JPH09285827A - Manufacture of drawing and ironing can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more stabilized ironing and to contrive cost reduction by having bearing part between a face with which the inlet half angle is formed and a face with which the outlet half angle is formed as a die in ironing. SOLUTION: The bearing part 3 substantially parallel to the axial direction is formed between an approach part 4 and a release part 5 and the inlet half angle θ1 of the approach part 4 and the outlet half angle θ2 of the release part 5 are respectively taken as within a range of 3-20 deg. and within a range of 1-20 deg.. The boundary position P2 between the approach part 4 and the bearing part 3, that is, the intersection P2 between the face with which the inlet half angle θ1 is formed and a bearing face, and the boundary position P3 between the bearing part 3 and the release part 5, that is, the intersection P3 between the bearing face and the face with which the outlet half angle θ2 is formed are respectively made into curved surfaces without a sharp edge, that is, so as to become smooth curved surfaces the radii R2 , R3 of curvatures of which are respectively >=0.1mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a drawn and ironed can by drawing and ironing (DI processing), and particularly to drawing and ironing using a metal base plate previously coated (laminated) with a resin film before DI processing. The present invention relates to a method of manufacturing a can.

[0002]

2. Description of the Related Art Generally, for use in beer cans and carbonated beverage cans, drawn and ironed cans (hereinafter referred to as DI cans) formed by drawing and ironing (DI processing) using tin-plated steel plates (tinplate) or aluminum alloy plates. Is widely used. Such a DI can is obtained by drawing (cup forming) a metal base plate into a cup having a relatively large diameter, then redrawing the cup into a cup having a small diameter, and then twice or three times on the side wall of the cup. Manufactured by adding ironing.
The resulting DI can is usually subjected to trimming, cleaning, inner surface coating, and outer surface coating of the opening end of the can, and then, if necessary, a necking process of one or more steps to reduce the opening to a small diameter. Then, flange processing is performed to make a can body.

FIG. 3 shows a die for ironing, which has been conventionally used for producing a DI can using a tin-plated steel plate or an aluminum alloy plate, and FIG. 4 shows a detailed shape of a main part thereof. 3 and 4, the die hole 2 of the die 1
The right side is the inlet side of the material and the left side is the outlet side. The portion of the minimum inner diameter between the inlet and the outlet of the die hole 2 is a bearing portion (parallel portion) 3 parallel to the central axis, and the main portion of the die hole 2 faces the bearing portion 3 from the inlet side. The approach portion 4 is tapered to reduce the inner diameter, and the release portion 5 is tapered from the bearing portion 3 toward the outlet side to increase the inner diameter. The taper angle θ ₁ of the approach portion 4 is called the inlet half angle, the taper angle θ ₂ of the release portion 5 is called the outlet half angle, and the axial length L of the bearing 3 is called the bearing length. In the production of a usual drawn and ironed can, the ironing process is performed twice or more. In the ironing process twice or more, it is usual to use dies having the same shape but different inner diameters.

By the way, in the manufacture of a conventional general DI can using a tin-plated steel plate or an aluminum alloy plate, the boundary portion 6 between the approach portion 4 and the bearing portion 3 in the ironing die, that is, the inlet half-angle θ ₁ is set. The intersection 6 between the formed surface and the bearing surface and the boundary portion 7 between the bearing portion 3 and the release portion 5, that is, the intersection 7 between the bearing surface and the surface forming the exit half-angle θ ₂ are both the surface quality and shape of the DI can. In consideration of accuracy and the like, it is general to form a sharp shape, that is, a sharp edge shape which is not substantially smoothly continuous. It is extremely important in the ironing process to make the intersections 6 and 7 into a sharp shape in this way, and if the shape becomes a sag due to abrasion, surface defects called black stripes may occur or build-up may occur. It is known to cause vertical scratches and can run out of cans. The bearing surface of the bearing portion 3 is usually a straight line parallel to the axis as described above, but it may be slightly tapered in some cases.

It is necessary to determine the shape of the die for ironing as described above, in the case of directly performing DI processing on the metal base plate.
That is, it is an important technique that is indispensable when the surface of the metal base plate and the inner surface of the die are in a boundary lubrication state via the lubricating oil. As the lubricating oil in the squeezing and ironing process, an oil having a viscosity of about 20 to 150 cst containing a synthetic oil such as a mineral oil or an ester as a main component is applied to the metal base plate in advance, and the first stage cup forming (squeezing) Similarly, a water-soluble coolant mainly composed of mineral oil or synthetic oil is used in (processing), and the same coolant is usually used in subsequent redrawing and ironing processes.

By the way, in the production of the conventional DI can as described above, sufficient degreasing cleaning is necessary to wash off the lubricating oil after DI processing, and coating processing on the inner and outer surfaces is required after DI processing and cleaning. However, the heat and exhaust gas discharged in the cleaning process and the painting process are not preferable in terms of environmental hygiene, and therefore improvement is desired.

