WO2004029361A1

WO2004029361A1 - Extensible paper producing method

Info

Publication number: WO2004029361A1
Application number: PCT/JP2003/012470
Authority: WO
Inventors: Masato Oogimoto; Hideichi Kawasaki; Masatsugu Kato; Hidenori Ogawa
Original assignee: Nippon Paper Industries Co., Ltd.; Hatoh, Nobuhiro
Priority date: 2002-09-30
Filing date: 2003-09-30
Publication date: 2004-04-08
Also published as: AU2003266702A1; AU2003266702A8

Abstract

A moisture-adjusted wet paper sheet obtained by subjecting a sheet-like paper base material to a moisture applicator to adjust its paper moisture to be in a range of 20-50% is passed through a shrinkage applicator that comprises a pair of press rolls consisting of a hard roll having peripherally extending grooves formed in the peripheral roll surface and spaced a predetermined distance from each other widthwise of the roll and a soft roll having a smooth peripheral roll surface and that is designed to rotate the soft roll such that its peripheral speed is lower than that of the hard roll during pressurization, thereby applying shrinkage to the moisture-adjusted wet paper sheet, the latter being then dried. Thereby, an extensible paper that exhibits elongation which is more than 20%, both longitudinally and transversely, can be easily obtained. Moreover, general-purpose paper base material can be used as a sheet-like base material, which is economical.

Description

Specification

Manufacturing method of stretched paper

Technical field

The present invention relates to a method for producing stretched paper suitable for molded paper having a longitudinal elongation of 20% or more and a lateral elongation of 20% or more.

Background art

2. Description of the Related Art Conventionally, as a food or drinking water container, a paper molded article such as a dish made by pressing natural pulp paper or a cup having a cylindrical body and a bottom plate has been known. Such a paper-made product, especially a plate made by pressing, could only obtain a shallow shape due to the inherent elongation characteristics of the paper base.

As a method for producing stretched paper having high elongation characteristics, clupak treatment and creep treatment have been conventionally known. However, since the compaction and crepe treatments are compressed only in the vertical direction, the horizontal direction hardly changes, and only the elongation property is applied to one axis in the vertical direction. Even if stretched paper obtained by these methods is used, the shape of the molded product is limited to a narrow range.

Therefore, in recent years, preforming in the form of corrugated treatment has been performed, and furthermore, a roller made of a hard material and having a rib on its surface and rotating at a high speed, and a smooth surface made of a soft material ¾: A technique for condensing between a pair of rollers rotating at a lower speed and simultaneously imparting vertical and horizontal stretching characteristics has been proposed in Japanese Patent Application Laid-Open No. 11-5099276. I have.

However, the technique described in Japanese Patent Application Laid-Open No. 11-5099276 requires preforming of a corrugated processing form, and has a problem that the manufacturing method becomes complicated. In addition, the elongation characteristics are limited to about 20% in length and 16% in width, and there is a problem that the elongation characteristics are not + min and cannot be applied to deep drawing which requires large elongation.

Another method of producing stretched paper, which can be expected to have large elongation, is to mix fibrous materials made from thermoplastic resin into pulp and heat it. Although a method of imparting elongation properties has been proposed, it is not preferable from the viewpoint of waste disposal and environmental load due to global environmental problems.

Disclosure of the invention

An object of the present invention is to use a general-purpose paper base material, and to easily and economically produce high-strength paper having an elongation property of 20% or more in longitudinal elongation and 20% or more in lateral elongation. It is to provide a manufacturing method of.

An object of the present invention is to provide a pair of press rolls composed of a hard roll in which grooves along the circumferential direction are provided on the roll circumferential surface at predetermined intervals in the roll width direction and a soft roll having a flat roll circumferential surface. The contact length between the hard roll and the soft roll during pressurization is 3 Omm or more and 8 Omm or less, and the peripheral speed of the soft roll is slower than the peripheral speed of the hard roll under pressure. The water content in the paper is 20% to 50% in a shrinkage imparting device that rotates. /. This method is achieved by a method for producing a stretched paper, characterized in that the moisture-regulated wet paper sheet is passed through the sheet to shrink the moisture-regulated wet paper sheet and then dried. According to the manufacturing method, abrasion on the surface of the soft roll is suppressed.

Another object of the present invention is to provide a pair of press ports composed of a hard roll in which grooves along the circumferential direction are provided on the roll circumferential surface at predetermined intervals in the roll width direction and a soft roll having a flat circumferential surface of the roll. The soft roll has a two-layer structure in which a surface layer portion made of a material having excellent wear resistance and an inner layer portion made of a material which is easily deformed under pressure are integrated. Pass the moisture-adjusted wet paper sheet having a paper moisture content of 20% to 50% through a shrinkage imparting device that rotates the soft roll at a lower peripheral speed than the hard roll peripheral speed. Then, the moisture-regulated wet paper sheet is shrunk, and then dried, and is achieved by a method for producing a stretched paper. The effect of imparting shrinkage and the improvement of durability can be achieved.

The soft roll has a surface layer made of a material having a wear resistance of 0.05 cc / 1000 or less, and an inner layer compressed at a pressure of 0.5 MPa. It is made of a material with a compressive deformation of 4% or more when pressed.

The ratio of the thickness of the surface layer portion to the inner layer portion of the soft roll is: surface layer portion: inner layer portion = 5/95: 30/70.

The material of the surface layer part and / or inner layer part of the soft roll is any of polyurethane rubber, chronoprene rubber, tree / lebutadiene rubber, silicone rubber, polysanolefide rubber, trinole rubber, and epichrome / lehido rubber. Consists of

Further, an object of the present invention is to provide a pair of press rolls composed of a hard roll in which grooves along the circumferential direction are provided on the roll circumferential surface at predetermined intervals in the roll width direction and a soft roll having a flat roll circumferential surface. The shrinkage imparting device, which is configured to rotate the soft roll at a lower peripheral speed than that of the hard roll under the pressure of caro, so as to rotate, has a basis weight of 35 g Zm ² to 450 g / water wet paper strength m ² was adjusted to 0. lk NZm~ 2. O k N / range sheet paper substrate at moisturizing apparatus of the paper in the water 2 0% 5 0% of the m This is achieved by a method for producing stretched paper, characterized in that the adjusted wet paper sheet is passed through to give shrinkage to the moisture adjusted wet paper sheet, and then dried.

The moisture applying device is any one of a roll coating system, a printing system, an impregnation system, and a spray system, or a system in which each is combined. Grooves along the circumferential direction of the hard roll are provided at intervals of 0.6 mm to 1.8 mm in the roll width direction, Φ 畐 0.3 mm to 1.5 mm, and a depth of 0.5 mm to 2 mm. O mm.

Further, an object of the present invention is to provide a pair of press ports comprising a hard roll in which grooves along the circumferential direction are provided at predetermined intervals in the roll width direction and a soft roll having a flat roll circumferential surface. comprising a Le, the shrinkage imparted device designed to slow to rotate the peripheral speed of the soft roll against the peripheral speed of the hard roll under pressure, a basis weight of ^{5 0 g Zm 2 ~4 5 0} g in the range of Z m ^2, in a range in paper moisture of 2 0% to 50%, wet paper strength of paper direction in the moisture range of Katsuso is 0. 3 k N / m or more der The stretched paper manufacturing method is characterized in that the stretched paper is subjected to shrinkage after passing through the moisture adjusted wet paper sheet and then dried. The production method suppresses both wrinkles and shreds during shrinkage treatment.

