JPH04319048A - Manufacturing device of web-form metal foil - Google Patents

Abstract

PURPOSE: To provide an apparatus capable of manufacturing a metal foil having a desired thickness or thicness and homogeneous quality without changing a nozzle structure and also without using an expensive starting material. CONSTITUTION: A space 9 between a nozzle 4 and a substrate 3 is connected to a vacuum chamber 10, a molten material is sucked toward the substrate at a constant, satisfactorily high pressure with the aid of a vacuum established in the space 9, and interface layers of air accompanying the substrate is displaced. The space between the nozzle 4 and the substrate 3 is communicable with a pressure chamber instead of pressurizing by vacuum 10, and the molten metal supplied through the nozzle is pressurized against the substrate.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention comprises a movable cooled substrate and a nozzle ejecting a short distance from this substrate, through which molten material is ejected onto said substrate to form a metal foil. The present invention relates to an apparatus for producing a web-like metal foil from a molten starting material, which is cooled by cooling.

0002

BACKGROUND OF THE INVENTION A device of the above type is already known, for example from US Pat. No. 4,142,571. Conventional devices have nozzles oriented toward the circumference of a rotating roller or drum, the nozzle openings arranged at a short distance from the circumference through slotted nozzle channels connecting the nozzle openings with the reservoir. , connected to a reservoir for heated molten metal material located above the nozzle. The reservoir is connected to a pressure source which can be used to expel and cool molten material from the reservoir through the nozzle channel and nozzle opening onto the circumferential surface to form the metal foil.

It is known that the quality of the metal foil manufactured by the so-called planar flow casting technique described above greatly depends on changes in the cooling cycle of the melt, and varies due to changes in the cooling cycle. Therefore, in order to achieve the desired uniform foil quality, it is important to perform the melt cooling cycle under conditions that are as constant as possible. In this case, an important element is the intervening layer of air, which clings to the substrate and can impede the cooling cycle and thus favor the formation of quality-impairing air pockets between the melt and the substrate. There is sex. In order to prevent or minimize the risk of quality deterioration caused by such air pockets, the presence of air must be eliminated;
This displacement is achieved in conventional devices, in part by the proximity of the nozzle opening to the substrate, and in part by the pressure of the molten material forced from the nozzle opening to the substrate. For a given nozzle configuration (slot width of the nozzle channel and nozzle opening), the pressure of the melt on the substrate, eliminating any intervening layer of air, essentially depends on the pressure applied to the molten material in the reservoir, so that the desired The applied pressure must be maintained above a predetermined minimum pressure level in order to achieve air exclusion of . Also, for a given nozzle structure, the applied pressure will affect the amount of melt forced out and ultimately the thickness of the finished foil, so to ensure a uniform foil thickness The pressure must be kept as constant as possible.

However, a problem inherent in conventional devices is that it is difficult to prevent pressure fluctuations associated with refilling the reservoir, for example, which cause foil thickness fluctuations. Another problem inherent in conventional equipment is that it is simply not possible to produce metal foils with thicknesses below a given value, for example 50 μm. As explained above, the thickness of the metal foil for a given nozzle configuration depends essentially on the pressure applied to the molten material in the reservoir, which determines the amount of molten material that is extruded. Increasing the amount of molten material dispensed will increase the foil thickness, while decreasing the amount of molten material dispensed will decrease it at the same rate. Therefore, when switching the equipment from producing metal foils of a given thickness to producing other thinner metal foils, the applied pressure (
and the amount of molten material poured out) must be correspondingly reduced. Such a reduction in pressure also reduces the pressure of the melt on the substrate at the same time, eliminating the intervening air bath, resulting in a reduction in the pressure between the molten material and the substrate, which inhibits the cooling process and impairs the quality of the finished foil. The risk of air pockets between the parts increases. To prevent the pressure of the reduced melt on the substrate from being less than that required to achieve the desired air exclusion as described above, the melt pour volume must be adjusted to the desired foil. Modifications to the nozzle structure (ie, nozzle channels and nozzle apertures with reduced slot widths) are required to allow the thickness to be reduced to suit. However, the nozzle structure with small slot width of the nozzle channel and nozzle opening is very sensitive to the purity of the molten starting material, and also requires the purity of the molten starting material very much, so the molten starting material sticks to the passageway. It must be of high purity and free of large-sized impurities so that it can pass through the nozzle channel and nozzle opening without clogging the passageway. Therefore, when using conventional equipment, it is possible to obtain a film of less than 50 μm, e.g.
It is not possible to produce metal foils with a thickness of 0-20 μm.

