that the rate of pressure rise in the cavity and behind the piston should be balanced throughout the cycle, especially when the tank wall yields hour. The rate of pressure rise can be controlled by flow regulator 138 or by adjusting the supply pressure via pressure regulators 122 , 124 .

By adjusting the pot cavity pressure relative to the pressure applied to move the mold parts 82, 46, 84 towards each other, the apparatus can be operated in one of three different ways. By applying as little pressure as possible to the outer mold parts 82, 84, it is possible to operate the apparatus such that the mold parts are only moved towards one another without exerting any force on the can body. This will reduce the gaps 86, 88 in the mold assembly 40 as the can shrinks longitudinally during expansion and will reduce but not necessarily counteract the axial tensile stresses developed in the side walls of the can during expansion. Alternatively, by applying increased pressure to drive the outer mold parts towards each other, a slight longitudinal or axial force is applied to the can body, which is substantially equal to the axial tensile stress in the side wall of the can body, Thereby balancing this stress and preventing subsequent weakening and possible splitting of the tank. A third operation is to apply even greater pressure to drive the outer mold parts towards each other to apply an axial pressure to the can body that is greater than that required to counteract the tensile stress in the sidewall during operation. Ideally, the net pressure provided will not cause wrinkles to form.

To form the tank, the vent valves 130, 132 are first opened. If a better match between piston and tank pressure is required, there can be a short delay between the opening times of the two vent valves, but a higher rate of pressure rise is required in one flow path in order to maintain this balance. Delays can also be used to compensate for different tube lengths, maintaining pressure balance during forming time. As described above with reference to FIG. 3 , the upper feed air flow 118 is split in two for the piston 104 and the tank cavity as close as possible to the piston 104 .

The device is designed in such a way that at the latest when each piston has reached its maximum stroke, the pot is completely reshaped without the gaps 86 , 88 eventually being closed. Closure of the gap can cause the tank to split due to excessive tension in the side walls, in the same way that the piston is restricted from moving before full expansion occurs. However, in the end the gap should not be too large, as any eye-visible markings on the side walls become too conspicuous, although removing the sharp edges at the split line alleviates this problem.

Air is removed through valves 134 and 136 once the forming operation is complete. Obviously the exhaust valve is closed throughout the actual forming process. It is important that the two supply streams are exhausted simultaneously because the pressure exerted by the piston to balance the tank chamber pressure (longitudinal tension) may be greater than the axial strength of the tank, so non-uniform venting leads to damage to the tank.

As best seen in Figure 4, can body blank 10 is preferably positioned within mold cavity 42, with the interior space thereof sealed in communication with a source of pressurized fluid, as described above. As can be seen in FIG. 4 , the cavity 42 is designed such that a slight pressure is exerted on the can body blank 10 when the can body blank 10 is inserted therein. This is preferably accomplished by forming the mold means parts into two halves 52, 54 shown in FIG.

When the mold halves 52, 54 are closed around the cylindrical side wall 12, the inwardly projecting portion 48 of the mold wall 46 thus compresses or pre-compresses the cylindrical side wall 12 to an amount as large as Rin shown in FIG. distance. After the mold is closed and sealed and pressurized fluid is supplied into the mold cavity 46 to force the can body blank 10 against the mold wall 46 , the can body blank 10 will be forced to assume the desired final shape of the formed can 20 . The state of the shaped side wall 22 after this step is shown in FIG. 5 . In this step, the cylindrical side wall 12 of the can body blank 10 is expanded to an amount of Rout, which is again shown schematically in FIG. 7 .

The pre-compression achieved by the closing of the mold halves 52, 54 deflects the sidewall 12 of the can body blank 10 radially inwardly by a distance Rin, preferably between about 0.1 and about 1.5 millimeters. More preferably, the distance is in the range of 0.5 to about 0.75 millimeters. The distance Rout by which the cylindrical sidewall 12 expands radially outward to form the outermost portion of the shaped sidewall 22 is preferably in the range of about 0.1 to about 5.0 millimeters. A more preferred range for the distance Rout is about 0.5 to 3.0 mm. The most preferred distance Rout is about 2 mm.

In order to appreciate the benefits gained by pre-compressing the cylindrical sidewall 12 prior to the expansion step, it must be understood that some amount of annealing or partial annealing may be useful, particularly in the case of aluminum cans, in order to achieve the necessary ductility for the expansion step Down. However, the more complete the annealing, the ultimately less strong and tough the shaped can 20 will be. The use of pre-compression to achieve a significant difference between the innermost and outermost portions of the pattern superimposed on the final formed can 20 reduces the actual amount of radial expansion necessary to obtain the desired pattern. Accordingly, the amount of annealing that needs to be applied externally to the can body stock 10 is also reduced. Thus, the pre-compression step allows the desired pattern to be superimposed on the formed can 20 with a minimum amount of annealing and resulting loss of strength, thereby allowing the cylindrical sidewall 12 of the can body blank 10 to be robust to such processes. as thin as possible.

As an embodiment of the invention, the mold walls may be made of porous material to allow air trapped between the side walls of the can blank and the mold walls to escape during operation, although air holes may still be required. One such material is porous steel, which is commercially available from AGA, Leydig, Sweden.

For quality monitoring and control purposes, the fluid pressure within the mold cavity 46 is monitored during and after the expansion process by the configuration of the pressure proximity device 69 , which is schematically shown in FIG. 5 . The pressure monitor 69 is of conventional construction. If the can leaks during the expansion process, or if an anomaly in the top flange or neck of the can creates a poor seal against the gas control needle, the pressure in the mold cavity will be lower in the mold chamber than if this were not the case. 46 falls much faster. The pressure monitor 69 will sense this and will indicate to the operator that the tank may be cracked.

In the case of steel cans, the pressure within the mold chamber can be made high enough to cause the can body to form, for example, a corrugated pattern in which a plurality of circumferential ridges are formed on the container.

A second method and apparatus for producing a metal can body having a distinctive shape that enhances the visual image of the can body to the customer is disclosed in FIGS. 7 and 9 . 8 and 9 show a third embodiment. According to the second and third embodiments, a metal can body having a characteristic shape is manufactured by the following procedure, which is to provide a can body blank 10 as shown in FIG. 1, which has a side wall with a substantially constant diameter. 12, and then deform the can body blank 10 by a selected amount in a selected area in the radial direction to obtain an intermediate tank body 74 that is trimmed radially and still symmetrical to its entrance, and then superimposed on the intermediate tank body 74 Preselected mechanically deformed patterns. Now describing a second embodiment of the present invention, a flanging apparatus 62 of the type well known in the art includes an anvil 66 and a flanging tool 64 . The press flange apparatus 62 is used to radially deform the can body stock 10 into the radially trimmed intermediate can body 74 shown in FIG. 9 . As can be seen in FIG. 9 , the intermediate tank 74 has no deformation with an axial component and is substantially cylindrical around the inlet of the tank 74 . A preselected pattern of mechanical deformations (in this case ridges and grooves) is then superimposed on the intermediate can body using embossing tool 76 so that a shaped can 20 of the type shown in FIG. 2 can be produced.

In a third embodiment shown in FIGS. 8 and 9 , a spinning device 68 is used to radially deform the cylindrical sidewall 12 of the can body blank 10 into an intermediate can body 74 . As is well known in the art, the spinning apparatus 68 includes a mandrel 70 and a forming roll 72 opposite the mandrel 70 . After this process, the embossing step shown in Figure 9 is preferably carried out on the thus formed intermediate can body 74 in the same manner as described above.

As an alternative to the embossing step shown in Figure 9, the intermediate tank 74 produced by the method shown in Figure 7 or Figure 8 could alternatively be placed in a pneumatic cylinder of the type shown in Figures 3-5 The expansion die or mold assembly 40. The intermediate tank body 74 is then expanded in the same manner as above to obtain the shaped tank 20 .

In the second and third methods described above, the can body stock 10 is also preferably partially annealed by the heat source 18 during the drying process, but preferably to a lesser extent than in the first embodiment described. Preferably, the annealing of the second and third methods described above is performed at a temperature in the range of about 375 degrees Fahrenheit (about 190 degrees Centigrade) to about 425 degrees Fahrenheit (about 218 degrees Centigrade). The method described with reference to Figures 7 and 8 therefore requires less annealing than the method described in the preceding examples, meaning that for a given weight or wall thickness a greater strength can be made for the shaped can 20, or relative to that described with the described method. The can produced by the first method can reduce the weight of the formed can 20 . But the disadvantages of the second and third methods include more machining and greater mechanical complexity, as well as more wear and tear on the tank, damage and possible destruction of the trim due to the additional mechanical handling and handling .