Grooves along the circumferential direction of the hard roll are provided at intervals of 0.5 mm to 1.8 mm in the roll width direction, φ 畐 0.3 mm or more: I.5 mm, depth 0.5 mm to 2. O mm. .

The hard roll and the soft roll are under a pressure in a linear pressure range of 10 kgZcm to 70 kg / cm.

The circumferential speed of the soft roll relative to the circumferential speed of the hard roll is such that the circumferential speed of the soft roll is 0.95 to 0.5 with respect to the circumferential speed 1 of the hard roll.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram showing an example of a paper machine that implements a first example of an embodiment of a method for producing stretched paper according to the present invention,

FIG. 2 is an explanatory view of a water supply device used for carrying out the first example of the embodiment of the present invention,

FIG. 3 is a perspective view showing a shrinkage imparting device used for carrying out a first example of the embodiment of the present invention,

FIG. 4 is a vertical cross-sectional view of a hard roll used in a shrinkage imparting device used for carrying out a first example of an embodiment of the present invention,

FIG. 5 is a partially enlarged cross-sectional view showing an example of the shape of the groove of the hard roll, and FIG. 6 is an example of a paper machine that implements a second example of the embodiment of the method for producing stretched paper according to the present invention. Schematic configuration diagram showing

FIG. 7 is a perspective view showing a shrinkage imparting device used for carrying out a second example of the embodiment of the present invention,

FIG. 8 is a longitudinal sectional view of a hard roll used in a shrinkage imparting device used for carrying out a second example of the embodiment of the present invention,

FIG. 9 is a partially enlarged sectional view showing an example of the shape of the groove of the hard roll, FIG. 10 is a cross-sectional view of a soft roll used in a shrinkage imparting device used for carrying out a second example of the embodiment of the present invention,

FIG. 11 is a schematic configuration diagram showing an example of a papermaking M machine that implements a third example of the embodiment of the method for producing stretched paper according to the present invention,

FIG. 12 is a perspective view showing a shrinkage providing device used for implementing a third example of the embodiment of the present invention,

FIG. 13 is a longitudinal sectional view of a hard roll used in a shrinking device used for carrying out a third example of the embodiment of the present invention,

FIG. 14 is a partially enlarged cross-sectional view showing an example of the shape of the groove of the hard roll,

FIG. 15 is a cross-sectional view of a soft roll used in a shrinkage imparting device used for implementing a third example of the embodiment of the present invention.

FIG. 16 is a schematic configuration diagram showing an example of a paper machine that implements a fourth example of the embodiment of the method for producing stretched paper according to the present invention,

FIG. 17 is a perspective view showing a shrinkage providing device used for implementing a fourth example of the embodiment of the present invention,

FIG. 18 is a longitudinal sectional view of a hard roll used in a shrinking device used for carrying out a fourth example of the embodiment of the present invention,

FIG. 19 is a partially enlarged sectional view showing an example of the shape of the groove of the hard roll.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of a method for manufacturing a stretched paper according to the present invention will be described in detail with reference to the drawings.

First, a first example of an embodiment of a method for manufacturing a stretched paper according to the present invention will be described with reference to FIGS. 1 to 5.

In the figure, reference numeral 1 denotes basis weight is wet strength strength ^{3 5 g / m 2 ~ 4} 5 0 g / m 2 0. Lk N / n! Up to 2.0 k NZ m sheet-type paper substrate 2 A is a feeding device in which the rolled state is set, 3 is any of roll coating method, printing method, impregnation method, spray method, etc. Or each The water application device 4 is composed of a hard roll 6 having circumferential grooves 5 provided at predetermined intervals in the roll width direction on the roll circumferential surface and a soft roll 7 having a flat roll circumferential surface. A shrinkage imparting device comprising a pair of press rolls 8, wherein the peripheral speed of the soft roll Ί is made slower than the peripheral speed of the hard roll 6 under pressure to rotate, 9 is a drying device, 10 is a drying device, Is a winding device. The shrinkage imparting device 4 includes a peripheral speed adjusting means 11 for adjusting the peripheral speed of the hard roll 6 and the soft roll 7 and a pressing force adjusting means 12 for adjusting the pressurization.

In the manufacturing method using the manufacturing apparatus, the sheet-like paper base material 2A fed from the feeding apparatus 1 is made uniform in the paper layer in the paper layer by the water applying apparatus 3 so that the water content in the paper is in the range of 20% to 50%. The moisture adjusted wet paper sheet 2B is adjusted, and the moisture adjusted wet paper sheet 2B is pressed under pressure and the circumferential speed of the soft roll 7 is compared with the circumferential speed of the hard roll 6 forming the pair of press ports 8. The paper is passed through a shrinkage imparting device 4 that is rotated at a lower speed. Wet strength intensity fed to the basis weight at ^{3 5 g / m 2 ~ 4} 5 0 g Z m 2 between the hard roll 6 and the soft roll 7 is 0. .Lk NZ m~ 2. 0 k Moisture-conditioned paper sheet 2B adjusted to a water content of 20% to 50% in the range of NZ m has the effect of shearing force generated by the peripheral speed difference between hard roll 6 and soft roll 7. Then, in the longitudinal direction of the moisture-adjusting wet paper sheet 2B, the paper corresponding to the peripheral speed difference between the hard roll 6 and the soft roll 7 is compressed and longitudinal shrinkage is given, while the peripheral speed in the horizontal direction is With the compression due to the difference, the moisture-adjusting wet paper sheet 2B is pushed into the groove 5 along the circumferential direction of the hard roll 6, and contraction is given. After that, it is dried by a drying device 9 to a predetermined moisture. As a result, it was possible to easily obtain stretched paper 2C exhibiting an elongation of 20% or more in both the vertical and horizontal directions. The obtained stretched paper 2C is wound by a winding device 10 through a surface smoothing device (not shown) and a slitter (not shown) as necessary.

In more detail, the sheet-like paper substrate 2 A used in this example, in the range basis weight of ^{3 5 g / m 2 ~ 4} 5 0 g / m 2, preferably natural Pal 100% of wet paper strength in the range of 0 · lkN / m to 2.0 kNZm. It is preferable that the water content in the paper required for the shrinkage-imparting treatment can be easily adjusted, and water-resistant paper that has been subjected to a water-repellent treatment or the like is not suitable. When the wet paper strength is less than 0.1 lk NZ m, the sheet is broken when shrinking is applied by the shrinkage applying device 4 and is not practical. Also,

2. It is difficult and impractical to develop wet paper strength exceeding OkNZm.

The moisture imparting device 3 used in the embodiment of the present invention is a roll coating system, a printing system, an impregnation system, a spray system, or a combination thereof, as described above, or a combination thereof. There is no particular limitation as long as water can be sufficiently and uniformly penetrated into the 2A paper layer and the water content in the paper can be adjusted in the range of 20% to 50%. Water to be permeated may be water, hot water, or a liquid chemical such as a water-proofing agent, an oil-proofing agent, a release agent, an antibacterial agent, or the like depending on the purpose.