[0005] One object of the invention is therefore to propose a device of the type described in the preamble, which can achieve desired thicknesses (eg , 50 μm) or thin (e.g. 10-20 μm) and of uniform quality.

Another object of the invention is to produce extremely thin (10- The object of the present invention is to devise an apparatus of the type described above which makes it possible to produce metal foils (20 μm).

[0007]

[Means, structure, and effects for solving the problems] These and other objects are such that the space formed between the base body and the nozzle can communicate with a vacuum chamber or a pressure chamber, and the space can be supplied through the nozzle. This is achieved in accordance with the invention by providing an apparatus of the above-mentioned type with the feature that the molten material is drawn in or pressed through a vacuum or pressure chamber and placed in contact with the substrate.

[0008] Therefore, it is necessary to maintain a sufficiently high and constant melt pressure, that is, melt pressure, on the substrate by means of a pressure difference formed in the space between the substrate and the nozzle by a vacuum chamber or a pressure chamber. is possible, and this melt pressure is completely independent both of the amount of melt material fed through the nozzle opening and of the pressure fluctuations that can occur in the incoming melt. The constant melt pressure formed by the pressure difference produces a metal foil with uniform and excellent surface quality, and at the same time increases the contact efficiency between the melt and the substrate, thereby contributing to the cooling cycle of the melt Forms very good prerequisites. Another advantage is that the melt pressure on the substrate can be kept constant regardless of the amount of melt supplied, and different, i.e. both thick and thin metal foils can be This means that it can be manufactured without changing the structure (slot width of the channel and nozzle opening). Therefore, very thick metal foils, e.g. 50 μm or more, and very thin metal foils, e.g. 10-20 μm, can be manufactured with one and the same nozzle structure. In particular, the slot width of the nozzle channel and nozzle opening is very large, for example, on the order of 2-3 mm, which allows the nozzle to be very thin (10-20 μm).
The production of metal foils is less or not influenced at all by the purity of the starting materials.

Other practical and advantageous embodiments of the device according to the invention are furthermore provided with the features set out in the appended claims.

The present invention will now be described in more detail with reference to the accompanying drawings.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a device according to the invention, a part of which is shown diagrammatically, is generally designated by the reference numeral 1. The device 1 comprises a cooled movable base body, which in the illustrated embodiment consists of a roller rotating about a horizontal axis in the direction of arrow A, or the circumferential surface of a drum 3, or a casting surface 2. Upper nozzle lip part and lower nozzle lip part 4a and 4b
A nozzle 4 with
a, and the nozzle channel discharges from a slot-shaped nozzle opening 4c (slot width 2-3 mm) facing the circumferential surface 2. The nozzle channel 5 receives the molten starting material 7, e.g.
communicates with the metal scrap storage tank 6 and extends beyond the storage tank 6;
A rear part 5b is provided which is closed via an openable hatch or door 8.

As is clear from FIG. 1, the nozzle 4 is arranged such that the nozzle channel 5 is inclined slightly upwardly toward the roller 3 with respect to the horizontal plane, as indicated by the angle of inclination α shown in the rear region of the nozzle. Ru. The nozzle 4 further has a nozzle opening 4c located in a region and level below the horizontal rotational axis (not shown) of the roller 3, that is, in a region located in the fourth quadrant of the coordinate system having the rotational axis of the roller as the zero point. It is arranged so that it can be poured at a very short distance from the circumferential surface 2 (approximately 0.3 mm at the lower nozzle lip portion 4b and upper nozzle lip portion 4a).

In order to be able to feed the molten material 7 by gravity through the inclined nozzle channels 5, 5a from the storage tank 6 to the nozzle opening 4c, the storage tank 6 is arranged such that the molten material surface of this storage tank is above the nozzle opening 4c. It continues to fill so that it is at level (h). When the storage tank 6 is emptied, the molten material surface sinks until this surface is at the same level as the nozzle opening 4c (i.e. h
In order to prevent sinking to 0), the storage tank 6 is arranged in such a way that it is filled with fresh melted material from a tiltable melting furnace (not shown) arranged above the storage tank.