In the case of DI cans made of aluminum alloy,
Available aluminum alloys are limited to Al-Mn-Mg-based alloys (No. 3000 series alloys) represented by 3004 alloys or 3104 alloys, and the degree of freedom in alloy selection is limited in the actual situation. is there. That is, these Al-Mn-Mg-based alloys are excellent in ironing workability, but other aluminum alloys are generally inferior in ironing workability, so that galling is likely to occur in ironing work, and continuous It has been difficult to stably manufacture high-quality DI cans. Therefore, even aluminum alloys that have excellent formability and strength other than ironing workability are unsuitable for DI cans, which is a bottleneck for further strengthening and thinning of aluminum alloy DI cans. It was.

To explain this point in more detail, 3000
When a DI can such as a beer can is manufactured by using a No. system Al-Mn-Mg alloy, ironing is generally performed at a plate thickness reduction rate of about 60%, and an aluminum alloy of another system is used. When manufacturing DI cans such as beer cans, a plate thickness reduction rate of about 60% is desired by ironing, but for example, the strength is much higher than that of 3000 series alloys and the formability other than ironing is excellent. A such as 5182 alloy
When the DI processing is performed on the 1-Mg-based alloy (5000-based alloy), rupture (can break) occurs in the ironing processing with a plate thickness reduction rate of about 30% or more, and therefore, in practice, 50
It was difficult to use the 00 alloy in DI cans.
Therefore, using another aluminum alloy having higher strength than the 3000 series alloy used in the conventional DI can, for example, 5000 series alloy, to further strengthen the DI can and reduce its thickness, It used to be difficult in the past.

On the other hand, DR cans and D without ironing
In the production of deep-drawn cans such as RD cans, instead of coating after molding, a flat metal plate before molding is previously coated (laminated) with an organic resin film, and the laminated plate is deep-coated. It has been partially put into practical use to perform can-making processing such as drawing processing. And D
Also for the production of I cans, the same procedure as above was carried out using D
It is considered to omit the coating process after DI processing by carrying out I processing, for example, Japanese Patent Laid-Open No. 56-104.
No. 51 or JP-A-60-170532 proposes a method for producing a DI can using a laminated plate.

When performing DI processing using a laminated plate as described above, it is necessary to coat the metal base plate with resin before DI processing, but in the case of a DI can body having a DI processed deep can shape. Compared to the case where coating is applied, resin coating on a flat metal base plate can be performed much more easily and easily, and exhaust heat and exhaust gas after DI processing It is possible to reduce the number significantly as compared with the case where the coating process is performed. Also, regarding the cleaning and removal of the lubricant after DI processing, there is a possibility that an easily removable lubricant different from the case of direct ironing processing on the metal base plate may be used in the ironing processing on the laminated plate, and therefore the cleaning process It is considered that the simplification can be achieved. Therefore, it is considered that productivity can be improved as a whole and the problems in environmental hygiene are reduced.

Further, when DI processing is performed on the laminated plate, since the surface of the metal base plate is covered with the resin film during the ironing process, there is no direct friction between the metal base plate and the mold, and therefore, The metal base plate itself is not required to have high ironing workability as in the case of directly ironing it, and as a result, aluminum alloy D
Even when producing I cans, the aluminum alloy used is an Al-Mn-Mg-based alloy (300
It is possible to use other aluminum alloys having higher strength and the like for the DI can as a result of being no longer limited to the No. 0 type alloy), and thereby making it possible to make the DI can thinner and have higher strength. Conceivable.

For example, the No. 5000 series alloy has remarkably higher strength than the No. 3000 series alloy and has excellent formability other than the ironing workability as described above.
Even if the No. 00 alloy is used as a metal base plate for DI cans, if it is used as a laminated plate as described above, the metal base plate itself does not need to have excellent ironing workability. Ironing can be performed to a certain extent, and it becomes possible to stably manufacture DI cans. Also, by applying an aluminum alloy having a higher strength than conventional 3000 series alloys to DI cans, It is considered that further higher strength and thinner wall can be achieved.

[0013]

When the DI plate is actually subjected to DI processing as described above, there are the following problems in reality, including the methods proposed above, and therefore the actual mass production scale. The fact is that it was hardly applied to the can manufacturing at.

That is, although there is no big problem in the light ironing process in which the plate thickness reduction rate is less than about 30%, when performing the ironing process in which the plate thickness reduction rate is 30% or more, the coating film or the resin film on the side wall of the cup is formed. The adhesiveness of the resin film is remarkably reduced, and the resin film is often scratched or cracked or peeled off, which deteriorates the appearance of the product and reduces the commercial value. Further, during the drawing process-redrawing process-ironing process of 30% or more, the crystallization of the resin progresses and the workability deteriorates, and finally the resin film becomes cloudy (generation of fine cracks) or breaks. May occur, resulting in defective products. Of course, even if ironing with a plate thickness reduction rate of 30% or more, it may seem that there is no problem in visual appearance after processing, but even in that case, the metal exposure amount measured as the enamel value (ERV) is abnormal. It is usually high. And when forming deep can bodies such as beer cans and beverage cans, it is usual to require severe ironing with a plate thickness reduction rate of 30% or more, and generally 60% of ironing. As described above, the occurrence of product defects in ironing with a plate thickness reduction rate of 30% or more is a major obstacle in actually applying the laminated plate to DI processing.