In this example, a water applicator 3 adopting a roll coating method shown in FIG. 2 is used, and water 14 in a pan 13 is applied to a sheet-like paper base material 2 A by a roll 15, The moisture in the paper is adjusted uniformly in the range of 20% to 50% to obtain a moisture adjusted wet paper sheet 2B.

Further, in the groove 5 along the circumferential direction of the roll peripheral surface of the hard roll 6 constituting the pair of press rolls 8 of the shrinkage imparting device 4 used in the embodiment of the present invention, the groove interval A 1, Since the groove width B1, the groove depth C1, and the groove shape affect the contact area with the moisture-adjusting wet paper sheet 2B, they are important factors from the viewpoint of enhancing the effect of applying shrinkage.

Since the moisture-adjusting wet paper sheet 2B is pushed into the groove 5 along the circumferential direction by the shearing force and contracts, the volume of the groove 5 is also an important factor. However, if the volume of the groove 5 along the circumferential direction is simply increased, the area in contact with the moisture-adjusting wet paper sheet 2B is reduced, so that sufficient frictional force cannot be obtained, and the hard roll 6 slips. It is recognized that the shear force to be pushed in is drastically reduced and the effect of imparting shrinkage is deteriorated. Scold In addition, by specifying a region that satisfies both the capacity of the groove 5 along the circumferential direction and the maintenance of the shearing force, it is possible to dramatically increase the length and width of the groove.

As described above, the moisture-adjusting wet paper sheet 2B is contracted by the shearing force of the hard roll 6 and the soft roll 7, and this shearing force is generated by the gap A1 of the groove 5 of the hard roller 6 and the groove. Depends on the contact area determined by the width B1. If the groove interval A1 of the groove 5 is narrow, the number of teeth increases, and the contact area increases. When the groove interval A1 of the groove 5 is the same, the blade width increases as the groove width B1 decreases, and the contact area increases.

In this example, among the above-mentioned elements, the grooves 5 provided along the circumferential direction provided on the hard roll 6 have a groove interval A1 of 0.6 mm to 1.8 mm in the roll width direction, and a groove width of 1 mm. B1 is formed in the range of 0.3 mm or more: I.5 mm, and groove depth C1 is formed in the range of 0.5 mm to 2.0 mm.

If the groove width B1 of the groove 5 along the circumferential direction is less than 0.3 mm or the groove depth C1 of the groove 5 along the circumferential direction is less than 0.5 mm, the moisture adjusting moisture to be shrunk is reduced. The volume of the paper sheet 2B becomes small, and a sufficient shrinkage effect cannot be obtained. If the groove width B1 of the groove 5 along the circumferential direction exceeds 1.5 mm or the groove depth C1 of the groove 5 along the circumferential direction exceeds 2.0 mm, the moisture-adjusted wet paper sheet 2 The contact area on the surface of B is reduced, and the stress during the shrinkage imparting treatment is reduced by the slip, and a sufficient shrinkage effect cannot be obtained.

The soft roll 7 of the shrinkage imparting device 4 used in the embodiment of the present invention is not particularly limited as long as it has a flat surface and is sufficiently deformed when it is closed with the hard roll. Rubber rubbers such as polyurethane rubber, chloroprene rubber, nitrile butadiene rubber, silicone rubber, polyphenol rubber, nitrile rubber, and epichloronohydrin rubber are preferred. In particular, it is important that a sufficient frictional force is obtained between the paper surface and the rubber roll in order to effectively transmit the shearing force to the paper layer, and that the surface is hardly abraded and has excellent durability. Further, in this embodiment, the hard roll 6 and the soft roll 7 are rotated under a predetermined pressure by rotating the soft roll 7 at a lower peripheral speed than the peripheral speed of the hard roll 6. Although the moisture-adjusting wet paper sheet 2B is passed through the paper so that the moisture-adjusting wet paper sheet 2B shrinks, the linear pressure of the hard roll 6 and the soft roll 7 is 10 kg Z c π! Under a pressure in the range of ~ 70 kg / cm, the hard roll 6 and the soft roll 7 are separated by a circumferential speed of the soft roll 7 of 0.95 to 0.5 with respect to a circumferential speed 1 of the hard roll 6. It is desirable to rotate in the range.

When the peripheral speed of the soft roll 7 exceeds 95% of the peripheral speed of the hard roll 6, the shearing force for shrinking the moisture adjusted wet paper sheet 2B is small, and when it is less than 50%, the moisture adjusted wet paper sheet 2 is reduced. Although the shearing force for shrinking B can be obtained sufficiently, the mechanical load increases, causing the rubber roll to break and the power load to increase, which is not preferable.

Under the pressure, when the moisture-adjusting wet paper sheet 2B is passed between the hard roll 6 and the soft roll 7, which rotate with a peripheral speed difference therebetween, the shear force obtained from the hard roll 6 and the soft roll 7 causes The moisture adjusted wet paper sheet 2B is shrunk.

Thereafter, the moisture in the moisture adjusted wet paper sheet 2B is dried to a range of 4% to 10% by the drying device 9. As a result, it was possible to easily obtain stretched paper 2C exhibiting an elongation of 20% or more in both the vertical and horizontal directions. The drying device 9 is not particularly limited as long as it can dry the water content of the shrinked moisture adjusted wet paper sheet 2B in the range of 4% to 10%. A known drying apparatus such as a drying method and a cylinder drying method can be used.

Next, a second example of the embodiment of the method for manufacturing a stretched paper according to the present invention will be described with reference to FIGS. 6 to 10.

In the paper machine according to the present embodiment, the wet paper sheet 20 A produced in the previous step is pre-dried by a drying device 21 comprising a cylinder-dryer to adjust the moisture in the paper, and the moisture-adjusted moisture is adjusted. Shrink paper sheet 20B The shrinkage-treated wet paper sheet 20C with the shrinkage given by the application device 22 is dried by the drying device 23 comprising a cylinder dryer to obtain stretched paper 20D, which is then taken up by the winder. Take up.

The shrinkage imparting device 22 includes a hard roll 25 in which circumferential grooves 24 are provided on the roll circumferential surface at predetermined intervals in the roll width direction, and a soft roll 26 having a flat roll circumferential surface. A pair of press rolls 27 each comprising: a contact length between the hard roll 25 and the soft roll 26 when pressurized is 3 Omm or more and 8 Omm or less; Peripheral speed adjusting means 28 capable of adjusting the peripheral speed of the soft roll 26 to a lower speed relative to the peripheral speed of 25, and adjusting the linear pressure between the hard roll 25 and the soft roll 26. The structure is provided with a pressure adjusting means 29 for adjustment.

The production of the stretched paper according to this example is performed as follows.

The linear pressure between the hard roll 25 and the soft roll 26 is adjusted by the pressing force adjusting means 29 of the shrinkage imparting device 22, and the peripheral speed of the hard roll 25 is adjusted by the peripheral speed adjusting means 28. After adjusting the peripheral speed of the soft roll 26 to be slow, a pair of press knurls 27 composed of the hard roll 25 and the soft roll 26 have a moisture content in the paper of 20% or more. Pass the moisture-adjusted wet paper sheet 20B, which is preliminarily dried and adjusted to 50% by the drying device 21.

Here, the moisture-adjusting wet paper web sheet 20 B passed between the hard roll 25 and the soft roll 26 has a shear force generated by the difference in peripheral speed between the hard roll 25 and the soft roll 26. Be affected. As a result, in the longitudinal direction of the moisture-adjusting wet paper sheet 20B, a paper layer corresponding to the peripheral speed difference between the hard mouth 25 and the soft roll 26 is compressed to impart longitudinal shrinkage. On the other hand, in the transverse direction, the paper layer is pushed into the grooves 24 along the circumferential direction of the hard roll 25 due to the compression due to the difference in the peripheral speed, so that the lateral contraction is given. Thereafter, the shrinkage-treated wet paper sheet 20 C to which the shrinkage has been imparted is dried to a predetermined moisture by the drying device 23. Thus, a basis weight of ^{5 0 g / m 2 ~ 4} 5 0 Stretched paper 20D exhibiting an elongation of 20% or more in g / m ² in both length and width was easily obtained.

More specifically, it is composed of a hard roll 25 and a soft roll 26, and the peripheral speed of the soft roll 26 is made slower than the peripheral speed of the hard roll 25, and a pair of press jars 2 to which pressure is applied is used. Pass the moisture-adjusted wet paper sheet 20B adjusted so that the moisture content in the paper is 20% to 50% through 7.

In order to easily produce stretched paper 20D having high stretching properties, the moisture in the moisture-adjusting wet paper sheet 20B during processing affects the plasticity of the moisture-adjusting wet paper sheet 20B as described above. This is an important factor, and in this example, the water content of the moisture-adjusting wet paper sheet 20B is adjusted to be 20% to 50%.

Further, the pressure of the hard roll 25 and the soft roll 26 of the shrinkage imparting device 22, the contact length of the hard roll 25 and the soft mouth 26 when pressurized, the hard roll 25 and the soft mouth The peripheral speed difference of the roller 26 and the shape of the groove 24 provided in the hard roll 25 are determined by the moisture-adjusting wet paper sheet 20 B due to the shearing force generated between the hard roll 25 and the soft roll 26. This is an important factor in providing shrinkage.

The pressure of the hard roll 25 and the soft roll 26 is preferably under a linear pressure of 10 kg / cm to 70 kg / cm. Under this pressure, it is possible to obtain a frictional force between the moisture-regulating wet paper sheet 20B and the soft roll 26 that generates a shearing force sufficient to impart shrinkage to the moisture-regulating wet paper sheet 20B. it can.

The contact length between the hard roll 25 and the soft roll 26 under pressure is the most important for efficiently transmitting the shearing force to the paper layer of the moisture-adjusting wet paper sheet 20B. In the present invention, the contact length is set to 30 mm or more and 80 mm or less, preferably 30 mm or more and 60 mm or less. By setting the contact length to 3 O mm or more and 80 mm or less, the moisture adjustment wet paper web 20B and the soft roll 26 The frictional force that generates a sufficient shearing force to impart shrinkage to the paper sheet 20B is obtained, and the wear on the surface of the soft roll 26 is suppressed without applying unnecessary frictional force. If the contact length is less than 30 mm, sufficient frictional force cannot be obtained, causing slippage between the moisture-adjusting wet paper sheet 20B and the soft roll 26, and the shear force is drastically reduced, resulting in an effect of imparting shrinkage. However, if the contact length exceeds 80 mm, a sufficient shearing force can be obtained, but the mechanical load becomes large, and the surface of the soft rubber roll 7 becomes harder. As the wear increases, the power load increases, which is uneconomical.

In addition, regarding the peripheral speed difference between the hard roll 25 and the soft roll 26, the shear force generated by the peripheral speed difference between the hard roll 25 and the soft roll 26 is efficiently used for the moisture-adjusting wet paper sheet 20. It is important to act on the layer B, and the hard roll 25 and the soft roll 26 are placed under a linear pressure of 10 kg / cm to 70 kg / cm, and the hard roll 25 It is preferable to rotate the soft roll 26 and the soft roll 26 in a range of 0.95 to 0.5 with respect to the circumferential speed 1 of the hard roll 25. When the circumferential speed of the soft roll 26 is 95% or more of the circumferential speed of the hard roll 25, the shear force for shrinking the moisture-adjusting wet paper sheet 20B is small. Although a sufficient shearing force to shrink 20B can be obtained, the mechanical load increases, leading to abrasion and breakage of the surface of the soft roll 26 and a large power load, which is not preferable.

When the moisture-adjusted wet paper sheet 20B is passed between the hard roll 25 and the soft roll 26 rotating at a peripheral speed difference between the two under the pressure, the hard roll 25 and the soft roll 2 The moisture adjusted wet paper sheet 20 B is shrunk by the shearing force obtained from 6.

Further, regarding the shape of the groove 24 provided on the hard roll 25, the groove interval A2, the groove width B2, the groove depth C2, and the groove shape are the moisture-adjusting wet paper sheet 20B. This is an important factor in terms of enhancing the shrinkage effect because it affects the contact area with the surface. Moisture adjusted wet paper sheet 20 B is shearing force Is pressed into the groove 24 along the circumferential direction and contracts, so that its volume is the most important factor. However, simply increasing the volume of the groove 24 along the circumferential direction reduces the area in contact with the moisture-adjusting wet paper sheet 20B, so that sufficient frictional force cannot be obtained, and the hard roll 25 slips. It is recognized that the shear force to be pushed in is drastically reduced and the effect of imparting shrinkage is inferior. However, by specifying a region that satisfies both the volume of the groove 24 along the circumferential direction and the maintenance of the shearing force, the longitudinal and lateral elongation can be significantly increased.

As described above, the moisture-adjusting wet paper sheet 20 B contracts due to the shearing force of the hard roll 25 and the soft mouth 26, and this shearing force is generated by the grooves 24 of the hard roll 25. Depends on the contact area determined by groove spacing A2 and groove width B2. If the groove interval A2 is small, the number of teeth increases and the contact area increases. Further, when the groove interval A2 is the same, the blade width increases as the groove width B2 decreases, and the contact area increases.

In the present example, among the above-mentioned elements, the groove 24 along the circumferential direction provided on the hard roll 25 has a groove interval 2 in the roll width direction of 0.6 mm to The groove width B2 is 0.3 mm to 1.5 mm, and the groove depth C2 is 0.5 mm to 2.0 mm.

If the groove width B2 of the groove 24 along the circumferential direction is less than 0.3 mm or the groove depth C2 of the groove 24 along the circumferential direction is less than 0.5 mm, the water content to be shrunk is adjusted. The volume of the wet paper sheet 20B is reduced, and a sufficient shrinking effect cannot be obtained. If the groove width B 2 of the groove 24 along the circumferential direction exceeds 1.5 mm or the groove depth C 2 of the groove 2 along the circumferential direction exceeds 2.0 mm, the moisture-adjusting wet paper sheet 2 0 The contact area of the surface of B becomes small, and the stress at the time of the shrinkage imparting treatment is reduced by the slip, so that a sufficient shrinkage effect cannot be obtained. The shape of the groove 24 is also important, and various shapes can be considered, but a V shape, a U shape, and a concave shape are particularly preferable. The material of the hard roll 25 is stainless steel, iron, aluminum, copper, brass, Ceramics and the like can be used.