As is clear from FIG. 2, which schematically shows the area of the enlarged nozzle opening 4c, there is a gap between the front end of the lower nozzle lip 4b and the circumferential surface 2, which communicates with the vacuum chamber 10.
Alternatively, a space 9 that can communicate is provided. In the illustrated embodiment, the space 9 is formed as an elongated, slot-like structure with a substantially constant slot width (approximately 0.3 mm) over the entire axial length. A slot width equal to that of the space 9 (i.e., about 0.3 mm) is provided between the peripheral surface 2 and the front end of the upper nozzle lip portion 4a.
) is further provided with a slot-like elongated space 11. The molten material 7 is passed through the entire passage of the channel 5 from the storage tank 6 to the nozzle opening 4c at a temperature below the melting point of the material (for example 950
A heating device 12,
For example, glow canthal tubes are provided in both the upper and lower nozzle lips 4a and 4b, which glow canthal tubes prevent the molten material from cooling before being poured out of the nozzle 4.

FIG. 3 shows a dispensing section of a nozzle according to another embodiment of the invention, with the primo symbol added for clarity.
The same reference numbers have been used for corresponding parts. The nozzle 4' of FIG. 3 thus comprises an upper nozzle lip 4a' and a lower nozzle lip 4b', which define a nozzle opening 5' therebetween. A vacuum chamber 10' is provided between the front end of the lower nozzle lip portion 4b' and the surface 2' of the base body.
A similar elongated space 9' is provided which communicates or is capable of communicating with. The space 9' is different from the space 9 in FIG. 2 in that it forms a tapered part or a V-shaped cross section at the rear (as seen from the moving direction of the base body), that is, the nozzle lip part 4b' and the circumferential surface 2'
The difference is that the distance between the nozzle opening 4c' (slot width) decreases backward from the nozzle opening 4c'. On the other hand, a space 11' between the upper nozzle lip portion 4a' and the surface 2' is formed to have a substantially constant slot width over the entire axial length.

The apparatus 1 shown in FIGS. 1 and 2 produces a web-shaped metal foil 13 in the following manner. The space 9 is arranged in communication with a vacuum chamber 10, and the molten material 7 is fed by gravity via the nozzle channel 5 from the reservoir 6 to the nozzle opening 4c, forming a so-called melt mass 7' in the nozzle opening area. . Due to the pressure filling the space 9 (e.g. 70-90 cm water column), the rear part of the melt mass is sucked into the space 9 and thus onto the circumferential surface 2 at a constant and sufficiently high pressure in the direction of the arrow A (
e.g. at a speed of 30 m/s) to eliminate intervening layers of air associated with a moving circumferential surface. Upon contact with the cooled (approximately 170° C.) substrate, the melt mass is cooled from below and forms a metal foil 13 along the circumferential surface 2; after passing through the space 11, the metal foil is wound up from the circumferential surface and formed into a foil roll. wrapped around.

Using the apparatus 1 metal foils can thus be produced with variable but uniform thicknesses in all individual cases and with a uniform and excellent surface quality. For example, a given thickness (
If a metal foil of 50 μm) is desired, the amount of melt fed is regulated correspondingly, whereas for a thinner (10-2
0 μm), a correspondingly reduced amount of melt is supplied if metal foils are to be produced. The amount of melt supplied in each case is essentially determined by the level difference (h) between the melt surface of the storage layer 6 and the nozzle opening 4c, which level difference is determined by the melting furnace (not shown). It is easy to regulate by controlling the supply of fresh melt from.

In a corresponding manner, a metal foil 13' is produced using the nozzle 4' shown in FIG. An inherent advantage of this nozzle is that the tapered cross section of the space 9' faces towards the circumferential surface;
The vacuum in the space 9' does not need to be as great as the vacuum in the space 9 to achieve the intended sufficiently high melt pressure on the circumferential surface 2', since it produces a pressure component that increases in the rearward direction from the nozzle opening 4c. do not have. In the same way as the nozzle 4 is used, the nozzle 4' can serve to produce a metal foil of varying but uniform thickness in each individual case and of uniform and excellent surface quality. For example, by feeding a predetermined matched amount of molten material, a metal foil with a thickness of about 50 μm can be produced, whereas a thinner metal foil, for example on the order of 10-20 μm, is produced by keeping the quantity at a correspondingly lower level.

