JP6595368B2 - Cooling roll and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cooling roll and a manufacturing method thereof, and more specifically, a manufacturing apparatus for various sheets such as synthetic resins and various films, a laminating apparatus used for laminating these various sheets and various films, and the like. It relates to the manufacturing method.

  In general, in a laminate manufacturing apparatus that bonds a synthetic resin film to a base material such as paper, for example, as shown in FIG. 10, a base material 22 fed out from a supply roll 21 is a press roll 23 and a cooling roll 24. Between the press roll 23 and the cooling roll 24, while the molten resin is caused to flow down from the T-die 26 to form a film layer 28. The laminated laminated paper 29 is manufactured by laminating to the base material 22 while cooling.

  As the cooling roll 24, for example, in Patent Document 1, a working fluid (heat carrier liquid) is sealed in a cylinder in which a large number of cooling heat transfer tubes are disposed, and the cylinder is driven to rotate. The structure which cools the surface of the said cylindrical body by repetition of evaporation and condensation of the working fluid in a body is disclosed.

Japanese Patent Publication No. 04-2720

  In the cooling roll of Patent Document 1, the working fluid sticks to the inner peripheral surface of the cylindrical body by centrifugal force due to the rotation of the roll, and the working fluid evaporates by the heat from the film layer on the outer periphery of the cylindrical body. The fluid is condensed and liquefied by contact with a number of cooling heat transfer tubes in the cylindrical body, and the liquefied working fluid sticks to the inner peripheral surface of the cylindrical body again by centrifugal force and evaporates. The load such as the film layer on the outer periphery of the cylindrical body is cooled by repeating the above.

  When the load to be cooled by the cooling roll is a high heat load having a large heat quantity such as a relatively thick sheet having a thickness of about 0.5 mm to 2 mm such as a separator for a lithium battery, for example, a laminate film Thus, it is necessary to cool the cooling roll by rotating it at a low speed as compared with a relatively thin load having a thickness of about several tens of μm.

  In the cooling roll, as described above, the liquefied working fluid is stuck to the inner peripheral surface of the cylindrical body by the centrifugal force due to the rotation of the roll. Therefore, if the cooling roll is rotated at a low speed, the centrifugal force is insufficient. However, the liquefied working fluid does not stick to the inner peripheral surface of the cylindrical body and falls downward, resulting in insufficient cooling capacity.

  The present invention has been made in view of the above points, and it is an object of the present invention to increase the amount of working fluid that can be held on the inner peripheral surface of a cylindrical body constituting a roll and to improve the cooling capacity. And

  In order to achieve the above object, a cooling roll according to the present invention includes a cylindrical body in which a plurality of cooling pipes through which a cooling fluid flows is disposed, and a working fluid that repeats evaporation and condensation is contained in the cylindrical body. In the cooling roll to be sealed, a metal sprayed coating is formed on the inner peripheral surface of the cylindrical body, the surface roughness Ra of the sprayed coating is 30 μm or more, and the thickness of the sprayed coating is 1 mm. That's it.

  The metal spray coating is preferably a spray coating of any of Al, Al alloy, SUS, and zinc.

  According to the cooling roll of the present invention, since the metal thermal spray coating having a surface roughness Ra of 30 μm or more and a thickness of 1 mm or more is formed on the inner peripheral surface of the cylindrical body, The amount of liquid that holds the working fluid can be increased by the sprayed coating on the inner peripheral surface, and thereby the amount of working fluid evaporated from the inner peripheral surface of the cylindrical body can be increased to increase the cooling capacity.

  The manufacturing method of the cooling roll of the present invention includes a cylindrical body in which a plurality of cooling pipes through which a cooling fluid flows is disposed, and a cooling fluid in which a working fluid that repeats evaporation and condensation is enclosed in the cylindrical body In this manufacturing method, a metal film having a thickness of 1 mm or more and a surface roughness of 30 μm or more is formed on the inner peripheral surface of the cylindrical body by thermal spraying.