The soft roll 26 having a flat roll peripheral surface used in the shrinkage imparting device 22 of the present example is not particularly limited as long as the surface is flat, but it is not limited to polyurethane rubber, chloroprene rubber, or the like. Rubber rolls such as tolylbutadiene rubber, silicone rubber, policer / refide rubber, nitrile rubber, and epichlorohydrin rubber can be suitably used. In particular, it is important that a sufficient frictional force between the paper surface and the soft roll 26 is obtained, the surface is hardly abraded, and the durability is excellent in order to effectively transmit the shear force to the paper layer. As shown in FIG. 10, the soft roll 26 is composed of a metal core roll 26 a and a soft material surface layer 26 b, and the surface layer 26 b has a thickness of the soft roll 26. The one formed in the range of 5 to 40% with respect to the diameter of 100 can be suitably used. If the thickness of the surface layer portion 26b is less than 5%, the amount of the soft material is small, and the conditions for obtaining the contact width cannot be adjusted due to the influence of the metal core roll 26a. On the other hand, when the temperature exceeds 40 ° / ₀ , the amount of the soft material is large and the metal core roll 26a is not affected, but the surface is liable to be abraded, which is not practical.

In the wet paper sheet 20A, the raw pulp used is preferably natural pulp. As natural pulp, ordinary papermaking raw materials such as coniferous or hardwood wood fibers, bast fibers such as mitsumata and kozo, non-wood fibers such as bagasse and kenaf, cotton fibers, and used paper can be used. Softwood or hardwood wood fibers are preferred.

A general paper machine such as an ordinary fourdrind multi-cylinder or a round net multi-cylinder can be used as the paper machine for carrying out the present embodiment. It is desirable that it can be installed during the process, and the moisture content of the moisture-adjusting wet paper sheet 20B is 20% to 50%. /. There is no particular limitation as long as it can be installed between the drying device 21 capable of preliminary drying in the range of and the drying device 23 capable of drying the paper to a moisture of about 3 to 10%. Next, a third example of an embodiment of the method for manufacturing a stretched paper according to the present invention will be described with reference to FIGS. 11 to 15.

In the paper machine according to the present embodiment, the wet paper sheet 3 OA produced in the previous step is pre-dried by a drying device 31 comprising a cylinder dryer to adjust the moisture in the paper, 30 B is given the required shrinkage by the shrinkage applying device 32, and the shrinkage-treated wet paper sheet 30C with the shrinkage is dried by the drying device 33 comprising a cylinder drier to obtain the expanded paper 30D. Take it up with a winder.

The shrinkage imparting device 32 includes a hard roll 35 in which circumferential grooves 34 are provided at predetermined intervals in the roll width direction on a roll circumferential surface, and a soft roll 36 having a flat roll circumferential surface. A pair of press rolls 37 comprising: a peripheral speed adjusting means 38 capable of adjusting the peripheral speed of the soft roll 36 to be lower than the peripheral speed of the hard roll 35 under pressure. And a pressure adjusting means 39 for adjusting the linear pressure between the hard roll 35 and the soft roll 36. The soft roll 36 forming a pair of press rolls 37 together with the hard roll 35 is provided on the outer periphery of the metal core roll 36 a with a surface layer portion 36 made of a material having excellent wear resistance. It has a two-layer structure in which b and an inner layer part 36 c made of a material that is easily deformed under pressure are integrated.

The linear pressure between the hard roll 35 and the soft roll 36 is adjusted by the pressurizing force adjusting means 39 of the shrinkage imparting device 32, and the peripheral speed adjusting means 38 adjusts the linear speed of the hard roll 35. After adjusting the peripheral speed of the soft roll 36 to be slow, the pair of press ports 37 composed of the hard roll 35 and the soft roll 36 have a water content of 20% Pass through a moisture-regulated wet paper sheet 30 B whose moisture has been adjusted by pre-drying with a drying device 31 so as to be 50%.

Here, the moisture-adjusting wet paper sheet 30 B passed between the hard roll 35 and the soft roll 36 is formed around the circumference of the hard roll 35 and the soft mouth 36. It is affected by the shear force generated by the speed difference. As a result, in the longitudinal direction of the moisture-adjusted wet paper sheet 30B, a paper layer corresponding to the peripheral speed difference between the hard roll 35 and the soft roll 36 is compressed, and longitudinal shrinkage is imparted. On the other hand, in the transverse direction, the paper layer is pushed into the grooves 34 along the circumferential direction of the hard roll 35 due to the compression due to the difference in the peripheral speed, so that the lateral contraction is given. Thereafter, the shrink-treated wet paper sheet 30 C to which shrinkage has been imparted is dried to a predetermined moisture by the drying device 33. Thus, a basis weight of 5 0 g was Z m ² ~ 4 5 0 g in _ m ² vertically and horizontally can be obtained easily stretched sheet 3 0 D showing a 2 0% or more Shinpi.

More specifically, it is composed of a hard roll 35 and a soft roll 36, and the peripheral speed of the soft mouth 36 is made slower than the peripheral speed of the hard roll 35, and a pair of press ports which are pressurized. The moisture adjusted wet paper sheet 30B adjusted so that the moisture in the paper becomes 20% to 50% is passed through the paper 37.

In order to easily produce stretched paper 30D having high stretching properties, the moisture in the moisture-adjusting wet paper sheet 30B during processing affects the plasticity of the moisture-adjusting wet paper sheet 30B as described above. This is an important factor, and in this example, the water content of the moisture-adjusting wet paper sheet 30B is adjusted so that the water content in the paper is 20% to 50%.

In addition, the soft roll 36 that imparts shrinkage to the moisture-adjusting wet paper sheet 30B together with the hard roll 35 of the shrinkage imparting device has excellent wear resistance on the outer periphery of the metal core roll 36a. It has a two-layer structure in which a surface layer part 36 b made of a material and an inner layer part 36 c made of a material that is easily deformed under pressure are integrated. By doing so, a sufficient shearing force is generated between the moisture control wet paper sheet 30B and the soft roll 36 to apply shrinkage to the moisture control wet paper sheet 30B. The frictional force to be obtained is obtained, and the frictional force is not applied more than necessary, so that the wear on the surface of the soft roll 36 is suppressed and the durability is improved.

The surface layer 36 b of the soft roll 36 has abrasion resistance of 0. It is preferable to be made of a material of O 5 cc Zl O 0 O or less, and of a material whose inner layer portion 36 c has a compression deformation of 4% or more when compressed at a pressure of SO. In this example, the abrasion resistance was measured using a wear tester under the following conditions: preliminary wear 3 000 times, main test 100 0 times, load 27.0 N, wheel angle 15 °. Is used to measure the wear reduction capacity. The amount of compression change is the amount of deformation when a 60 mm X 50 mm X 11 O mm thick rubber specimen is compressed at a compression speed of 10 mm / min with a stress of 1.5 kN. It is to be measured. At this time, since the under pressure of 1. 5 k N on specimens of the area 3 0 0 O mm ^2, it means that compress the test piece at a pressure of 0. 5MP a.

Further, it is preferable that the ratio of the thickness of the surface layer portion 36 b to the inner layer portion 36 c of the soft roll 36 is surface layer portion: inner layer portion 5/95: 30/70. If the ratio of the surface layer portion 36 b is less than 5, the surface strength becomes insufficient, and if it exceeds 30, the effect of imparting shrinkage becomes insufficient.

The material of the surface layer portion 36 b and / or the inner layer portion 36 c of the soft roll 36 may be polyurethane rubber, chloroprene rubber, nitrile butadiene rubber, silicone rubber, polysulfide rubber, or nitrile rubber. And epichlorohydrin rubber can be used.

In addition, the pressure of the hard roll 35 and the soft roll 36 of the shrinkage imparting device 32, the contact length of the hard roll 35 and the soft roll 36 during pressurization, and the pressure of the hard roll 35 and the soft roll 36 The peripheral speed difference and the shape of the groove 34 provided in the hard roll 35 caused the shrinkage of the moisture adjusting wet paper sheet 30 B due to the shearing force generated between the hard roll 35 and the soft roll 36. This is an important factor to be granted.

The pressure of the hard roll 35 and the soft roll 36 is preferably under a linear pressure of 10 kg / cm to 70 kg / cm. Under this pressure, it is possible to obtain a frictional force between the moisture-adjusting wet paper sheet 30B and the soft roll 36 that generates a shearing force sufficient to impart shrinkage to the moisture-adjusting wet paper sheet 30B. it can. In addition, in the peripheral speed difference between the hard roll 35 and the soft roll 36, the shear force generated by the peripheral speed difference between the hard roll 35 and the soft roll 36 is efficiently used for the moisture control wet paper sheet 30. It is important to act on the layer B, and the hard roll 35 and the soft roll 36 are placed under a linear pressure of 10 kg / cm to 70 kg Zcm, and the hard roll 35 It is desirable to rotate the soft roll 36 and the soft roll 36 in a range of 0.95 to 0.5 with respect to the circumferential speed 1 of the hard roll 35. When the circumferential speed of the soft roll 36 exceeds 95% of the circumferential speed of the hard roll 35, the shearing force for shrinking the moisture-adjusting wet paper sheet 30B is small. Although a sufficient shearing force to shrink the sheet 30B can be obtained, the mechanical load is increased, and the surface of the soft roll 36 is worn or damaged, and the power load is increased.

When the moisture-adjusted wet paper sheet 30B is passed between the hard roll 35 and the soft roll 36 rotating with a peripheral speed difference between the two under the pressure, the hard roll 35 and the soft roll ³ The moisture adjusted wet paper sheet 30 B is shrunk by the shearing force obtained from 6.

Further, in the hard roll ₃₅ in the groove 3 4 shape or the like provided, the groove spacing A 3, the groove width B 3, the groove depth C 3, the groove shape, moisture control wet paper sheet 3 0 B This is an important factor in terms of enhancing the shrinkage effect because it affects the contact area with the surface. The volume is the most important factor because the moisture-adjusting wet paper sheet 30 B is pushed into the circumferential groove 34 by the shearing force and contracts. However, simply increasing the volume of the groove 34 along the circumferential direction reduces the area in contact with the moisture-adjusting wet paper sheet 30B, so that sufficient frictional force cannot be obtained, and the hard roll 35 slips. It can be seen that the shearing force caused by waking up and pushing down sharply decreased, and the effect of imparting shrinkage deteriorated. However, by specifying an area that satisfies both the volume of the groove 34 along the circumferential direction and the maintenance of the shearing force, it is possible to significantly increase the vertical and horizontal extension.

As described above, the moisture-adjusted wet paper sheet 30 B is made of a hard roll 35 and soft. It contracts due to the shearing force of the mouth 36, and this shearing force depends on the contact area determined by the groove spacing A 3 and the groove width B 3 of the grooves 34 of the hard roll 35. If the groove interval A3 is small, the number of teeth increases, and the contact area increases. Further, when the groove interval A3 is the same, the blade width increases as the groove width B3 decreases, and the contact area increases.

In the present example, among the respective elements, the groove 34 along the circumferential direction provided on the hard roll 35 has a groove interval A3 of 0.6 mm in the roll width direction, as in the first example. The groove width B3 is formed in the range of 0.3 mm to 1.5 mm, and the groove depth C3 is formed in the range of 0.5 mm to 2.0 mm at intervals of ~ 1.8 mm.

If the groove width B3 of the groove 34 along the circumferential direction is less than 0.3 mm or the groove depth C3 of the groove 34 along the circumferential direction is less than 0.5 mm, the water content to be shrunk is adjusted. The volume of the wet paper sheet 30B becomes small, and a sufficient shrinkage effect cannot be obtained. If the groove width B3 of the groove 34 along the circumferential direction exceeds 1.5 mm or the groove depth C3 of the groove 34 along the circumferential direction exceeds 2.0 mm, the moisture-adjusting wet paper The contact area of the surface of the sheet 30B is reduced, and the stress in the shrinkage imparting treatment 2 is reduced by the slip, and a sufficient shrinkage effect cannot be obtained. The shape of the groove 34 is also important, and various shapes are conceivable, but a V-shape, a U-shape, and a concave shape are particularly preferable. The material of the hard roll 35 can be stainless steel, iron, aluminum, copper, brass, ceramics, or the like.

Further, in the wet paper sheet 30A, the raw pulp used is preferably natural pulp. As natural pulp, ordinary papermaking raw materials such as coniferous or hardwood wood fibers, bast fibers such as mitsumata and kozo, non-wood fibers such as bagasse and kenaf, cotton fibers, and used paper can be used. Softwood or hardwood wood fibers are preferred.

Although a general paper machine such as an ordinary fourdrind multi-cylinder or a round net multi-cylinder can be used as the paper machine for implementing this example, the shrinkage imparting device used in the practice of this example 3 2 It is desirable that a shrinkage-imparting equipment can be installed during the papermaking process, and a drying device 31 that can pre-dry the moisture content of the wet paper sheet 30A in the range of 20% to 50% and a normal paper There is no particular limitation as long as it can be installed between the drying devices 33 capable of drying the water to about 3 to 10%.

Next, a fourth example of an embodiment of the method for producing a stretched paper according to the present invention will be described with reference to FIGS. 16 to 19.

Even in the paper machine according to the present embodiment, the wet paper sheet 40A produced in the previous step was pre-dried by a drying device 41 comprising a cylinder dryer to adjust the water content in the paper. The adjusted wet paper sheet 40 B is given the required shrinkage by the shrinkage imparting device 42, and the shrinkage treated wet paper sheet 40 C that has been shrunk is dried by the drying device 43 consisting of a cylinder drier 43. Obtain 0 D and wind it with a winder.

The shrinkage imparting device 42 includes a hard roll 45 provided with grooves 44 along a circumferential direction on the roll circumferential surface at predetermined intervals in a mouth width direction, and a soft roll 46 having a flat roll circumferential surface. A pair of press rolls 47 comprising: a peripheral speed adjusting means 4 capable of adjusting the peripheral speed of the soft roll 46 to be lower than the peripheral speed of the hard roll 45 under pressure so as to rotate. 8 and a pressure adjusting means 49 for adjusting the linear pressure between the hard roll 45 and the soft roll 46.