Finally, in order to press the melt against the substrate at a constant pressure, the apparatus of the present invention includes a pressure chamber between the nozzle and the substrate instead of the vacuum chamber described above and particularly shown in the drawings. It should be noted that it is possible to provide Ideally, the pressure chamber should be arranged in front of the melt supplied by the nozzle (seen in the direction of movement of the substrate). According to the invention, therefore, a constant high melt pressure on the substrate is created by the device between the nozzle and the substrate;
It is formed by a pressure difference achieved through a space that can communicate with a vacuum chamber or, as described above, a space that can communicate with a pressure chamber.

As is clear from the above description, both the structure and the mode of operation are extremely simple and the cheapest possible without the risk of clogging the nozzle channel and/or nozzle opening due to particles present in the starting material. material,
For example, an extremely thin metal foil (10-2
It is possible according to the invention to produce both thick and thin metal foils from molten starting materials using equipment capable of producing 0 μm).

The invention is not to be considered as being limited to what has been described above and shown in the drawings, and many modifications may be made without departing from the spirit and scope of the appended claims.

[Brief explanation of drawings]

FIG. 1 schematically shows a partial cross-sectional view of a device according to an embodiment of the invention.

FIG. 2 is a diagram schematically showing an enlarged view of the nozzle opening area of the device of FIG. 1;

FIG. 3 schematically shows an enlarged view of the nozzle opening area of another preferred embodiment of the device according to the invention;

[Explanation of symbols]

1　Device 2 Surrounding surface 2' Surrounding surface 3 Roller 4 Nozzle 4' Nozzle 4a Upper nozzle lip part 4a' Upper nozzle lip part 4b Lower nozzle lip part 4b' Lower nozzle lip part 4c Nozzle opening 4c′ Nozzle opening 5 Nozzle channel 5' Nozzle channel 5a Front end 5b Rear part 6 Storage tank 7. Molten material 8 Door 9 Space 9′ space 10 Vacuum chamber 10' Vacuum chamber 11 Space 11' Space 12 Heating device 13 Metal foil 13' Metal foil

Claims (9)

[Claims] 1. A movable cooling substrate (2; 2') and a nozzle (4; 4') discharging a short distance from this substrate, through which melting is carried out to form a metal foil. Apparatus for producing a web-like metal foil from a molten starting material (7), in which the material is discharged onto said substrate and cooled, said nozzle (4; 4') and said substrate (2; 2') A space (9; 9') is provided between the substrate and the molten material supplied from the nozzle to form a pressure difference between the substrate and the molten material. A manufacturing device characterized in that it can communicate with a vacuum chamber (10; 10') or a pressure chamber so as to press it. 2. Manufacturing device according to claim 1, characterized in that the space (9:9') is elongated and its longitudinal axis is substantially parallel to the base body. 3. The manufacturing apparatus according to claim 2, wherein the space (9') is tapered in a direction away from the opening (4c') of the nozzle. 4. The manufacturing apparatus according to claim 1, wherein the base body (2') consists of a rotating roller or a circumferential surface of a drum (3). 5. The manufacturing apparatus according to claim 4, wherein the nozzle (4; 4') is arranged at a level below the rotational axis of the roller. 6. The nozzle (4; 4') comprises an upper lip part (4a; 4a') and a lower lip part (4b; 4b'), which lips are attached to the base body (2; 2'). A oriented nozzle opening (4c; 4c') is formed and the vacuum chamber (1
6. The space (9; 9'), which can communicate with the base body (0; 10'), is arranged between the base body and the lower lip part. The manufacturing equipment described. 7. The distance between the base body (2:2') and the lower lip part (4b; 4b') is smaller than the distance between the base body and the upper lip part (4a; 4a'). The manufacturing apparatus according to claim 6, characterized in that: 8. Both the upper lip and the lower lip are provided with a heating device (12; 12') for maintaining the nozzle (4; 4') at a temperature above the melting temperature of the starting material. The manufacturing apparatus according to claim 6 or 7. 9. The part of the channel arranged towards the storage tank (6) has a rear part which extends beyond the storage tank and is closed via an openable hatch or door (8). The manufacturing apparatus according to any one of claims 1 to 8, characterized in that: