JP2007271147A - Sheet drying machine, and sheet forming device including it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet drying machine and a sheet forming device capable of suitably suppressing slackness of a sheet in a changing environment of a temperature situation and a humidity situation. <P>SOLUTION: The sheet drying machine 3 is provided with a conveyance path 21 carrying out conveyance of a sheet, and a plurality of support guides 25 supporting the sheet during conveyance in the conveyance path from its bottom face. At least one rotatable guide roller 27 is included in the support guides. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet dryer and a sheet forming apparatus including the sheet dryer.

  An example of a manufacturing process of a ceramic electronic component is as follows. First, a ceramic paste is thinly applied on a suitable support sheet, and after drying, the support sheet is peeled off to obtain a ceramic green sheet. And if necessary, after printing the electrode layer on the ceramic green sheet, a plurality of ceramic green sheets are laminated to make a sheet laminate, after pressing, cut to the size of the electronic component unit, firing etc. The desired multilayer ceramic electronic component was obtained.

Moreover, as an apparatus for manufacturing the ceramic green sheet as described above, there is one disclosed in Patent Document 1. In such an apparatus, a doctor blade is disposed above a support sheet that is disposed substantially flat, and the ceramic paste is applied in a thin layer form from the doctor blade while feeding the support sheet. Downstream of the paste application unit, a dryer for drying the paste and a sheet winding device are arranged further downstream. In addition, the support sheet and the dried sheet are usually slidably supported with a predetermined tension applied by a tension roller provided upstream of the doctor blade and a tension roller provided downstream of the dryer. .
JP 2004-338413 A

  According to the inventor's research and analysis, in an apparatus for forming a green sheet, the temperature and humidity surrounding the sheet in the dryer placed between the tension rollers and the state of the wind change, and the sheet is blurred when the sheet is conveyed after applying the paste. May cause distortion.

  Accordingly, an object of the present invention is to provide a sheet dryer and a sheet forming apparatus that can stably convey a sheet in an environment where temperature and humidity and wind conditions change.

  In order to solve the above-described problems, a sheet dryer according to the present invention includes a conveyance path that conveys a sheet, and a plurality of support guides that support a sheet that is being conveyed in the conveyance path from its lower surface. The guide includes at least one rotatable guide roller.

  Preferably, the guide roller is driven to rotate in the same direction as the sheet conveyance direction, and / or the guide roller is driven at the same rotation speed as the sheet conveyance speed.

  The guide roller is preferably arranged on the upstream side in the dryer.

  A sheet forming apparatus according to the present invention for solving the same problem includes a sheet dryer according to the present invention described above, a paste coating apparatus disposed upstream of the dryer, and an upstream of the paste coating apparatus. A sheet unwinding device disposed; and a sheet winding device disposed downstream of the dryer.

  According to the above-described present invention, it is possible to stably convey a sheet in an environment where temperature and humidity and wind conditions change.

  The other features of the present invention and the operational effects thereof will be described in more detail with reference to the accompanying drawings.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

  FIG. 1 is a diagram showing an outline of a sheet forming apparatus according to the present embodiment. The sheet forming apparatus 1 includes a sheet dryer 3, a paste coating apparatus 5, a sheet unwinding apparatus 7, and a sheet winding apparatus 9. The paste coating device 5 is disposed upstream of the sheet dryer 3. Further, the sheet unwinding device 7 is disposed upstream of the paste coating device 5, and the sheet winding device 9 is disposed downstream of the sheet dryer 3.

  The sheet unwinding device 7 has an unwinding roller 11 on which a support sheet such as a PET film is wound, and the support sheet unwound from the unwinding roller 11 at the time of sheet forming is the paste coating device 5 or the sheet. Supplied to the dryer 3. The sheet winding device 9 includes a winding roller 13 on which a green sheet provided with a paste is wound on a support sheet.

  A plurality of tension rollers 15 (a pair in the illustrated example) are arranged between the sheet unwinding device 7 and the sheet winding device 9 in the sheet conveyance path. The tension roller 15 is for applying a suitable tension to the support sheet and the green sheet to which the paste is applied. The paste coating apparatus 5 and the sheet dryer 3 described above are disposed between the pair of tension rollers 15, and the support sheet is in a state in which wrinkles are suppressed and a suitable tension is maintained, in the paste coating process. And subjected to a sheet drying process.

  The paste coating apparatus 5 is for applying a paste on a support sheet, and there is no particular limitation on the paste coating mode in the present invention, but as an example of this embodiment, the paste coating apparatus 5 Has a doctor blade 17. In addition, for example, a paste application mode by an application head or printing may be used.

  The sheet dryer 3 includes a conveyance path 21 that conveys a green sheet, a drying chamber 23, and a plurality of support guides 25. The drying chamber 23 has a storage wall for isolating the inside of the storage from the outside. For example, in the present embodiment, the drying chamber 23 has a six-sided storage wall to form a substantially rectangular parallelepiped drying chamber 23. ing. In addition, the drying chamber 23 is provided with an atmosphere adjusting means (not shown) for adjusting the temperature and humidity in the chamber, and the inside of the chamber is a clean room suitable for drying.

  The support guide 25 supports the green sheet being conveyed from the lower surface thereof, and includes at least one rotatable guide roller 27. As a specific example, in the present embodiment, the support guide 25 includes a plurality of guide rollers 27 and a plurality of fixed guides 29. The guide roller 27 is rotationally driven in the same direction as the sheet conveyance direction and at the same speed as the sheet conveyance speed (see also FIG. 2A). On the other hand, the fixed guides 29 are fixed at corresponding predetermined positions. In addition, the plurality of guide rollers 27 and the plurality of fixed guides 29 are collectively arranged on the upstream side and the downstream side in the drying chamber 23, respectively. More specifically, in the drying chamber 23 according to the present embodiment, the drying is completed in an area of about 2/5 from the upstream side (inlet side). This substantial drying area A plurality of guide rollers 27 are disposed in the region 31, and a plurality of fixed guides 29 are disposed on the downstream side of the drying region 31. The guide roller 27 has a roller outer peripheral portion made of metal, thereby obtaining a smooth roller outer peripheral surface.

  Next, the operation of the above-described sheet forming apparatus and sheet dryer will be described. First, the support sheet 33 unwound from the sheet unwinding device 7 is supplied to the paste coating device 5 through the tension roller 15. In the paste coating apparatus 5, the ceramic paste 35 is supplied to a portion between the doctor blade 17 and the support sheet 33, and the ceramic is formed on the upper surface of the support sheet 33 supplied to the paste coating apparatus 5. Paste 35 is applied.

  Subsequently, the support sheet 33 coated with the ceramic paste 35 is transported into the drying chamber 23 of the sheet dryer 3, dried there, and then transported out of the sheet dryer 3 as a ceramic green sheet 37. The sheet is wound around the sheet winding device 9 via the roller 15 and stored in a roll shape.

  Here, according to the study of the present inventor, the sheet forming apparatus and the sheet dryer have the following problems. First, since the paste coating means and the drying means are arranged between the tension rollers, the distance between the tension rollers must be increased to some extent. In addition, the temperature and humidity surrounding the sheet to which the fluid paste containing moisture is applied and the wind conditions change in the meantime. For this reason, there exists a possibility that a sheet | seat may blur or distort. Therefore, some support is required at a portion between the tension rollers including the inside of the sheet dryer 3.

  Therefore, as a comparative example, as a study of the present inventors, first, as a simple support mode, as shown in FIG. 5B, the lower surface of the ceramic green sheet 37 is supported from below by a simple guide 125. be able to. On the other hand, however, the present inventors have examined and concluded that the temperature and humidity surrounding the sheet and the wind conditions change in the dryer, so that a simple support mode is not sufficient. That is, when the paste evaporates in the sheet dryer 3, the temperature of the sheet is lowered by the heat of vaporization, and as indicated by reference numeral 41, the moisture in the dry atmosphere in the drying chamber 23 is formed on the lower surface of the support sheet 33. Condensation. The condensation moves together with the progress of the sheet and is collected in the guide 125 as indicated by reference numeral 43. The water droplets collected to some extent pass over the guide 125 at a certain time, and are conveyed downstream with the sheet as indicated by reference numeral 45, and finally are wound around the sheet winding device 9 together with the sheet without being dried. It will be.

  Therefore, the present inventor has solved the problem described above by a configuration as shown in FIG. In the present invention, the sheet is supported by a rotatable guide roller 27. As a result, first, loosening of the ceramic green sheet 37 between the tension rollers 15 is prevented as an original support effect. In addition, in the present invention, by rotating the guide roller 27, the dew condensation indicated by the reference numeral 41 is difficult to be controlled in the guide roller 27 and is not collected. As indicated by the reference numeral 47, the condensation is indicated by the progress of the ceramic green sheet 37. The guide roller 27 is passed as it is. For this reason, the condensation is collected and prevented from growing into large droplets, and the individual condensation almost dries and evaporates in the sheet dryer 3 and the downstream area, and finally the sheet is wound together with the sheet. The winding device 9 is prevented from reaching and taking up.

  At this time, a part of the condensation adheres to the guide roller 27 and is dried during the rotation of the roller, as indicated by reference numeral 48. In other words, the guide roller 27 not only prevents water collection but also increases the surface area of condensation and promotes drying.

  Further, when the guide roller 27 is rotationally driven in the same direction as the sheet conveyance direction and at the same speed as the sheet conveyance speed as in the present embodiment described above, the dew condensation and the guide roller that proceed with the sheet There is almost no relative speed difference with the outer peripheral surface of 27, the influence of actions such as shearing and viscosity can be suppressed as much as possible, and water condensation can be prevented more reliably.

  Further, according to the study of the present inventor, the occurrence of condensation is considered to be caused by the heat of vaporization due to the evaporation of the paste, and is concentrated not on the entire inside of the drying chamber but on the portion where the evaporation of the paste is completed. Therefore, in the present embodiment, the guide roller 27 is provided only in the substantial drying region 31, and the fixed guide 29 is provided downstream of the drying region 31 that is sufficient only for the original supporting action. For this reason, it is possible to suppress an increase in cost due to driving and a complicated structure while securing a support mode that does not adversely affect the sheet due to changes in temperature and humidity conditions.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

  For example, in the present invention, the tension roller described above is not necessarily required, and a configuration in which the sheet unwinding device and the sheet winding device itself also serve as the tension roller without having an individual tension roller may be employed.

  Moreover, as a sheet dryer, it is not always necessary to clearly have a drying cabinet surrounded by a storage wall. Further, the drying mode is not particularly limited, and can be appropriately selected with respect to various conditions such as active gas injection / forced circulation, temperature profile, and humidity profile.

  In addition, as a configuration of the support guide, in order to further improve the drying efficiency of condensation, a mode in which the surface of the roller is covered with a water-absorbing substance (for example, a porous resin sheet or a water-absorbing sheet), and the surface area is embossed to increase the surface area of the roller In addition, an aspect in which the drying efficiency is increased or an aspect in which the surface is heated with a heating wire may be used.

  It is sufficient that the support guide has at least one guide roller somewhere in the substantially dry region, and the configuration of the remaining support guides other than the guide roller is not particularly limited.

It is a figure which shows the outline | summary of the sheet forming apparatus which concerns on embodiment of this invention. (A) is an enlarged view of the sheet | seat support part which concerns on this Embodiment, (b) is an enlarged view of the sheet | seat support part as a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet shaping | molding apparatus 3 Sheet dryer 5 Paste coating apparatus 7 Sheet unwinding apparatus 9 Sheet winding apparatus 21 Conveyance path 25 Support guide 27 Guide roller

Claims (5)

A conveyance path for conveying a sheet;
A plurality of support guides for supporting the sheet being conveyed in the conveyance path from its lower surface;
The support guide includes at least one rotatable guide roller,
Sheet dryer. The sheet dryer according to claim 1,
The guide roller is rotationally driven in the same direction as the sheet conveying direction.
Sheet dryer. The sheet dryer according to claim 2,
The guide roller is driven at the same rotational speed as the sheet conveying speed.
Sheet dryer. A sheet dryer according to any one of claims 1 to 3,
The guide roller is disposed on the upstream side in the dryer.
Sheet dryer. A sheet dryer according to any one of claims 1 to 4,
A paste coating device disposed upstream of the dryer;
A sheet unwinding device disposed upstream of the paste coating device;
A sheet winding device disposed downstream of the dryer,
Sheet forming device.

Images