  According to the method for manufacturing a cooling roll of the present invention, a metal sprayed coating having a surface roughness Ra of 30 μm or more and a thickness of 1 mm or more is formed on the inner peripheral surface of the cylindrical body. The amount of liquid that holds the working fluid can be increased by the thermal spray coating on the inner peripheral surface of the body, thereby increasing the amount of working fluid that evaporates from the inner peripheral surface of the cylindrical body and increasing the cooling capacity. it can.

  The thermal spraying is preferably wire thermal spraying.

  According to the present invention, the inner peripheral surface of the cylindrical body is provided with a metal sprayed coating having a surface roughness Ra of 30 μm or more and a thickness of 1 mm or more. The amount of liquid that holds the working fluid can be increased by the thermal spray coating on the surface, and the cooling capacity can be increased.

It is a schematic longitudinal cross-sectional view of the cooling roll which concerns on one Embodiment of this invention. It is sectional drawing which follows the AA line of FIG. FIG. 3 is a partially enlarged sectional view of FIG. 2. It is a schematic block diagram for demonstrating the conditions which calculate the cooling heat amount of a roll, the feed speed of a product, a liquid retention amount, etc. It is a figure which shows the relationship between the amount of cooling heat of a roll, and the amount of liquid retention. It is a figure which shows the relationship between the surface roughness of a thermal spray coating, and the increase weight (liquid holding amount) of the test liquid. It is a figure which shows the relationship between the surface roughness of a thermal spray coating, and the increase weight (liquid holding amount) of the test liquid. It is a figure which shows the relationship between the surface roughness of a thermal spray coating, and the increase weight (liquid holding amount) of the test liquid. It is a cross-sectional photograph of a sprayed coating. It is the schematic of the manufacturing apparatus of laminated laminated paper.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 is a schematic longitudinal sectional view of a cooling roll according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a partially enlarged sectional view of FIG. FIG.

  With reference to these figures, the cooling roll 1 of this embodiment is a cooling roll used for sheet manufacturing apparatuses, such as the laminate manufacturing apparatus of FIG. 10, said lithium battery separator, etc., for example. The cooling roll 1 includes a cylindrical body 2 with a relatively thin plate thickness and a hollow support shaft 3 that supports the cylindrical body 2. End plates 17 and 18 for sealing the inside of the cylindrical body 2 are fixed to both ends of the cylindrical body 2, and further, the inside of the cylindrical body 2 is sealed to the inside of the cylindrical body 2 from the end plates 17 and 18. The face plates 4 and 5 are fixed.

  The support shaft 3 passes through the centers of both end plates 17 and 18 and the double-sided plates 4 and 5 in an airtight state, and both end portions 3 a and 3 b of the support shaft 3 protrude outward from the cylindrical body 2.

  On one end side of the cylindrical body 2, a cooling water inlet chamber 6 is defined by an inner face plate 4 and an outer end plate 17, and the cooling water supplied from one end 3 a of the hollow support shaft 3 is supported. It is introduced into the inlet chamber 6 as indicated by arrows through a plurality of holes formed along the circumferential direction of the shaft 3.

  On the other end side of the cylindrical body 2, a cooling water outlet chamber 7 is defined by an inner face plate 5 and an outer end plate 18, and this outlet chamber 7 is connected to the other end 3 b of the hollow support shaft 3. The cooling water is discharged as indicated by arrows through a plurality of holes that communicate with each other and are formed along the circumferential direction of the support shaft 3.

  Between the double-sided plates 4 and 5, a plurality of cooling pipes 8 extending in the axial direction of the cylindrical body 2 (left and right direction in FIG. 1) and communicating with the inlet chamber 6 and the outlet chamber 7, respectively, extend along the circumferential direction. It is installed side by side.

  Thus, the cooling water introduced into the inlet chamber 6 from the one end 3 a of the support shaft 3 is distributed to each cooling pipe 8, and the cooling water that has flowed through each cooling pipe 8 passes from the outlet chamber 7 to the support shaft 3. It is configured to be discharged through the other end 3b.

  The inside of the cylindrical body 2 sectioned by the double-sided plates 4 and 5 is in a reduced pressure state and is filled with a working fluid that repeats evaporation and condensation, such as alternative chlorofluorocarbon, naphthalene, and quinoline.

  In such a configuration, when the working fluid sealed in the rotating cylindrical body 2 is stuck to the inner peripheral surface of the cylindrical body 2 by centrifugal force, the working fluid such as a high-temperature resin film that contacts the outer peripheral surface of the cylindrical body 2 is used. The working fluid evaporated by the heat from the cooling sheet is cooled by contact with each cooling pipe 8, and condensed and liquefied. The liquefied working fluid returns to the inner peripheral surface of the cylindrical body 2 again by centrifugal force, and evaporates by heat from the sheet to be cooled, thereby repeating the evaporation and condensation to cool the sheet to be cooled. .

  When the sheet to be cooled has a high heat load such as a relatively thick sheet of about 0.5 mm to 2 mm, for example, the amount of heat is large, so that the cooling roll 1 is driven at a low speed, for example, the feeding speed of the sheet to be cooled. It is necessary to cool by rotating so as to be 40 m / min or less.

  However, in the cooling roll 1, since the liquefied working fluid is stuck to the inner peripheral surface of the cylindrical body 2 by the centrifugal force generated by the rotation of the roll as described above, the cooling roll 1 is rotated at a low speed. Then, the centrifugal force is insufficient, and the liquefied working fluid does not stick to the inner peripheral surface of the cylindrical body 2 and falls downward, resulting in insufficient cooling capacity.

  In this embodiment, in order to increase the amount of liquefied working fluid that can be held on the inner peripheral surface of the cylindrical body 2 even when the cooling roll 1 is rotated at a low speed, that is, to increase the liquid retention amount and increase the cooling capacity, the following is performed. It is configured.

  That is, a metal spray coating 9 is formed on the entire inner peripheral surface of the cylindrical body 2 by thermal spraying.

  Since the thermal spray coating is an aggregate of powder containing fine particles of 0.1 mm or less, the surface shape of the thermal spray coating cannot be obtained by simple machining as shown in the cross-sectional photograph of FIG. 9, for example. Has fine irregularities. Therefore, the surface area becomes larger than the machined surface having the same roughness, and the shape is advantageous for holding the liquid.

  FIG. 9 is a cross-sectional photograph of a sprayed coating having a thickness of 3000 μm formed by Al arc wire spraying, and is a cross-sectional photograph of a test piece of Example 7 described later.

  In order to increase the cooling capacity by increasing the amount of liquefied working fluid retained by the sprayed coating 9 on the inner peripheral surface of the cylindrical body 2, in the present invention, the thickness of the sprayed coating 9 is 1 mm or more, The surface roughness Ra is set to 30 μm or more.

  In order to ensure a required liquid retention amount at low speed rotation, the surface roughness Ra of the thermal spray coating 9 is preferably 50 μm or more.

  The material of the thermal spray coating 9 is not particularly limited as long as it is a metal that can be formed by thermal spraying or an alloy thereof, but is used as a thermal spray material, for example, Al, Al alloy, SUS, zinc, which has a rust prevention ability. In particular, Al is preferable because it has high thermal conductivity and can easily transfer heat to the working fluid.

  Although the method of the thermal spraying process for forming the thermal spray coating 9 is not particularly limited, for example, arc wire thermal spraying can be mentioned, and the thermal spray coating 9 of this embodiment is an Al thermal spray coating formed by arc wire thermal spraying. is there.

  Since the thermal spray coating 9 is a metal coating formed by thermal spraying, it has pores.

  Next, the relationship between the amount of heat generated by the cooling roll and the amount of liquid retained that is the amount of liquefied working fluid held on the inner peripheral surface of the cooling roll will be described.

  As shown in the schematic diagram of FIG. 4, a molten resin is caused to flow down from the T-die 12 between the press roll 10 and the cooling roll 11, and the sheet-like product 13 is manufactured by cooling with the cooling roll 11. In the configuration, the roll diameter of the cooling roll 11 is 700 mm, the plate thickness is 30 mm, the effective surface length is 3000 mm, the temperature of the molten resin raw material is 160 ° C., the product thickness is 0.6 mm, the product width is 2800 mm, the product feed speed The working fluid was R-134a which is an alternative chlorofluorocarbon.

  Based on experimental data and the like in the test apparatus having such a configuration, calculation was performed for the cooling heat amount and the liquid retention amount of the roll.

  In other words, the required amount of cooling heat per unit area is calculated from the product feed speed, product width, product thickness, molten resin material temperature, and product temperature, and the working fluid per unit area is calculated from the calculated roll cooling heat amount. The amount of evaporation was determined and calculated as the minimum amount of liquid to be retained.

As a result, as shown in Table 1, when the product feed rate is 40 m / min, which is a low speed, the cooling heat amount of a preferable cooling roll corresponding to a high heat load is 27.84 kcal / m ² (= 187083 kcal / h). The amount of the liquid retained for obtaining ² is 0.20 kg / m ² .

Furthermore, when the feed rate was 40 m / min, the liquid retention amount when the cooling heat amount of the cooling roll was changed was calculated. The results are shown in Table 2 and FIG.

As shown in FIG. 5, a substantially proportional relationship is established between the cooling heat amount and the liquid holding amount, and the cooling heat amount can be increased by increasing the liquid holding amount.

Assuming that the feed rate is 40 m / min, which is a low speed as described above, and that 27.84 kcal / m ² (= 187083 kcal / h) is assumed as the amount of cooling heat to cope with a high heat load, the working fluid R The liquid retention amount of −134a is required to be 0.2 kg / m ² .

That is, when the feed rate is 40 m / min, which is a low speed, in order to obtain a cooling heat amount of 27.84 kcal / m ² (= 187083 kcal / h) or more which is a preferable cooling heat amount for cooling a high heat load, The liquid retention amount of R-134a is 0.2 kg / m ² or more.

The liquid retention amount 0.2 kg / m ² of R-134a is 0.154 kg / m ² because the liquid density of R-134a is 1.295 g / cm ³ when converted to the case of water described later. Become.

  Next, the relationship between the surface roughness of the thermal spray coating and the liquid retention amount will be described.

  In order to grasp the relationship between the surface roughness and thickness of the thermal spray coating and the amount of liquid retained, the following test was conducted.

  That is, after immersing each of a plurality of test pieces each formed with a thermal spray coating having a different thickness and surface roughness in a test solution such as tap water, the increased weight of each test piece pulled up from the test solution, Each was measured as the amount of liquid retained by the thermal spray coating.

  Specifically, a rectangular SS400 flat plate having dimensions of 100 mm × 50 mm × thickness 6 mm was used as the base material of the test piece. A plurality of test pieces were prepared by performing wire spraying with different spraying parameters on both the front and back surfaces of each flat plate to form Al sprayed coatings with different target surface roughness and surface roughness. The sprayed coating adhering to the side surface of the flat plate was removed with a nylon buff.

  The thermal spraying parameters are air pressure, thermal spraying output, wire supply speed, thermal spraying angle, thermal spraying distance, etc., and these thermal spraying parameters were adjusted to form sprayed coatings having different surface roughness Ra.

  The surface roughness Ra of the sprayed coating of each test piece prepared was measured by a stylus type surface roughness meter Surfcom 130A manufactured by Tokyo Seimitsu at a JIS 1994, cutoff value 2.5 mm × N5 = measurement distance 12.5 mm. Sample No. 9 and 10 only have a cut-off value of 8.0 mm × N3 = measurement distance of 24 mm.

  Moreover, the porosity (%) of the sprayed coating of each test piece was measured.

  Next, the weight of each test piece was measured with an electronic balance, and after each test piece was immersed in the test solution for 60 seconds, it was pulled up, and after 60 seconds, the weight was measured again with the electronic balance to increase the weight before and after immersion. The weight was calculated as the liquid retention amount. When the test piece is pulled up from the test solution, the test solution collected at the lower part of the test piece is tilted so that one corner of the test piece is downward, and given a vibration. went.

  Three types of test solutions were used: tap water, tap water to which 10% by weight of ethanol was added, and tap water to which 20% by weight of ethanol was added.

  The test results are shown in Table 3.

Table 3 shows each sample No. In addition to showing the film thickness (mm), porosity (%), and surface roughness (μm) of the sprayed coating of each test piece, the increased weight (kg / m ² ) after immersion in three types of test solutions Show. In addition, the film thickness has shown the target value of the film thickness in the case of thermal spray coating formation. Further, the increased weight is the increased weight kg per 1 m ² as in the case of the liquid retention amount in Table 1, and corresponds to the liquid retention amount.

  As described above, in the present invention, the thermal spray coating has a film thickness of 1 mm or more and a surface roughness Ra of 30 μm or more. In Table 3, sample No. with a film thickness of 0.25 mm. As a comparative example, Sample No. 1 has a film thickness of 1 mm or more and a surface roughness Ra of 30 μm or more. 2-8 are shown as Examples 1-7, respectively.

  When the comparative example is compared with Example 1, the surface roughness Ra is about 30 μm in all cases. However, in Example 1 where the film thickness is 1 mm compared to the comparative example where the film thickness is 0.25 mm, each test solution The increase in weight, that is, the liquid retention amount is significantly increased to about 1.5 times or more. Therefore, in order to increase the amount of liquid retention and increase the cooling capacity, the film thickness of the sprayed coating needs to be 1 mm or more.

  In Examples 1 to 5, the thermal spray coating has a film thickness of 1 mm, and in Examples 6 and 7, the film thickness is 3 mm. In each of Examples 1 to 7, the surface roughness Ra is 30 μm or more. As shown in Examples 1 to 5 in Table 3, even when the film thickness of the sprayed coating is the same, as the surface roughness Ra increases, any test liquid increases in weight, that is, the liquid retention amount increases. I understand that

  Thus, any test solution of tap water (test solution 1), tap water (test solution 2) added with 10% by weight of ethanol, and tap water (test solution 3) added with 20% by weight of ethanol. Since the liquid retention amount is increased, the liquid retention amount of the working fluid can be increased by increasing the surface roughness Ra of the thermal spray coating even if the properties of the working fluid are different.

  When the surface roughness Ra of the thermal spray coating was changed from 38.2 μm in Example 2 to 49.8 μm in Example 3, the amount of the liquid retained was greatly increased. It has doubled.

  Therefore, the surface roughness Ra of the thermal spray coating is preferably 38.2 μm or more, that is, 40 μm or more.

  FIG. 6 shows the relationship between the surface roughness Ra of the comparative example and Examples 1 to 7 when the test liquid is tap water (test liquid 1), and the increased weight before and after immersion, that is, the liquid retention amount.

  As shown in FIG. 6, when the surface roughness Ra of the thermal spray coating is 30 μm or more, the surface roughness Ra and the liquid retention amount (increased weight) are substantially proportional, and the surface roughness Ra is increased by increasing the surface roughness Ra. It can be seen that the cooling capacity can be increased by increasing the liquid volume.

Further, as described above, when the feed rate is 40 m / min, in order to obtain a cooling heat amount of 27.84 kcal / m ² (= 187083 kcal / h) or more which is a preferable cooling heat amount for cooling a high heat load. The working fluid R-134a has a liquid retention amount of 0.2 kg / m ² or more.

This liquid retention amount is 0.154 kg / m ² as described above when converted to water.

In Table 3, the liquid retention volume of approximately equal tap water to the liquid retaining amount 0.154kg / m ² (weight increase) is 0.151kg / m ² of Example 3, the surface roughness Ra is 49 .8 μm.

Therefore, when the feed rate is 40 m / min and the preferable amount of cooling heat for cooling the high heat load is 27.84 kcal / m ² (= 187083 kcal / h) or more, the surface roughness Ra of the thermal spray coating is 49.8 μm or more, that is, 50 μm or more is preferable.

  In FIG.7 and FIG.8, in each case, the test solution of the tap water (test solution 2) which added 10 weight% ethanol and the tap water (test solution 3) which added 20 weight% ethanol, The relationship between the surface roughness Ra of Examples 1-7 and the increased weight (liquid holding amount) before and after immersion is shown.

  As shown in FIG. 7, in the test solution 2, the surface roughness Ra of the thermal spray coating is 30 μm or more and 50 μm or less, and the rate of increase in the liquid retention amount is large, and as shown in FIG. The surface roughness Ra of the sprayed coating is 40 μm or more and 50 μm or less, and the rate of increase in the liquid retention amount is large.

  In any of the test solutions 2 and 3, since the surface roughness Ra of the thermal spray coating is 40 μm or more and the rate of increase in the liquid retention amount is large, the surface roughness Ra of the thermal spray coating may be 40 μm or more.

  By increasing the surface roughness Ra of the sprayed coating as described above, the liquid retention amount can be increased and the cooling capacity can be increased. Therefore, the surface roughness Ra of the sprayed coating is preferably as large as possible. As the Ra is increased, the necessary film thickness increases, so that a larger film thickness is preferable.

  However, in order to increase the film thickness and surface roughness Ra of the thermal spray coating, the processing time required for forming the thermal spray coating becomes longer, the cost increases, and if the film thickness becomes too thick, there is a risk of peeling. .

  Therefore, the upper limit of the film thickness and surface roughness Ra of the thermal spray coating may be appropriately selected in consideration of cost, peeling, etc., but the film thickness of the thermal spray coating is, for example, 10 mm or less, and the surface roughness Ra. For example, it is good also as 300 micrometers or less.

  The working fluid is not limited to the above R-134a (boiling point: −26.15 ° C.), and other working fluids can be used. For example, R-123 (boiling point: 27.62), which is another alternative chlorofluorocarbon. C), R-124 (boiling point: -12.4 ° C), R-225cb (boiling point: 54 ° C) and the like, and working fluids having a boiling point of 60 ° C or less are preferred. Further, as the lower limit, if the boiling point is too low, the pressure in the roll becomes high when the working fluid is liquefied, and high pressure resistance is required.

In the above embodiment, the cooling heat of the ^{roll, 27.84kcal / m 2 (= 187083kcal} / h) has been described ^as, but not limited to 27.84kcal / m 2 (= 187083kcal / h), 27.84kcal / It may be larger than m ² (= 187083 kcal / h) or smaller.

DESCRIPTION OF SYMBOLS 1 Cooling roll 2 Cylindrical body 3 Support shaft 6 Inlet chamber 7 Outlet chamber 8 Cooling pipe 9 Thermal spray coating

Claims (4)

In a cooling roll comprising a cylindrical body in which a plurality of cooling pipes through which a cooling fluid flows is disposed, and in which a working fluid that repeats evaporation and condensation is enclosed,
A metal spray coating is formed on the inner peripheral surface of the cylindrical body,
The surface roughness Ra of the sprayed coating is 30 μm or more, and the thickness of the sprayed coating is 1 mm or more.
A cooling roll characterized by that. The metal spray coating is any one of Al, Al alloy, SUS, and zinc.
The cooling roll according to claim 1. In a manufacturing method of a cooling roll comprising a cylindrical body in which a plurality of cooling pipes through which a cooling fluid flows are provided, and in which a working fluid that repeats evaporation and condensation is enclosed,
On the inner peripheral surface of the cylindrical body, a metal film having a thickness of 1 mm or more and a surface roughness Ra of 30 μm or more is formed by thermal spraying.
A manufacturing method of a cooling roll characterized by the above. The thermal spraying is wire thermal spraying.
The manufacturing method of the cooling roll of Claim 3.