As described above, the reason why product defects occur in the ironing process with the plate thickness reduction rate of 30% or more is that not only the performance of the resin itself is insufficient, but also the progress of the process as described above. It is conceivable that crystallization will proceed. As another cause, there is a problem with the die shape of ironing, and the shape of the die used for direct ironing on the conventional metal base plate is not suitable for ironing a laminated plate coated with resin. It is possible that

The present invention has been made in view of the above circumstances. When the above-mentioned laminated board is subjected to DI processing, the resin film is damaged or cracked even if it is ironed with a plate thickness reduction rate of 30% or more. No peeling or clouding occurs, which makes it practically possible to manufacture DI cans using a laminated plate.
DI aluminum alloy plates other than 1-Mn-Mg-based alloy
Provided is a method of manufacturing a DI can that can be applied to a can.
Moreover, it aims at providing the die for ironing suitable for manufacture of the DI can.

[0017]

[Means for Solving the Problems] In order to solve the above-mentioned problems, as a result of the inventors' earnest experiments and studies, as a result, the shape of the drawing die was changed to a conventional ordinary DI processing of a metal base plate. The inventors have found that the above-mentioned problems can be solved by using a specific shape different from that used, and by appropriately performing heat treatment in the middle of DI processing, and have completed the present invention.

Specifically, in the invention of claim 1, a metal base plate having a resin film laminated on the surface is subjected to drawing, redrawing and ironing,
In the method for producing a drawn and ironed can, the die entrance half-angle is 3 ° to 20 ° as the die in the ironing process.
, The die exit half-angle is in the range of 1 ° to 20 °, and the intersection of the surface forming the entrance half-angle and the surface forming the exit half-angle is a curved surface having a curvature radius of 0.1 mm or more. Further, it is characterized by performing ironing processing with a plate thickness reduction rate of 30% or more.

The invention of claim 2 is a method for producing a drawn and ironed can by subjecting a metal base plate having a resin film laminated on its surface to drawing, redrawing and ironing. As the die for ironing, the die inlet half angle is in the range of 3 ° to 20 °, the die outlet half angle is in the range of 1 ° to 20 °, and between the surface forming the inlet half angle and the surface forming the outlet half angle. Has a bearing part substantially parallel to the center axis of the die, and the intersection point of the surface forming the inlet half angle and the bearing part and the intersection point of the surface forming the outlet half angle and the bearing part each have a radius of curvature of 0.1 mm or more. It is characterized in that a die formed of a curved surface is used to perform ironing processing with a plate thickness reduction rate of 30% or more.

Further, the invention of claim 3 is the method for producing a drawn and ironed can according to any one of claims 1 and 2, wherein the drawing is performed in the first step by using a volatile lubricating oil. It is characterized by performing.

On the other hand, the inventions of claims 4 to 7 define the heat treatment in the manufacturing process of the squeezed ironing can as described above.

That is, the method for producing a drawn and ironed can of the invention of claim 4 is the method for producing a drawn and ironed can according to any one of claims 1 and 2, wherein a thermoplastic resin is used as the resin film, and At any stage after the drawing process and before the end of the ironing process, a heat treatment is performed for 5 seconds or more at a temperature within a range not lower than the glass transition temperature of the thermoplastic resin and not lower than 50 ° C. higher than the melting point. To do.

According to a fifth aspect of the present invention, there is provided a method for producing a drawn and ironed can in which, in the method for producing a drawn and ironed can according to the fourth aspect, the heat treatment is performed after the drawing process is completed and before the redrawing process is completed. is there.

Further, the method for producing a drawn and ironed can of the invention of claim 6 is the method for producing a drawn and ironed can according to claim 4, wherein the heat treatment is performed after completion of redrawing and before ironing. is there.

According to a seventh aspect of the present invention, there is provided a method for producing a squeezed and ironed can according to the fourth aspect, wherein the heat treatment is performed at a temperature equal to or higher than the melting point of the thermoplastic resin. After cooling to a temperature below the melting point, the subsequent processing is performed.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for manufacturing a DI can of the present invention, a metal base plate (hereinafter referred to as a laminated plate) coated with a resin film in advance is used as a material before DI processing. Of the drawing, redrawing, and ironing processes for the production of DI cans, the target is the case where ironing with a plate thickness reduction rate of 30% or more is added in the ironing process.

Here, the plate thickness reduction rate is (t ₀ -t when the plate thickness of the material (laminated plate) before DI processing is t ₀ and the plate thickness of the can body side wall after DI processing is t _{1. 1} ) / t ₀ ×
It is defined as 100%. Since the thickness of the side wall of the can body is not substantially reduced by the drawing and redrawing processes, the workability of the ironing process is represented by the above plate thickness reduction rate. However, in general DI
In the production of cans, it is usual to perform ironing processing twice or more, and the plate thickness reduction rate described above corresponds to the total ironing processing rate through a plurality of ironing operations.

