JPH02191793A - Calendering process - Google Patents

Abstract

PURPOSE:To provide a calendering process intended to prevent continuous forms from breakage, so designed that when a continuous form with joints is to be passed between a pair of calender rolls, the pressure contact force of said pair of calender rolls is reduced at the time of passing the joints. CONSTITUTION:When a continuous form made by jointing a plurality of web through the superposition or pressure contact of the adjacent ends is to be calendered by passing it between a pair of calender rolls with one fixed and the other put to pressure contact therewith, the pressure contact force of said pair of calender rolls is reduced at the time of passing the joints of the continuous form between said pair of rolls.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a calendaring method for smoothing a calendar material such as a magnetic recording tape.
The present invention relates to a method for calendering a calendered object having the following properties.

(Prior Art) In order to smooth the surface of a web-like calendered object made of paper, square film, etc., calendering, in which the calendered object is passed between a pair of calendar rolls, is widely practiced. ing.

For example, in a magnetic recording tape, a magnetic coating liquid containing magnetic particles (magnetic powder) and a binder is coated on a non-magnetic support to form a magnetic layer, and then orientation treatment is performed as necessary. After that, the magnetic layer is dried, and then the above-mentioned calendar linking is performed to smooth the surface of the magnetic layer. These calendarers use one calendar roll (fixed roll) fixed in a predetermined position and the other calendar roll (pressure roll) that is pressurized toward the calendar roll to process the object to be calendered. This is generally carried out by holding and transporting the material under pressure and heat.

By the way, the object to be calendered that is passed between the pair of calender rolls mentioned above may be formed by joining a plurality of webs by overlapping or abutting their ends, so that they are continuous in the longitudinal direction. When calendering an object to be calendered that has such joints, it is necessary to prevent the adhesive from being squeezed out of the joints and to prevent wrinkles from forming in the web due to applying pressure to thick joints. Second, when the joint passes between the calender rolls, the pressure roll of the pair of calender rolls is released from the pressing position.

The pressure rolls that have retreated from the pressure position return to the pressure position where they apply pressure to the object to be calendered again after the joint passes between the rolls.

(Problem to be Solved by the Invention) However, when the pressure roller is moved when passing through the joint to reduce the pressure applied to the joint as described above, it tends to take time to move the pressure roller. There is a disadvantage that the non-pressurized portions before and after the joint tend to increase. Furthermore, although a plurality of pairs of calender rolls are normally provided along the conveyance path of the object to be calendered, the rotational speed of the pressure roller is insufficiently controlled when the pressure roller is returned from the retreated position to the pressurized position. is the same as the rotational speed of the adjacent calender roll,
There also arises the problem that the object to be calendered is cut without cooling.

The present invention has been made in view of the above-mentioned problems, and provides a method for calendaring a long object to be calendered with joints a, which can minimize the non-pressurized portion and prevent the occurrence of cutting, etc. The purpose is to provide the following.

(Means for Solving the Problems) In the calendering method of the present invention, a pair of calender rolls are arranged side by side in a substantially horizontal direction, the position of one calender roll is fixed, and the other calender roll is The method is characterized in that the pressurizing force is applied toward the other calender roll, and when the joint portion of the calendered object passes between the pair of calender rolls, the pressurizing force on the other calender roll is reduced.

Note that "reducing the pressure force when the joint part of the object to be calendered passes" means that the pressure force is reduced while the joint part passes between the calender rolls, and specifically: means a control in which the pressurizing force is reduced just before the joint portion reaches between the calender rolls, and the pressurizing force is restored after the joint portion has completely passed between the calender rolls.

(Function) According to this calendering method, the pressure applied to the joint is reduced by reducing the pressure applied to the other calender roll (pressure roll), so the pressure roll is moved. Compared to conventional methods, it is possible to improve responsiveness and reduce unpressurized areas before and after the joint.

In addition, in this method, the pressure can be restored gradually, and there is no need to change the rotation speed of the pressure roll between pressurization and depressurization, so speed control is easy, and the object to be calendered is Cutting can be prevented.

Note that the method of the present invention cannot be carried out well if the calender rolls are arranged side by side in the vertical direction.

In other words, if the upper roll of the calendar rolls lined up vertically is the pressure roll, even if the pressure is reduced, the pressure reduction effect on the joint will be small because the roll itself has a large weight, and the lower roll will be the pressure roll. If it is a roll,
When the pressure is reduced, there is a large gap between the roll and the upper roll.
Responsiveness deteriorates. Therefore, as mentioned above, the calender rolls used in this method must be arranged approximately horizontally, and here, being approximately horizontal means that the two calender rolls must be aligned to the extent that the above-mentioned disadvantages do not occur during depressurization. This means that they are lined up in the horizontal direction.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of a calendaring device implementing a calendaring method according to an embodiment of the present invention.

A magnetic recording tape 1 having a thickness of 20 μm, which is a calendered product in which a magnetic layer is formed on a non-magnetic support, has a pair of first calender rolls 10 and a second calender roll disposed in parallel in the vertical direction. By sequentially passing between the pair 20 and the third pair of calender rolls 30 and being held and conveyed,
A surface smoothing process is performed. The six calender roll pairs 10, 20.30 include a left fixed roll If, 21.31 whose position is fixed, and the fixed roll 1.
1, 21. It is arranged adjacent to the right side of 31, and the pressurizing means 13
．． According to 23.33, n1 fixed roll II, 21.31
It consists of pressure rolls 12, 22 and 32 which are pressurized towards. The diameters of the fixed rolls 11, 21°31 and pressure rolls +2,22,23 are 200111111
% weight is 500 Kg, surface material is 545C surface HC
rMetsuki G11l polished finish, shown in Figure 1! 1′
- Always 11! The feeding speed of the magnetic recording tape 1 of i is 30
0 rrL/min, the fixed roll l 1. ,2
The pressing force by +, , 31 and the pressure roll 12, 22, 32 is 300 K9/art.

By the way, the magnetic recording tape 1 is formed by joining a plurality of webs with their ends overlapped,
The three pairs of calender rolls 0.20.30
, 22, 32 are no longer pressurized by the pressurizing means 13, 23, 33, so that the pressing force on the magnetic recording tape 1 is reduced. That is, the second
As shown in the figure, the ends of the plurality of webs IA constituting the magnetic recording tape 1 are joined to each other over a length of 50 m5+l via a blue tint 2, and this joined part IB
The thickness is 150 μm. The joint portion IB first passes between the first pair of calender rolls IO, and at that time, the pressurizing means 13 stops applying pressure to the pressurizing roll 12 using a pressure release valve or the like. Therefore, the first pair of calender rolls 10 feeds the joint part IB while lightly touching it, and the calendering process is performed only by the second and third pairs of calender rolls 20,30.

Further, the joint portion IB is connected to the first calender roll pair 1.
When the pressure roller 13 is sent out beyond 0, the pressure means 13 returns to the state of pressurizing the pressure roll 12. Also, the joint part I
When B comes between the second pair of calender rolls 20, the pressurizing means 23 stops applying pressure to the pressurizing roll 22, and the joint part IB is connected to the pressurizing roll 22 and the fixed roll 21. After passing through the pressurizing means 23
The pressure on the pressure roll 22 is resumed. Similarly, regarding the third pair of calender rolls 30, under the control of the pressure means 33, the pressure roll 32 is Pressure on the magnetic recording tape 1 is interrupted.

The timings of pressurization and depressurization of the first calender roll pair 10 are shown by solid lines in FIG. The timing of pressure reduction is shown in FIG. 2 by a dashed line and a dashed line, respectively. Note that each of the above lines indicates the position of the leading end in the conveying direction of the joint portion IB.

As described above, according to the calendering method of this embodiment, the reduction in the pressing force of each pair of calender rolls 10, 20, 30 when the joint portion IB passes is controlled by the pressure roll 1.
2.22.32 instead of moving the pressure roll 12
．． Since this is carried out by stopping the pressurization by the pressurizing means 1.3, 23.33 to 22.32, the responsiveness to the pressurized state and depressurized state of the pressure rolls 12, 22.32 is improved. can be increased. Therefore, the non-pressure time that occurs before and after passing through the joint portion IB for each calender roll pair can be shortened, and the non-pressure portion of the magnetic recording tape 1 can be minimized. In addition, the pressure roll +
2.22.32 hardly changes its position, so the rotational speed can be easily controlled after the pressure is restored, and each calender roll pair 10.20.30
The inconvenience that the magnetic recording tape 1 is cut due to the speed difference does not occur.

Note that the number of calendar roll pairs for carrying out the present calendaring method is not limited to the three pairs described above, but can be any number greater than or equal to one. Furthermore, when there are a plurality of pairs of calender rolls, the pressing force, surface roughness, etc. of the rolls may be made different for each pair of rolls. The degree to which the pressure roll is depressurized when the joint passes through the joint may be determined by +73 u4t as appropriate depending on the material and thickness of the object to be calendered, the type of young coupler used for joining, etc. Furthermore, it goes without saying that the present calendaring method can be used to calendar web-like materials such as paper and various films in addition to the above-mentioned magnetic recording tape. Furthermore,
The method of the present invention is also useful even if the joint is a joint in which both web ends are butt-joined.

(Effects of the Invention) As explained above, according to the calendering method of the present invention, it is possible to reduce the unpressurized parts before and after the connection part, and also to prevent the object to be calendered from being cut. , efficient calendaring can be performed stably and continuously.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a calendering apparatus for carrying out a calendering method according to an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining the state of a pressure roll when passing through a joint. 1...Magnetic recording tape IA...Web 1B...
・Joint portion 2... Adhesive 10... First calender roll pair 1.1, 21.31... Fixed roll 12, 22.3
2...pressure roll 13.23.33...pressure means 20...m2 calender roll pair 30...third calender roll pair

Claims (1)

[Claims] A calendered object formed by joining a plurality of webs by overlapping or abutting their ends so that they are continuous in the longitudinal direction is passed between a pair of calender rolls. In a calendering method for smoothing the surface of an object to be calendered, the pair of calender rolls are arranged side by side in a substantially horizontal direction, the position of one calender roll is fixed, and the other calender roll is placed in the same direction as the one of the calender rolls. A calendering method comprising: applying pressure toward a calender roll, and reducing the pressurizing force of the other calender roll when the joint portion of the web passes between the pair of calender rolls.