JPS6229068A - Slitter for application of slurry - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of the thickness of an applied slurry, by rotating a roller having an eccentric shaft, to alter the size of the gap between rollers or the width of a slit. CONSTITUTION:Two slitter rollers 10, 10' are provided instead of blades. Comb teeth 16, 16' under the rollers 10, 10' function to position a core material in the middle between the rollers and stably feed a slurry to the rollers. The slitter roller 10 has an eccentric shaft 11, which is rotated by a pulse motor 15 through pulleys 13, 13' and a belt 14. The pulse motor 15 is driven on the basis of the signal of an optical displacement sensor provided immediately over a slitter to detect the thickness of the applied slurry, to adjust the width of a slit to control the thickness of the applied slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a sintered substrate for use in electrode plates for Ni--Cd batteries, which is made by using N1 powder, which is the raw material for the sintered body, and a binder. This invention relates to the structure of a slurry coating slitter for coating a porous plate (core material) with a slurry made by kneading methylcellulose powder (MC powder) and water.

Conventional technology The manufacturing method for sintered electrode plates used in sealed cylindrical Ni-Cd batteries involves coating a slurry of N1 powder, MC powder, and water with Ni plating that has a large number of holes with an aperture ratio of approximately 5o4. After applying it to the Fe core material, it was dried and further coated with H.
The Ni powder is sintered by heating to 900 to 950''C in a furnace with a reducing atmosphere of grade 2 to form a sintered body having a porosity of approximately 80q6 (80% of the apparent volume of the sintered body).
This means that the zero section is covered with pores. μ, an extremely porous sintered body) is formed on the core material (
(Hereinafter, this will be referred to as a sintered substrate). Thereafter, the pores in the sintered body are impregnated with an active material and chemically formed to form an electrode plate.

As is clear from the manufacturing process described above, in sintered electrode plates, the amount of active material impregnated depends on the size of the pore volume in the sintered body, so it is possible to stably produce batteries with consistent performance. For production, it is very important to manufacture a certain sintered substrate. For this reason, various studies have been carried out in the past, but a sufficient solution has not been found due to the problem of variations in the thickness of the sintered body. Needless to say, if the thickness changes (active material This means that the amount of impregnation will vary.The cause of the variation in the thickness of the sintered body is the variation in the coating thickness of the slurry, but here we will explain the coating method using drawings. As shown in Figure 2, a concrete example is shown in which the core material 1 is guided into the coating tank 3 via the guide roll 2, and passed through the slurry 4 stored in the coating tank. , and pull it upward through the guide roll 2' in the tank. At this time, as shown in the figure (passing between the two plate-shaped blades 6 and 6' of the slitter 5,
At this point, the excess slurry 4' applied to the core material 1 is scraped off, and at the same time, the amount of slurry 4' applied to the core material surface is increased to a predetermined thickness.
In other words, it forms.

In the above-mentioned coating process, the coating amount, that is, the coating thickness, is controlled by adjusting the slit width, that is, the interval between the slitter blades 6 and 6'. It goes without saying that the slit width is set at the start of coating, but in reality it is difficult to always maintain a predetermined coating thickness with the slit width set at the start, and the thickness of the sintered body increases as the coating time passes. Phenomena such as gradually decreasing or increasing when newly kneaded slurry is added to the coating tank 3 occur. These phenomena occur due to changes in the viscosity of the slurry 4 being applied or changes in the distance between the slitter 5 and the liquid level of the slurry 4 (h in Figure 2) during application. Specifically, as mentioned above, this appears in the form of variations in coating thickness. Therefore, in order to keep the coating thickness constant, it is necessary to change the slit width in response to changes in the viscosity of the slurry 4, for example. Of course, this is not necessary if the viscosity of slurry 4 does not change, but since slurry viscosity is affected by many factors such as ambient temperature, humidity, particle size of raw material powder, etc. Even if measures such as air conditioning are taken, it is difficult to completely suppress these changes. Therefore, it is necessary to adjust the slit width during the coating process.

Problems to be Solved by the Invention By the way, the above-mentioned adjustment of the slit width must be done manually and at a level of 1/100, and of course it must be done using a measuring device such as a caliper. mosquito,
The reality is that it relies partly on intuition, and only experienced people can achieve high altitudes.

What makes this work even more difficult is the slitter 5.
The structure of As shown in FIG. 3, the conventional slitter has two plate-shaped blades 6 and 6' that ultimately determine the coating thickness. This blade 6.6' is made of stainless steel and has dimensions such as ", LtW,
J3 has 2 degrees each, lOm, 40+n, 350n++
As shown in the figure, the blades 6 and 6' are fixed to the base 8 with screws 9 in such a manner that the longitudinal direction thereof runs along the width direction of the core material. To adjust the slit width, loosen the screw 9.9' and lightly tap the end of the blade 6.6' to measure the size in units of 100 minutes as described above, and then This also ensures parallelism between the blades, but as can be easily understood from the above figures, this work depends on a high level of skill. .6' is often changed due to the force applied when tightening the screw 9.9'.