It is to be understood, however, that while the foregoing description has set forth many of the features and advantages of the invention, as well as the functions of the structural details of the invention, the disclosure is by way of illustration only and is defined in terms of the terms set forth in the appended claims. The details may vary, especially the shape, size and arrangement of parts, within the scope of the inventive principle well demonstrated in its broad and general sense. Or, for example, a draw-redraw process, a draw-thin-redraw process, or a three-piece welded or bonded manufacturing process.

Claims (35)

1. make characteristic shape so that improve the method for the metal can of client's visual image for one kind, comprise the following steps:

(a) make the tank body blank;

(b) make at least a portion of tank body blank carry out part annealing at least, make the annealing portion of tank body blank improve ductility thus;

(c) provide a die device, this die device has at least one mold wall that limits mold cavity, this mold cavity meets the net shape of the tank body of wanting, described die device is by constituting more than parts, and one of them described parts can move to another parts along the direction that is arranged essentially parallel to tank body blank axis during operation;

(d) described tank body blank is placed in the described mold cavity;

(e) charging fluid is supplied in the described mold cavity, make described tank body blank be stressed and, make described tank body blank present desired tank body net shape near described mold wall; And

(f) basically with step (e) side by side, one of them described mold component is moved to another parts vertically.

2. a method of claim 1, wherein described part annealing steps is to carry out to the temperature range of about 550 degrees Fahrenheits (288 ℃) in about 375 degrees Fahrenheits (190.5 ℃).

3. method as claimed in claim 2, wherein, described part annealing steps is to carry out to the temperature range of about 500 degrees Fahrenheits (260 ℃) in about 450 degrees Fahrenheits (232 ℃).

4. method as claimed in claim 3, wherein, described part annealing steps is to carry out in the temperature of about 475 degrees Fahrenheits (246 ℃).

5. the method for claim 1, wherein, die device comprises three parts, and wherein step (f) comprises at least two parts in three parts is shifted to the second place towards the 3rd parts from primary importance, these parts are spaced-apart by the gap of leading in the mold cavity in primary importance, and the gap size between the mold component dwindles and still leads in the mold cavity in the second place.

6. method as claimed in claim 5, wherein step (f) also comprises the longest expansion point place that the gap is arranged on the tank body blank.

7. the method for claim 1, the wherein axial force balance that applies in power that in step (e), applies and the step (f) by charging fluid.

8. described method as claimed in claim 1, wherein step (f) comprises to the tank body blank and applies an axial force, this axial force is enough to that the sidewall to the tank body blank applies a net compressive force during step (e).

9. the method for claim 1, wherein said tank body blank has the sidewall of a diameter substantial constant.

10. the method for claim 1, wherein step (b) is in a japanning or decorate in the stove and carry out.

11. the method for claim 1, wherein step (b) is carried out during the described tank body blank of drying.

12. make characteristic shape so that improve the equipment of the metal can of client's visual image, comprising for one kind:

Make the mechanism that the tank body blank is used;

At least make at least a portion of tank body blank carry out the mechanism of part annealing usefulness, make the annealing portion of tank body blank improve ductility thus;

Mold mechanism, comprise a die device, this die device has at least one mold wall that limits mold cavity, this mold cavity meets the net shape of the tank body of wanting, described die device is by constituting more than parts, and one of them described parts can move to another parts along the direction that is arranged essentially parallel to tank body blank axis during operation;

Placement Cell is used for described tank body blank is placed in the described mold cavity;

Fluid supply mechanism is used for a kind of charging fluid is supplied to described mold cavity, makes described tank body blank be stressed and near described mold cavity, makes described tank body blank present the net shape of the tank body of wanting; And

Axially reduce mechanism, be used to make described one of them mold component to move to another parts vertically.

13. an equipment as claimed in claim 12, wherein, described part annealing steps is to be carried out to the temperature range of about 550 degrees Fahrenheits (288 ℃) in about 375 degrees Fahrenheits (190.5 ℃) by described drier.

14. an equipment as claimed in claim 13, wherein, described part annealing steps is to be carried out to the temperature range of about 500 degrees Fahrenheits (260 ℃) in about 450 degrees Fahrenheits (232 ℃) by described drier.

15. an equipment as claimed in claim 14, wherein, described part annealing steps is to be carried out in the temperature of about 475 degrees Fahrenheits (246 ℃) by described drier.

16. equipment as claimed in claim 12, wherein, the described mechanism of axially reducing comprises having three described molded mechanisms and the mechanism that is used at least two parts of described three parts are shifted to from primary importance towards the 3rd parts the second place that limit the parts of described mold cavity, these parts are separated each other by the gap of leading in the mold cavity in this primary importance, and the gap size between these mold components reduces and still leads in the mold cavity in this second place.

17. an equipment as claimed in claim 16, wherein, the gap in the mould is arranged on the maximum swelling point of container.

18. an equipment as claimed in claim 12, wherein, the described mechanism of axially reducing comprises to the tank body blank and applies an axial force, and this power is enough to that the sidewall to the tank body blank applies a net compressive force between the phase of expansion.

19. an equipment as claimed in claim 12, wherein, the described mechanism of axially reducing is manufactured and be arranged to one of balance and be applied to power on the container body blank by described fluid supply mechanism.

20. an equipment as claimed in claim 12 also comprises an independent charging fluid circuit, is used to supply with described fluid supply mechanism and described axial compression mechanism.

21. an equipment as claimed in claim 12, wherein, the mechanism of described part annealing usefulness comprises a japanning or decorates stove.

22. an equipment as claimed in claim 12, wherein, the mechanism of described part annealing usefulness comprises a tank body drier.

23. container of making according to the method that proposes in the claim 1.

24. make characteristic shape so that improve the method for the metal can of client's visual image, comprise the following steps: for one kind

(a) make the tank body blank;

(b) make at least a portion of tank body blank carry out part annealing at least, make the annealing portion of tank body blank improve ductility thus;

(c) provide a die device, this die device has at least one mold wall that limits mold cavity, and this mold cavity meets the net shape of the tank body of wanting;

(d) described tank body blank is placed in the described mold cavity; And

(e) charging fluid is supplied in the described mold cavity, make described tank body blank be stressed and, make described tank body blank present the net shape of the tank body of wanting near described mold wall.

25. a method as claimed in claim 24, wherein, described part annealing steps is to carry out to the temperature range of about 550 degrees Fahrenheits (288 ℃) in about 375 degrees Fahrenheits (190.5 ℃).

26. a method as claimed in claim 25, wherein, described part annealing steps is to carry out to the temperature range of about 500 degrees Fahrenheits (260 ℃) in about 450 degrees Fahrenheits (232 ℃).

27. a method as claimed in claim 26, wherein, described part annealing steps is to carry out in the temperature of about 475 degrees Fahrenheits (246 ℃).

28. a method as claimed in claim 24, wherein, step (b) is carried out in japanning or decoration stove.

29. a method as claimed in claim 24, wherein, step (b) is at the described tank body of drying, carries out during the blank.

30. make characteristic shape so that improve the equipment of the metal can of client's visual image, comprising for one kind:

Make the mechanism that the tank body blank is used;

At least make at least a portion of tank body blank carry out the mechanism of part annealing usefulness, make the annealing portion of tank body blank improve ductility thus;

Mold mechanism comprises a die device, and this die device has at least one mold wall that limits mold cavity, and this mold cavity meets the net shape of the tank body of wanting;

Placement Cell is used for described tank body blank is placed in the described mold cavity; And

Fluid supply mechanism is used for charging fluid is supplied to described mold cavity, makes described tank body blank be stressed and near described mold wall, makes described tank body blank present the net shape of the tank body of wanting.

31. an equipment as claimed in claim 30, wherein, described part annealing steps is to be carried out in the temperature range of about 550 degrees Fahrenheits (288 ℃) in about 375 degrees Fahrenheits (190.5 ℃) by described drier.

32. an equipment as claimed in claim 31, wherein, described part annealing steps is to be carried out to the temperature range of about 500 degrees Fahrenheits (260 ℃) in about 450 degrees Fahrenheits (232 ℃) by described drier.

33. an equipment as claimed in claim 32, wherein, described part annealing steps is to be carried out in the temperature of about 475 degrees Fahrenheits (246 ℃) by described drier.

34. an equipment as claimed in claim 30, the mechanism of wherein said part annealing usefulness comprises japanning or decorates stove.

35. an equipment as claimed in claim 30, the mechanism of wherein said part annealing usefulness comprises the tank body drier.

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