It goes without saying that the smaller the plate thickness reduction rate of ironing is, the less the scratches and peeling of the resin film are. However, if the plate thickness reduction rate is less than 30%, thinning, which is the greatest merit of DI processing, Weight saving is not achieved sufficiently. Further, in the present invention, it is an object of the present invention to prevent the scratches and peeling from occurring even in the ironing process with a plate thickness reduction rate of 30% or more, which is likely to cause scratches and peeling in the resin film by the conventional method. Al, which is conventionally used for DI cans, when an aluminum alloy is used as a metal plate
It is an object of the present invention to enable DI machining with a plate thickness reduction rate of 30% or more even for an aluminum alloy having a poor ironing workability of a system other than a -Mn-Mg system (No. 3000 series) alloy.
Therefore, from these viewpoints, in the present invention, the plate thickness reduction rate is specified to be 30% or more. The upper limit of the sheet thickness reduction rate is not particularly specified, but it is usually about 80% or less.

Next, the laminate plate used in the present invention will be described.

The resin film of the laminated plate is not particularly limited, but it is desirable that the elongation is 50% or more as a basic performance. If the elongation of the resin film is less than 50%, DI processing, especially strict ironing processing cannot be followed,
Film breakage or peeling may occur. However, most of the resins generally used as a laminate material for the metal base plate satisfy the above elongation value.

A thermoplastic resin film is suitable as a resin film for such a laminate. Specifically, for example, olefin resin films such as polyethylene, polypropylene, and copolymers thereof, polyester films such as polyethylene terephthalate, ethylene phthalate / isophthalate copolymers, nylon 6, nylon 6.6, nylon 12, etc. Polyamide film,
A polyvinyl chloride film, a polyvinylidene chloride film or the like can be used. These resin films may be unstretched or biaxially stretched.

The thickness of the resin film is 3 μm or more, preferably 5 μm or more. If the thickness is less than 3 μm, there is a high possibility that the metal will be exposed due to the occurrence of peeling or scratches in the severe DI processing exceeding 30%. The upper limit of the thickness is not particularly specified, but it may be determined according to need such as corrosion resistance and barrier properties, and is generally about 150 μm.

The specific method for laminating the resin film on the metal base plate is not particularly limited, but a heat fusion method, dry lamination, extrusion coating method or the like can be applied. If the adhesiveness between the resin film and the metal base plate is poor, an adhesive such as a urethane adhesive, an epoxy adhesive, an olefin resin adhesive, a polyamide adhesive, or a polyester adhesive is used. You can do it. Further, in order to improve various properties such as processability, corrosion resistance, and barrier properties of the resin film, for example, a two-layer or multi-layer film of resin films of the same system having different melting points or resin films of different systems can be used.

The metal base plate on which the resin film as described above is laminated is not particularly limited, and aluminum or aluminum alloy or cold rolled steel plate can be used. Particularly in the case of the present invention, D
Since it is subjected to I processing, the surface of the metal base plate does not come into direct contact with the mold, and therefore the lubricity of the metal base plate itself need not be considered. Therefore, when an aluminum alloy is used, it is unsuitable for a DI can because it is an alloy other than an Al-Mn-Mg-based No. 3000 series alloy, which is typified by a conventionally used 3004 alloy and 3104 alloy, that is, ironing workability is poor. The aluminum alloy that has been used can also be used. For example, Al-Cu system, Al-Mg system, Al-Mg-
An aluminum alloy such as Si-based or Al-Zn-Mg-based can be used, and not only an aluminum alloy rolled plate using a DC casting ingot, but a rolled plate obtained by applying continuous casting rolling is used. You can also By making it possible to use aluminum alloys other than the 3000 series in this way, the range of choices of aluminum alloys used for DI cans is significantly expanded, and the strength and strength of the DI cans can be reduced to reduce the thickness and weight of the DI cans. The cost can be reduced. Particularly, the Al-Mg system represented by the 5182 alloy (that is, 5
Since the No. 000 series alloy has high strength and is excellent in forming workability other than ironing workability, it is optimal for increasing strength and thinning of DI cans.

The metal base plate is preferably subjected to a surface treatment before the resin films are laminated in order to improve the adhesion, corrosion resistance and workability of the films. For example, as the surface treatment of aluminum or aluminum alloy, chromic acid treatment or phosphoric acid / chromic acid treatment is preferably applied. In this case, 1 in terms of metallic chromium
It is desirable that a treatment of 0 to 300 mg / m ² is performed. On the other hand, as the surface treatment of the steel sheet, zinc plating, tin plating, nickel plating, chromic acid treatment, electrolytic chromic acid treatment and the like are applied. For example in the case of an electrolytic chromic acid treated steel sheet, it is suitable that with the chromium oxide of 1 to 50 mg / m ² at 10 to 200 mg / m ² of metallic chromium layer and a metal chromium conversion. In the case of a hard tin plate having a tin plating amount of 0.5 to 11.5 mg / m ² , it is 1 in terms of metallic chromium.
It is desirable to carry out chromic acid treatment or phosphoric acid / chromium treatment so that the amount becomes ˜30 mg / m ² .

The plate thickness of the metal base plate is not particularly limited and may be appropriately determined depending on the type of metal, the use or size of the container, but generally the plate thickness is about 0.15 mm to 0.5 mm.

Next, the shape of the drawing die which is important in the present invention will be described.

FIG. 1 is an enlarged view showing an essential part of a drawing die used in the method of claim 1, and FIG.
The main part of the drawing die used in the method is enlarged.

In the case of the die shown in FIG. 1, the taper angle of the approach portion 4, that is, the inlet half angle θ ₁ is within the range of 3 to 20 °, and the taper angle of the release portion 5, that is, the outlet half angle θ.
₂ is within the range of 1 to 20 °. A bearing portion is not formed between the approach portion 4 and the release portion 5, and the boundary position P ₁ between the approach portion 4 and the release portion 5, that is, the plane forming the inlet half angle θ ₁ and the outlet half angle θ.
The intersection point P ₁ with the surface forming ₂ is a curved surface having no sharp edge, that is, a smooth curved surface having a radius of curvature R ₁ of 0.1 mm or more.

On the other hand, in the case of the die shown in FIG.
A bearing portion 3 that is substantially parallel to the axial direction is formed between the release portion 5 and the release portion 5. The inlet half angle θ ₁ of the approach portion 4 and the outlet half angle θ ₂ of the release portion 5 are respectively the die of FIG. As in the case of, within the range of 3 to 20 °, 1 to 2
It is set within the range of 0 °. The boundary position P ₂ between the approach portion 4 and the bearing portion 3, that is, the intersection point P ₂ between the surface forming the inlet half-angle θ ₁ and the bearing surface, and the boundary position P ₃ between the bearing portion 3 and the release portion 5, that is, the bearing surface. The intersection P ₃ between the surface and the surface forming the exit half-angle θ ₂ is a curved surface having no sharp edge, that is, a smooth curved surface having curvature radii R ₂ and R ₃ of 0.1 mm or more. .

Here, the approach portion 4 is a portion that gives plastic deformation to the material (laminate plate) to be ironed, and the entrance half angle of the approach portion 4 is a mold (die and punch) and a material, In particular, it is greatly affected by the friction state between the punch and the material, but if it is less than 3 ° or more than 20 °, the axial load becomes high and breakage (can break) easily occurs. Therefore, the angle of the inlet half angle is set within the range of 3 to 20 °. The friction conditions are:
If the coefficient of friction between the die and the material is μ ₁ and the coefficient of friction between the punch and the material is μ ₂ , then μ ₁ <μ _{2 and} it is desirable to make μ ₁ as small as possible. Furthermore, the most desirable range of the inlet half angle is 5 ° to 15 °.

On the other hand, the release portion 5 on the die exit side is a portion for releasing the material in order to prevent the ironed material and the die from contacting each other more than necessary. If the exit half angle θ ₂ of the release part 5 is less than 1 °, the contact length becomes long and the DI
The side wall of the can is likely to be scratched, and if it exceeds 20 °, the contact length will be shortened, but the ironing process will become unstable,
Shape defects such as uneven thickness are likely to occur. Therefore, the exit half angle θ ₂ is set within the range of 1 ° to 20 °.

Further, the entrance half angle θ ₁ in the die of FIG.
Intersection P ₁ between the surface and the surface forming the exit half angle theta ₂ which forms a between the intersection P _2, bearing surface and the surface forming the exit half angle theta ₂ between the surface and the bearing surface forming the inlet half angle theta ₁ of the die of FIG. 2 The intersection point P ₃ is not required to have a sharp shape as described above, but it is necessary to form a smooth curved surface having curvature radii R ₁ , R ₂ , and R ₃ of 0.1 mm or more. When ironing is performed directly on a non-laminated metal base plate in the conventional general case through a lubricating oil, it is necessary to make such an intersection a sharp edge shape such as a surface defect or a can end. It has been an important requirement for preventing the occurrence of, but when performing ironing for a laminate plate pre-laminated with a resin film as in the present invention, when these intersections are sharp shapes, the peeling of the resin film or Causing scratches,
This leads to product defects. To prevent peeling and scratching of such resin films is indispensable that these intersections radius of curvature R ₁ to R ₃ and more smooth curved 0.1 mm, the radius of curvature R ₁ ~ R ₃ is 0.1m
If it is less than m, the effect cannot be sufficiently obtained. Although the upper limits of the radii of curvature R _{1 to} R ₃ at these intersections are not particularly specified,
It should be within a common sense range considering the dimensions of the entire mold. For example, when the inlet half angle is 10 °, the outlet half angle is 5 °, and the bearing length L is 0.5 mm, the intersection points P ₂ and P ₃ are 10 mm.
It is geometrically impossible to provide R of.

When the bearing portion 3 is provided as shown in FIG. 2, the bearing length L is preferably in the range of 0.25 to 1 mm. The reason why the bearing portion 3 is provided in this way is to stabilize the ironing process more. However, if the bearing length L is less than 0.25 mm, its effect is small, and if it exceeds 1 mm, the contact between the DI can and the mold is reduced. The longer the length, the more easily the side wall of the DI can is damaged.

Further, a lubrication method in DI processing when a DI can is manufactured by the method of the present invention will be described.

In the cup molding (drawing process) of the first step, a volatile lubricating oil is used as defined in claim 3. It is necessary to use a lubricating oil to protect the film in the drawing process for the laminated plate. In this case, the same mineral oil or synthetic oil as the conventional one or a water-soluble lubricating oil in which these are dispersed may be used. However, in that case, the cost reduction effect of the cleaning step, which is one of the objects of the present invention, cannot be obtained. Therefore, in the invention of claim 3, a volatile lubricating oil is used in the drawing process for the first-stage cup forming. As the volatile lubricating oil, for example, a lubricating oil containing α-olefin as a main component and having a viscosity of 2 cst or less is available. By using such a lubricating oil, not only a lubricating effect can be obtained in the first-stage cup molding but also a slight lubricating effect can be expected in the subsequent redrawing and ironing processes. Since it is used, there is almost no residual oil after the completion of DI processing, and therefore, cleaning is unnecessary, and even if simple cleaning is performed, it is possible to achieve a sufficient cost reduction of the cleaning process.

In the second-stage redrawing process and the subsequent ironing process, it is desirable to use a solution type water-soluble lubricant for the purpose of cooling and lubrication. Suitable solution-type water-soluble lubricants are, for example, those obtained by adding a little fatty acid soap, a surfactant, a rust preventive agent, etc. to water. Also in this case, as in the case of the first-stage cup molding, use of mineral oil, synthetic oil, or water-based lubricating oil in which these are dispersed in water cannot avoid a sufficient reduction effect of the washing step, and should be avoided. desirable.

Further, according to the present invention, since the laminated plate having the resin film laminated thereon is subjected to DI processing,
It is important to heat-treat the intermediate product in the middle of DI processing. That is, in general, if a resin film is processed, crystallization will proceed and the processability will decrease. If an attempt is made to further process the crystallized resin film, the resin film will eventually become clouded (generation of minute cracks) or broken, resulting in a defective product. In particular, the plate thickness reduction rate 3 which is the subject of this invention
In DI processing accompanied by ironing of 0% or more, the total processing degree is extremely high, and thus the resin film is liable to be clouded or broken. In order to prevent the occurrence of such a problem, it is desirable to perform heat treatment in the middle of DI processing to recover the workability of the resin film whose workability has deteriorated by the processing up to that point. By thus performing the heat treatment midway and once recovering the processability of the resin film, it is possible to prevent the resin film from becoming clouded or broken during subsequent processing. In particular, when a metal base plate laminated with a biaxially stretched or unstretched resin film is subjected to drawing and further redrawing, crystallization of the resin film proceeds and workability deteriorates, but the plate thickness reduction rate is 30%. % Heat treatment before performing a severe ironing process to recover the processability of the film deteriorated by the previous process, and to reduce the cloudiness of the resin film by the ironing process with a plate thickness reduction rate of 30% or more. It is possible to prevent breakage and breakage.

The conditions of the heat treatment in the middle of the DI processing may be determined according to the degree of the processing received up to that point and the processing conditions after the heat processing, but generally, the glass transition of the resin used. It is suitable to heat at a temperature in the range of the temperature or higher and the melting point + 50 ° C. or lower for 5 seconds or longer.
If the temperature is lower than the glass transition temperature of the resin, the processability is insufficiently recovered, and if heated to a temperature higher than the melting point + 50 ° C,
Problems such as the resin film flowing out and the handling being difficult due to the stickiness of the resin film occur. If the heating time is less than 5 seconds, the workability will not be sufficiently recovered. The upper limit of the heating time is suitably 3 minutes or less.
Heating for more than 3 minutes is uneconomical, and when the heating temperature is high, there is a possibility that problems such as the resin film flowing out and the handling becoming difficult due to stickiness of the film may occur. Regarding these specific heating conditions, it is sufficient to select the minimum necessary temperature and heating time according to the degree of processing, and heating conditions that are more than necessary are uneconomical.

Further, in the above heat treatment, when the heating temperature exceeds the melting point of the resin, it is difficult to process in a state where the heating temperature remains above the melting point after the heating, because it is difficult for the film to flow out or stickiness. Subsequent to processing, it is necessary to cool below the melting point. Also here
If it is cooled to a temperature below the melting point, it can be processed, but if it is processed to a temperature above the glass transition temperature of the resin, the resin film is easily scratched, so it is generally desirable to cool to below the glass transition temperature.

The timing of the above heat treatment is arbitrary as long as it is in the middle of DI processing as described above.
Generally after the first stage drawing (before redrawing)
Or the stage after the second-stage redrawing process (before the ironing process) is suitable, and in some cases, it may be applied in the middle of the ironing process of two or more stages. Furthermore, the heat treatment may be performed twice or more in the middle of DI processing.

[0052]

【Example】

Example 1 300 obtained by using an ingot obtained by the DC casting method
Aluminum alloy base plate made of 4 alloy and having a thickness of 0.3 mm, aluminum alloy base plate made of 5182 alloy and having a thickness of 0.3 mm, which was also obtained by using an ingot obtained by the DC casting method, and continuous casting An aluminum alloy base plate having a thickness of 0.3 mm and made of a 3004 alloy obtained by applying the twin roll method as a rolling method (CC) was subjected to a chromate treatment of 20 mg / mm ² by a conventional method, A 20 μm thick polyester resin film (glass transition temperature 74 ° C., melting point 239 ° C.) was thermocompression bonded to both sides of each aluminum alloy base plate by hot pressing to obtain a base plate for DI processing (laminate plate). A blank diameter of 145 mmφ is obtained by drawing using these DI processing base plates.
Cup molding with a cup diameter of 87 mmφ was performed. As the lubricating oil in this cup molding, α-olefin based volatile oil having a viscosity of 2 cst was used. Then 240 this cup
Place in a furnace at ℃ for 1 minute, heat treatment and then cool,
After that, redrawing-ironing with a total plate thickness reduction rate of 63% was performed. As the coolant for redrawing and ironing, a nonionic solution coolant prepared by adding a stock solution of fatty acid soap, a surfactant, an antirust agent, etc. to pure water at a concentration of 2% was used. In the ironing process, various die shapes were changed and experiments were conducted. In addition, as a comparative example, an experiment was performed even when the heat treatment was not performed.

Table 1 shows the conditions of the die shape, and Table 2 shows the molding results.

[0054]

[Table 1]

[0055]

[Table 2]

No. 1 to No. 10 is an example of a laminate plate using a 3004 alloy DC material conventionally used for DI cans as a metal base plate. Of these, Nos. 1, 2, 6, and 7 are examples of the present invention. No. 2 is an example corresponding to the invention of claim 1 with a bearing length of 0 mm, and others are examples corresponding to the invention of claim 2. All of these examples of the present invention showed good DI processability and were able to obtain DI cans of good quality. On the other hand, no. Since 3 and 4 had a sharp edge die shape, weak scratches were generated on the film surface after DI processing. No. No. 5 is a comparative example in which the die half-angle and the die half-angle are too small. No. 8 is an example in which the half angle of the die entrance is too large. No. No. 9 was an example in which the half angle of the die exit was too small, and scratches were generated on the film surface. No. In No. 10, the half angle of the die exit was too large, and thus a slightly large uneven thickness occurred.

On the other hand, No. Nos. 11 and 12 were conventionally unsuitable for DI cans due to the occurrence of galling, etc. 5182
It is an example of the present invention about a laminated board using alloy DC material and 3004 alloy CC material as a metal base plate.
No. 12 has a bearing length of 0 mm and corresponds to the invention of claim 1, No. 12 Reference numeral 11 is an example corresponding to the invention of claim 2. Also in these examples of the present invention, good DI processability was exhibited.

Further, No. 13, No. 14 is 300
This is an example in which DI processing was performed on a laminated plate using the 4-alloy DC material without heat treatment, and in these cases, cracks occurred in the resin film.

Example 2 Using the same DI processing blank plate (laminate plate) as in Example 1, various DI processing experiments were conducted after the drawing process and before the redrawing process by changing the heat treatment conditions of the cup. Die conditions for drawing are: inlet half angle θ ₁ = 8 °, outlet half angle θ ₂ = 5 °,
The bearing length L = 0.5 mm, the intersections P ₂ and P ₃ of the bearing portion with the inlet half angle and the outlet half angle have a radius of curvature D = 0.
5 mm. All other conditions were the same as in Example 1.
Table 3 shows the heat treatment conditions and the results of examining the DI moldability.

[0060]

[Table 3]

No. 15-No. No. 18 is an example of the invention in which the heat treatment under the conditions specified in claim 4 was performed, and in any case, good moldability was exhibited and a DI can of good quality could be obtained. No. No. 19 is an example in which heat treatment is not performed, No. 19 20 is an example in which the temperature of the heat treatment was low,
In all cases, the ironing process caused cracks in the resin film. No. In the example of No. 21, the workability was good, but the temperature of the heat treatment was too high, so that the film had a foamy appearance defect. No. In the example No. 21, the temperature of the heat treatment was appropriate, but the heating time was too short, so cracking of the film occurred due to the ironing process.

Example 3 In Example 1, No. 3 was excellent in DI processability. 1,
Under the conditions of No. 2, the lubrication method was changed, DI processing was performed, and the subsequent cleaning property was evaluated. That is, the can after DI processing was spray-washed at a hot water temperature of 70 ° C for 30 seconds and then 200 ° C.
After drying with hot air for 3 minutes, the wettability was evaluated by an ink test. The results are shown in Table 4. In Table 4, the lubrication methods A and B are as follows. Lubrication method A: Cup forming (drawing); α-olefin-based volatile oil with a viscosity of 2 cst Redrawing-ironing; concentration 2% nonionic solution coolant Lubrication method B: cup forming (drawing); synthetic ester with concentration 30% Emulsion re-squeezing-ironing; concentration 4% synthetic ester emulsion

In Table 4, No. 1A, No. Two
A is No. 1 of the first embodiment. This is an example in which the lubrication method A is applied to conditions 1 and 2, and No. 1B, No. Nos. 2B and 2B of Example 1, respectively. An example in which only the lubrication method is changed to B under the conditions of 1 and 2 will be shown.

[0064]

[Table 4]

Although the DI processability was good with any of the lubricating methods, No. 1A, 2A
Showed good detergency, but N processed by lubrication method B
o. Nos. 1B and 2B had poor cleaning properties, and repelled in the ink test.

[0066]

EFFECTS OF THE INVENTION According to the method for producing a drawn and ironed can of the present invention, a DI can is processed including ironing with a plate thickness reduction rate of 30% or more for a laminated plate in which a resin film is previously laminated on a metal base plate. Even if it is applied, a DI can with good appearance quality can be obtained without cracking, scratching, peeling, or clouding of the resin film. Therefore, the production of DI can using a laminated plate is practical. It has become possible to put it into practical use in a mass-production manufacturing process. And since the laminated plate is used in this way, the painting of the DI can after molding is not required, and the cost of the painting process can be reduced, and the volatile lubricant that can be easily removed can be used as the lubricating oil. Therefore, the cost of the cleaning process can be reduced, and along with that, the heat and exhaust gas discharged in these processes can be reduced, which is advantageous in terms of health and safety. In addition, DI for laminated board
Since the metal base plate itself is not required to have excellent ironing workability due to the processing, even if an aluminum alloy is used as the metal base plate, the conventional 3004
Alloy is not limited to the Al-Mn-Mg-based alloy (3000 series alloy) represented by the 3104 alloy, other aluminum alloys can be used, and the flexibility of aluminum alloy selection is expanded. For example, it becomes possible to use an aluminum alloy, such as 5182 alloy, which has low ironing workability but high strength, in a DI can.
It is possible to further increase the strength and thickness of the can, and the manufacturing cost is low, but since the DI processability is poor in the past, it is possible to apply continuously cast rolled materials that have not been used for DI cans. The cost can be reduced by applying such a continuously cast and rolled material.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing a main part of an example of a drawing die used in the present invention.

FIG. 2 is a cross-sectional view showing an enlarged main part of another example of the drawing die used in the present invention.

FIG. 3 is a sectional view generally showing a conventional general drawing die.

4 is an enlarged cross-sectional view showing a main part of the conventional die for drawing shown in FIG.

[Explanation of symbols]

1 Die 3 Bearing part 4 Approach part 5 Release part θ ₁ Half angle of entrance θ ₂ Half angle of exit P ₁ , P ₂ , P ₃ Intersection L Bearing length

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B32B 15/08 B32B 15/08 F

Claims (7)

[Claims] 1. A method for producing a drawn and ironed can by subjecting a metal base plate having a resin film laminated on its surface to drawing, redrawing and ironing, to produce a drawn and ironed can. , The die inlet half angle is within the range of 3 ° to 20 °, and the die outlet half angle is within the range of 1 ° to 20
Ironing with a plate thickness reduction rate of 30% or more is performed by using a die in which the intersection point of the inlet half angle surface and the outlet half angle surface is a curved surface with a radius of curvature of 0.1 mm or more. A method for producing a squeezed ironing can, which comprises applying the squeezed iron. 2. A method for producing a drawn and ironed can by subjecting a metal base plate having a resin film laminated on its surface to drawing, redrawing and ironing to obtain a drawn and ironed can. , The die inlet half angle is within the range of 3 ° to 20 °, and the die outlet half angle is within the range of 1 ° to 20
Within the range of °, and between the surface forming the inlet half angle and the surface forming the outlet half angle, there is a bearing portion substantially parallel to the center axis of the die, and the intersection point of the surface forming the inlet half angle and the bearing portion, And a die in which the intersection of the surface forming the exit half-angle and the bearing portion is each formed by a curved surface having a radius of curvature of 0.1 mm or more, and ironing is performed at a plate thickness reduction rate of 30% or more. Squeeze ironing can manufacturing method. 3. The method of manufacturing a drawn and ironed can according to claim 1, wherein the drawing is performed in the first step by using a volatile lubricating oil. A method of manufacturing a squeezed and ironed can. 4. The method for producing a drawn and ironed can according to claim 1, wherein a thermoplastic resin is used as the resin film, and after the drawing process, before any end of the ironing process. At
5 or more above the glass transition temperature of the thermoplastic resin and above the melting point
A method for producing a squeezed ironing can, which comprises performing a heat treatment for 5 seconds or more at a temperature within a range of 0 ° C. higher. 5. The method of manufacturing a drawn and ironed can according to claim 4, wherein the heat treatment is performed after completion of drawing and before redrawing. 6. The method of manufacturing a drawn and ironed can according to claim 4, wherein the heat treatment is performed after the end of redrawing and before the ironing. 7. The method for manufacturing a drawn and ironed can according to claim 4, wherein the heat treatment is performed at a temperature equal to or higher than the melting point of the thermoplastic resin, followed by cooling to a temperature equal to or lower than the melting point, and subsequent processing. , Squeezed ironing can manufacturing method.