Measures to Solve the Problem If we consider the reason why it is difficult to adjust the slit width from the structural aspect of the slitter, we will find that the slit cannot be opened unless the blade itself is brought to a freer state by loosening the screw. It was determined that the problem was that the structure was such that the width could not be adjusted. If the slit width could be changed while the blade 6.6' is fixed to the base 8 by some means, the adjustment work would be extremely easy. We have carried out various studies on this point,
A conventional plate-shaped blade 6.6' with an eccentric axis 1
Instead of using a pair of rolls, we devised a method in which the coating thickness is controlled by rotating the rolls and changing the gap between the two rolls, that is, the slit width. Figure 4 explains this principle. In the figure, 1O1l O' is a roll (hereinafter referred to as a slitter roll) that plays the same role as the conventional blade 6.6', and both have the same radius r and are eccentric by a distance e. axis (hereinafter referred to as eccentric axis) 11
, t t'. Both slitter rolls 10.10
' has eccentric axes 11, tt', so for example, if it is initially positioned in the state shown by the solid line with a gap G, it can be moved around this while keeping the positions of the eccentric axes tt, tt' fixed. When it is rotated by an angle α (hereinafter referred to as rotation angle) in the direction of the arrow, it moves to the position shown by the dotted line. As a result, the gap between both slitter rolls 10 and 10' changes to G, and the slit width is adjusted using this movement. As is clear from the figure (as mentioned above, it is not always necessary for both slitter rolls to have the same radius, and it is also possible to adjust the slit width using only the other roll without providing an eccentric shaft on one roll. It is quite possible.

The advantage of this method is that it is not necessary to free the slit roll 1011O' from the base when adjusting the slit width. In other words, the eccentric axes tt and tt' of the slitter rolls to and to' are fixed to the base 1 via roller bearings, etc., so that the slitter rolls 10 and 10' themselves can be moved to the core material side, unlike the conventional way of moving the blades. There is no need to adjust it by moving it closer or further away.

It is extremely simple because it simply rotates the slitter rolls io and to'. Also, how much the slit width changes when the rotation angle α is changed is determined by the radius r and eccentric distance e of the slitter rolls to, to', and there are countless combinations, so there is freedom in slitter design. The degree is extremely large. Another advantage is that the slit width can be adjusted steplessly.

Furthermore, if the two slitter rolls to and to' are fixed to the base, even if the slitter rolls to and to' are rotated, the gap between the two rolls will remain constant at any position in the longitudinal direction. Therefore, variations in coating thickness in the width direction of the core material (in the width direction in FIG. 3) can be significantly suppressed.

Another advantage of adopting such a method is that the slit width adjustment can be easily automated.

As will be described later, when implementing the present invention, the slit width is adjusted in the same way as in the past (rather than relying on manual labor), the coating thickness is detected and the signal is fed back to automatically adjust the slit width. However, in this case, it is difficult to move the conventional long and thin plate-shaped blade smoothly in the direction perpendicular to the core material (W direction in Figure 3), and the drive device is inevitably large-scale. However, if a roll-shaped roll is used as in the present invention, it is extremely easy to rotate it, and all that is required is to apply rotational force to one end of the slit roll l0110' using a small pulse motor. Even if the slitter is a little more complicated than the current slitter, the degree of complexity is not enough to cause a problem.

With the above configuration, the present invention can freely change the coating thickness of the slurry to a prescribed thickness by rotating the slitter roll.

EXAMPLES Next, examples of the present invention will be described. FIG. 1 shows the structure of a slitter for applying slurry according to the present invention, which has two slitter rolls 10 and 10' instead of the conventional plate-shaped blade, as described above. Slitter roll l0110
The lower side of ' has comb teeth 16.16' like the conventional slitter, and the role of positioning the core material at the center of the slitter roll 10.10' is similar to that of the slitter roll l0110'.
It plays the role of stably supplying slurry to the side. The two slitter rolls 10 and 10' are fixed to the base 8 via a bearing 12 equipped with a bearing, but in the embodiment, the slit width is controlled by rotating only one slitter roll IO. The slitter roll 10 has an eccentric shaft 11, but the shaft of the slitter roll lO' is eccentric. Suritsuta Roll 10
The eccentric shaft 11 of is rotated by a pulse motor 15 via a pulley 13, 13' and a belt 14. Although the slit width is automatically controlled, the signal for driving the pulse motor is obtained from an optical displacement sensor for detecting coating thickness installed directly above the slitter. The dimensions of the slitter roll for LO are 40 mm in diameter, 350 mm in length, and eccentric distance tm, while those in LO' are 42 mm in diameter and the same length < 350 mm. Both materials are 5US304
It is. Further, in the case of the present slitter, the slit width is adjusted to change by approximately (l l m) by rotating the slitter roll IO by 10° around the eccentric shaft 11.

Effects of the Invention When the slitter for applying slurry according to the present invention is used to automatically control the coating thickness using the method described above, and when the slit width is manually adjusted using a conventional slitter for applying slurry. When this method was used, the yield of the obtained electrode plates (the number of electrode plates within the specified weight range divided by the number of 5000 plates) was investigated, and it was found that the latter (conventional method) The former was 98.74 while it was 94.64.
The value was shown as follows. In addition, the variation in the method according to the present invention is about 115 compared to the conventional method.From the above points, the method according to the present invention has extremely great industrial value.

[Brief explanation of the drawing]

FIG. 1 shows the structure of a slitter for applying slurry having a slitter roll according to an embodiment of the present invention, in which (a) is a top view, (b) is a sectional view taken along line A-A' in (a), and FIG. FIG. 4 is a diagram showing the principle of slit width adjustment according to the present invention.

Claims (1)

[Claims] A structure comprising two rolls, one or both of which have eccentric shafts, and by rotating one or both of the rolls around the eccentric shaft, the distance between the two rolls is changed to change the coating thickness. A slitter for applying slurry, comprising: