JPH04185790A - Method and device for calendering - Google Patents

Abstract

PURPOSE:To prepare a sheet having high surface smoothness and tissue denseness in improved treatment efficiency by feeding the sheet between a pair of rolls contacting with each other at a contact pressure and having different peripheral speeds, respectively, and nipping the sheet between the rolls to calender the sheet. CONSTITUTION:At least one pair of rolls comprising a metal roll 1 and an elastic roll 2 contacting with each other under a contact pressure are successively arranged, and the main rolls are connected to the motors 4 of driving means, respectively, and forcibly rotated. The pair of rolls are rotated by the driving means so that the peripheral speeds of the pair of the rolls are different from each other to form a calendering device. A sheet is fed between the pair of the rolls from the sheet-delivering roll 11 of a sheet-feeding means in the calendering device, and the sheet is nipped between the rolls to calender the sheet, thereby providing the high quality calendered sheet in improved treatment efficiency.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a calendering method for smoothing the surface and densifying the texture of a sheet by compressing the sheet between rolls and applying pressure and temperature, and an apparatus for carrying out the method. Particularly, the present invention relates to an improvement in a calendering method and device that can provide high processing effects.

[Conventional technology]

Calendering is carried out by bringing metal rolls or elastic rolls into contact while rotating, feeding the sheet between these rolls, and squeezing the sheet while applying pressure and temperature. The purpose of this treatment is to smooth the surface of the sheet, increase the tissue density of the sheet, and obtain a sheet with a glossy surface, dense, and firm. In this calender processing device, a plurality of metal rolls and an elastic roll are brought into contact with each other in sequence, and the sheet is passed between these rolls in sequence.In this case, only one of the rolls is driven, and the other rolls are driven. This main drive roll is driven to rotate so that there is no slippage. Therefore, the circumferential speed of each roll is equal and the same as the sheet feeding speed. [Problem to be solved by the invention] In order to enhance the effect of calendering and improve the surface smoothness and fineness of the structure,
It is necessary to further increase the nip pressure and temperature of the rolls. However, when the temperature is increased, especially in the case of an elastic roll, its surface tends to be thermally deformed, making it impossible to obtain sufficient nip pressure. Additionally, if you try to increase the pressure between the rolls and increase the nip pressure, the rolls will be more likely to warp or the surface will collapse.Therefore, there are naturally limits to increasing the nip pressure or temperature. However, if they become excessive, processing accuracy tends to decrease, processing variations tend to occur, and quality deteriorates. It is an object of the present invention to solve the problems and provide a calender processing method with higher processing effects and a processing device for implementing the same. [Means for solving the problems] That is, the present invention achieves the above objects In this method, the sheet is fed between at least a pair of rolls that are in contact with each other with contact pressure, and the sheet is pinched between the rolls to calender the sheet. Roughly speaking, at least a pair of rolls that roll into contact with each other while applying contact pressure, a drive mechanism that rotates the rolls, and a sheet between these rolls are provided. The present invention provides a calender processing apparatus including a sheet feeding means, wherein each of the rolls is a driving roll connected to a drive mechanism and forcibly rotated.

[For production]

As will be described later as a specific example, in the calendering method according to the present invention, when calendering is performed at the same temperature and under the same roll pressure, the surface gloss and thickness shrinkage of the seal are superior to the conventional method. A high treatment effect was observed. This is considered to be due to the following reasons. That is, when a sheet is pressed between rolls, roll pressure is applied to the sheet in the thickness direction thereof, and a rubbing force is applied to the sheet in the surface direction due to the difference in peripheral speed of the rolls. As a result, the resultant force of this roll pressure and rubbing force acts on the sheet. This resultant force is stronger than the roll pressure when there is no rubbing force, and the surface and internal structure of the sheet is compacted by this resultant force, so that the structure becomes dense and the surface becomes smooth. Furthermore, in the calender processing apparatus according to the present invention, each roll is connected to a drive mechanism and is forced to rotate, so that the contacting rolls can be rotated at different circumferential speeds, and the above-mentioned calender processing method can be carried out. [Example] Next, an example of the present invention will be specifically described with reference to the drawings. 1 and 3 show an embodiment of a calendering device according to the invention, in which, as already mentioned, a metal roll l and an elastic roll 2 are brought into contact one after another, and these rolls 1.2
Pass the sheets sequentially between the In the case shown, a total of seven metal rolls l and elastic rolls 2 are brought into contact with each other alternately, and as shown in FIG. It is inserted between the uppermost metal roll 1 and the lower elastic roll 2. Further, this sheet a is successively inserted between the lower rolls 1.2, the lowermost metal roll 1 and the elastic roll 2 above it.
After being pulled out from between, it is wound up on the roll 12 on the winding side. In FIG. 1, the symbol 3.3 represents the roll 1.2.
It shows bearings that hold on both sides, to which a roll pressure P is applied. Further, each roll 1.2 is connected with a motor 4.4 as a driving source for each roll 1.2.
are forced to rotate independently. In the calendering method according to the present invention, the circumferential speed of each roll 1.2 from the upper metal roll 1 to the lowermost metal roll 1 is set to Vl, V2...Vl.
In this case, for example, Vl<V2<...<Vl. FIG. 2 schematically shows how the sheet a is pinched between the rolls 1 and 2. As already mentioned, when the sheet a is pressed between the rolls 1.2, the roll pressure P is applied to both sides of the sheet 1 in the thickness direction, and the circumferential speed of the roll 112 is applied in the surface direction of the sheet a. A rubbing force F is applied due to the difference between A resultant force R of this roll pressure P and rubbing force F is applied to the sheet a. FIG. 4 shows another embodiment of the invention, in which the motor 4 has a single gold tooth and the rotation of the motor 4 is directly transmitted to the lowermost metal roll 1 via a shaft. However, it is sequentially transmitted to the other roll L2 via the sprocket wheels 21, 22 and the sprocket 23. In this case as well, the circumferential speed of each roll 1.2 from the upper metal roll I to the lowermost metal roll 1 is Vl, , V2 .
・In the case of v7, for example, Vl<V2ku...<Vl
Adjust the tooth number ratio of the sprocket wheels 21 and 22 so that Next, specific embodiments of the present invention will be described.
- Contains σFe2O3 powder as a magnetic material, which is Al2
A magnetic paint prepared by dissolving a vinyl chloride-vinyl acetate copolymer dissolved in a solvent together with a fiber such as O3 was applied to the surface of a polyester film. After drying this magnetic tape, a metal roll 1 with a diameter of 180 mrrh and a width of 300 mm is prepared.
Using a calendering device as shown in Fig. 4, which combines elastic rolls 2 and 2, the temperature is 90°C, 1 roll pressure P=
Calendar treatment was carried out under the condition of 350 kg/cm2. In this case, the ratio of the circumferential speed difference between adjacent rollers 1.2, knob (V2-Vl)/VI= (V3-V2)/V2=
(V4-V3)/V3=(V5-V6)/VB= (
The experiment was carried out by changing Vl-V6)/V6 to 0°1.3.5 and 7 (%). Then, the shrinkage rate of the magnetic tape thickness before and after treatment (= (thickness before treatment - thickness after treatment) / thickness before treatment) was measured, and further, using a Nippon Telegraph digital gloss meter, the magnetic tape was The gloss of the paint surface was measured. At the same time, the elongation of the tape in the longitudinal direction (=(reference length of treated surface - reference length after treatment)/reference length before treatment) was measured. These results are shown in Table 1 along with the roll speed difference. Table 1 It is clear from these results that a circumferential speed difference ratio of 1 to 5% is good, and if it exceeds that, the tape begins to elongate. For example, when the peripheral speed difference ratio is 3%, the processing effect is improved by 40% in thickness shrinkage and by 4.3% in gloss compared to the conventional method (peripheral speed difference ratio 0%). In the above embodiment, a method for calendering a magnetic tape has been described, but it goes without saying that the invention ψJ can be applied to general calendering of paper, lubricant film, and the like. [Effects of the Invention] As explained above, according to the present invention, it is possible to improve the effect of calendering without excessively increasing the roll pressure or temperature, and to provide a calendering method that enables sub-quality calendering. equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a front view of a calendering device showing an embodiment of the present invention, FIG. 2 is a schematic diagram showing a state of pressing a sheet between rolls, and FIG. 3 is a side view of the same calendering device. ,
FIG. 4 is a front view of a calendar processing device showing another embodiment. ■... Metal roll 2... Elastic roll 3... Bearing 4... Motor 1],... Delivery roll 12
Winding roll 13.14...Tension roll 21
,． 22... Sprocket wheel 23... Sprocket Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A method in which a sheet is fed between at least a pair of rolls that are in contact with each other with contact pressure, and the sheet is pinched between the rolls to calender the sheet, the circumferential speed of the pair of rolls that are in contact with each other. A calendar processing method characterized by making the numbers different from each other. (2) A calendering device comprising at least a pair of rolls that roll into contact with each other while applying contact pressure, a drive mechanism that rotates the rolls, and a sheet supply means that supplies a sheet between these rolls, wherein each of the rolls is A calendering device characterized in that it is a driving roll connected to a drive mechanism and forced to rotate.