The moisture adjusted wet paper sheet 40 B whose moisture in the paper has been adjusted by the drying device 41 is passed through the shrinkage imparting device 42, and the linear pressure between the hard roll 45 and the soft roll 46 is applied by the pressing force adjusting means 49. Further, the peripheral speed adjusting means 48 adjusts the peripheral speed of the soft roll 46 to be lower than the peripheral speed of the hard roll 45, thereby giving a contraction to the moisture adjusted wet paper sheet 40B. I can. At this time, an appropriate tension is applied between the mouth 50 and the pair of press rolls 47 composed of the hard roll 45 and the soft Lorenole 46 so that wrinkles do not occur. The moisture adjusted wet paper sheet 40B used in this example has a basis weight of 50 g Zm ² to 450 g / m ² and a paper moisture content of 20% to 50%. In addition, the strength of the wet paper web in the papermaking direction within the moisture range is 0.

It must be at least 3 kN / m. The material of the moisture-adjusting wet paper sheet 40B is not particularly limited. However, due to the problem of waste treatment and environmental load due to global environmental problems, paper having a composition of 100% natural pulp is used. It is preferable that As the natural pulp, ordinary papermaking materials such as coniferous or hardwood wood fibers, bast fibers such as mitsumata and kozo, non-wood fibers such as bagasse and kenaf, cotton fibers, and used paper can be used. Alternatively, hardwood wood fibers are preferred.

Here, the wet paper strength in the paper making direction in this example is defined as follows.

First, the wet paper sheet adjusted so that the moisture content in the paper is in the range of 20% to 50% is cut into a strip shape with a width of 15 mm and a length of 150 mm so that the papermaking direction is the long side direction. I do. Then, using a universal tensile tester according to JISP 8113, this strip-shaped wet paper sheet is gripped at the upper and lower sides with a distance of 100 mm at the grip part, and immediately The strength until breaking at a stretching speed of 500 mmZ was measured, and the obtained strength was defined as wet paper web strength.

In this example, the reason why the wet paper strength of the moisture-adjusting wet paper sheet 40 B is 0.3 kNZm or more is that when the wet paper strength is less than 0.3 kN / m, the shrinkage applying device is used.

When shrinking the moisture-adjusting wet paper sheet 40 B in 42, wrinkles are generated if sufficient tension is not applied between the press rolls 47 and 50 to prevent wrinkles. If the necessary tension is applied to the paper, paper breakage may occur. If the wet-adjustable wet paper sheet 40B is given an unnecessarily strong wet paper strength and a high tension is applied to the wet-adjustable wet paper sheet 40B, the moisture-adjustable wet paper sheet 40B will be stretched before the shrinkage treatment, although the wrinkle prevention effect is excellent. Unnecessarily high tension because the processing effect of the shrinkage applying device 42 is reduced. The wet paper strength is preferably less than 5.O kN / m so that no force is applied. The wet paper strength of the moisture-adjusting wet paper sheet 40 B is sufficient if it has a wet paper strength that can withstand the tension that can exhibit the wrinkle prevention effect, and a wet paper strength exceeding 5.0 kNZm. Is unnecessary.

The reason why the moisture content of the moisture-adjusting wet paper sheet 4 OB is set to the range of 20% to 50% is that when the moisture content in the paper is less than 20%, it acts as a plasticizer for the moisture-adjusting wet paper sheet 40B. This is because the water content is low and the rigidity is high, so that the energy for imparting shrinkage increases, and sufficient shrinkage cannot be imparted. If the moisture content in the paper exceeds 50%, the plasticity of the moisture-regulated wet paper sheet 40B can be maintained, but the water squeezed out by pressurization tends to cause a slip during treatment, which is sufficient. This is because shrinkage cannot be applied.

To adjust the wet paper strength in the range of 20% to 50% in paper and the wet paper strength in the moisture range to 0.3 kN / m to 5 kNZm, adjust the degree of beating of the raw pulp. Alternatively, paper strength enhancers such as aldehyde starch, polyethyleneimine, polyacrylamide resin, urea-formaldehyde resin, melamine'formaldehyde resin, polyamide-polyamine epichlorohydrin resin are effective. is there. When the moisture-adjusting wet paper sheet 40B obtained as described above is passed between the hard roll 45 and the soft roll 46 while applying an appropriate tension, the moisture-adjusting wet paper sheet 4 0 B is hard roll 4 5 and soft roll 4

It is affected by the shear force generated by the peripheral speed difference of 6. Accordingly, the longitudinal direction of the moisture-adjusting wet paper sheet 40B is divided into a hard roll 4 5 and a soft roll 4

The paper layer corresponding to the peripheral speed difference of 6 is compressed to apply longitudinal shrinkage. On the other hand, in the transverse direction, the paper layer is pushed into the groove 44 along the circumferential direction of the hard roll 45 due to the compression due to the difference in the peripheral speed, so that the lateral contraction is given. More specifically, it is composed of a hard roll 45 and a soft roll 46. The peripheral speed of the soft roll 46 is made slower than the peripheral speed of the hard roll 45, and a pair of press rolls 47 are applied with pressure. , Paper moisture and wet paper strength The moisture-adjusted wet paper sheet 40B adjusted in the above is passed through. The paper layer of the moisture-adjusting wet paper sheet 40 B interposed between the hard roll 45 and the soft roll 46 receives the action of the shear force generated by the peripheral speed difference between the hard roll 45 and the soft roll 46. Thus, the moisture-adjusting wet paper sheet 40B is contracted in the vertical and horizontal directions as described above.

Therefore, it is important to apply the shrinkage to the moisture-adjusting wet paper sheet 40 B by efficiently applying the shearing force generated by the peripheral speed difference between the hard roll 45 and the soft roll 46 to the paper layer. In order to apply an appropriate shearing force to the paper layer, it is necessary to maintain the frictional force at each interface of the hard roll 45 Z moisture-regulating wet paper sheet 40 B / soft roll 46. In order to maintain the frictional force and enhance the shrinkage effect, the groove spacing A4, groove width B4, groove depth C4, and groove shape along the circumferential direction of the hard roll 45 adjust the moisture content. This is an important factor for affecting the contact area with the wet paper sheet 40B. On the other hand, the soft roll 46 is also an important factor because the moisture adjustment wet paper sheet 40B is deformed by the deformation caused by the pressure / peripheral speed difference. Therefore, the combination of the hard roll 45 and the soft roll 46 is an important factor, and the peripheral speed difference between the hard roll 45 and the soft roll 46 is also an important factor because it affects the absolute amount of shearing force. is there.

The combination of the above-described elements makes it possible to more easily and more reliably impart high elongation characteristics simultaneously in both the vertical and horizontal directions, which has been conventionally difficult. In particular, the interval, depth and width of the grooves 44 along the circumferential direction of the hard roll 45 are such that the moisture-adjusting wet paper sheet 40B is pushed into the grooves 44 along the circumferential direction by shearing force and contracts. Therefore, its volume is also an important factor. However, simply increasing the volume of the groove 44 along the circumferential direction reduces the area in contact with the moisture-adjusting wet paper sheet 40B, so that sufficient frictional force cannot be obtained and the hard roll 45 slips. It is recognized that the shearing force to be pushed in drastically decreased and the effect of imparting shrinkage became inferior. However, by specifying a region that can satisfy both the volume of the groove 4 along the circumferential direction and the maintenance of the shearing force, the vertical and horizontal expansion can be reduced. It can be provided dramatically.

Among the above-mentioned elements, the grooves 44 provided along the circumferential direction provided on the hard roll 45 have, in the present example, a groove interval A4 of 0.5 mm to 1.8 mm in the roll width direction, Groove width B 4 is 0.3 mm to 1.5 mm, groove depth 〇 4 is 0.5 mn! It is formed in the range of ~ 2.0 mm. If the groove width B4 of the groove 44 along the circumferential direction is less than 0.3 mm or the groove depth C4 of the groove 44 along the circumferential direction is less than 0.5 mm, shrinkage occurs. The volume of the moisture-adjusting wet paper sheet 40 B to be formed becomes small, and a + minute shrinkage effect cannot be obtained. If the groove width B 4 of the groove 44 along the circumferential direction exceeds 1.5 mm or the groove depth C 4 of the groove 44 along the circumferential direction exceeds 2.0 mm, the ice content The contact area of the surface of the paper sheet 40B is reduced, and the stress during the shrinkage treatment is reduced by the slip, so that a sufficient shrinkage effect cannot be obtained.

Soft quality roll 4 6 constituting the press roll ⁴ 7 forms the hard roll 4 5 and pair flat roll circumferential surface, the hard roll 4 5 a - long as it sufficiently deformed when-up Although it is not particularly limited, rubber rolls made of polyurethane rubber, chloroprene rubber, nitrile butadiene rubber, silicone rubber, policer / refide rubber, nitrile rubber, epichlorohydrin rubber and the like are preferable. In particular, in order to effectively transmit the shearing force to the moisture-adjusting wet paper sheet 40 B, the frictional force between the surface of the moisture-adjusting wet paper sheet 40 B and the soft roll 46 can be obtained in + minutes and the surface wear can be reduced. It is important that they are difficult to perform and have excellent durability.

It is important that the hard roll 45 and the soft roll 46 efficiently apply a shear force generated by a peripheral speed difference between them under a predetermined pressure to the layer of the moisture-adjusting wet paper sheet 40B. The hard roll 45 and the soft mouth 46 are placed under a linear pressure of 10 kg gcm to 70 kg gcm, and the hard mouth 45 and the soft mouth 46. It is preferable that the peripheral speed of the soft roll 46 be rotated in the range of 0.95 to 0.5 with respect to the peripheral speed 1 of the hard opening 45. When the peripheral speed of the soft roll 46 exceeds 95% of the peripheral speed of the hard roll 45, the shear force for shrinking the moisture-adjusting wet paper sheet 40B is small, and sufficient elongation is provided simultaneously in the longitudinal and lateral directions. I can't do it. If the circumferential speed of the soft roll 46 is less than 50% of the circumferential speed of the hard roll 45, a sufficient shearing force can be obtained, but the mechanical load increases and the rubber roll breaks and power It is not preferable because it causes a large load. When the moisture-adjusting wet paper sheet 40B is passed between the hard roll 45 and the soft roll 46 rotating at a peripheral speed difference between the two under the pressure, the hard roll 45 and the soft roll 4 The moisture adjusted wet paper sheet 40 B is shrunk by the shearing force obtained from 6.

Thereafter, the moisture in the paper of the shrink-treated wet paper sheet 40C obtained by shrink-treating the moisture-adjusted wet paper sheet 40B in the drying device 43 is dried to a range of 4% to 10%. As a result, it was possible to easily obtain stretched paper 40D exhibiting an elongation of 20% or more in both the vertical and horizontal directions. The drying device 43 is not particularly limited as long as it can dry the water content of the shrinked moisture-adjusting wet paper sheet 40B to a range of 4% to 10%. Known drying devices such as a hot air drying system and a multi-cylinder cylinder-drying system used in a normal paper machine can be used.

As the paper machine for carrying out this example, a general paper machine such as an ordinary fourdrind multi-cylinder or a round net multi-cylinder can be used, but the hard roll 45 for shrinking the moisture-adjusting wet paper sheet 40B and the soft roll are used. A pair of press rolls consisting of rolls 4 and 6

It is desirable that the shrinkage imparting device 42 equipped with 47 can be installed during the papermaking process.

Adjusted to the range of 50% .Especially limited as long as it can be installed between the drying device 41 that can perform preliminary drying and the drying device 43 that can dry normal paper moisture to about 3 to 10%. Not something.

Next, the present invention will be described in further detail by examples. First, a first example of the above embodiment will be described based on Examples 1 and 2 and Comparative Example 1. In each of the examples and comparative examples, A roll coating method was used in which a roll 15 in which a cloth was wound was immersed in a pan 13 in which the roll 14 was stored, and the water 14 absorbed by the roll 15 was transferred to the sheet-like paper substrate 2A. In addition, the shrinkage imparting device 4 has a groove interval A1 of 1.2 mm, a groove width B1 of 0.8 mm, a groove depth C1 force S of 1.2 mm, and has a V-shaped hole circumferentially. A hard roll 6 made of stainless steel and a soft roll 7 made of flat nitrile-butadiene rubber having grooves 5 along the roll width direction were used. The drying device 9 was a hot-air drying device, and was dried under a temperature condition in which the water content after drying was 10%.

(Example 1)

And a sheet-like paper substrate 2 A, the basis weight 7 8 g / m ² wet strength strength using unbleached kraft paper 0. 6 2 k N / m, the the paper in moisture supply device 3 water It was adjusted to 28% to prepare a moisture-adjusted wet paper sheet 2B. The moisture-adjusting wet paper sheet 2B is introduced into a shrinkage imparting device 4 to which a linear pressure of 35 kg Z cm is applied, shrinked and dried to obtain a stretched paper 2C, which is wound by a winding device 10 I wiped it. After the line speed became stable, the peripheral speed of the soft roll 7 was gradually reduced in the shrinkage imparting device 4, and finally, the soft roll 7 was rotated at a speed of 85% of the peripheral speed of the hard roll 6. . At this time, the payout speed was equal to the peripheral speed of the hard roll 6, and the winding speed after drying was almost equal to the peripheral speed of the soft roll 7. Table 1 shows the physical properties of the obtained expanded paper 2C.

(Example 2)

The resulting stretch sheet 2 C except that wet strength strength with processing base paper 0. 9 8 k NZm as a sheet-like paper substrate 2 A basis weight 1 1 7 gZm ² in the same manner as in Example 1 Was. Table 1 shows the physical properties of the obtained stretched paper 2C.

(Comparative Example 1)

Except for using a high-quality paper with a basis weight of 1 2 3 g Zm ² and a wet paper strength of 0.08 kNZm as the sheet-like paper base material 2 A, the same procedure was performed as in Example 1, but the paper was cut. There has occurred. Table 1 shows the physical properties of the obtained stretched paper 2C. [table 1 ]

Next, a second example of the above embodiment will be described based on Examples 3 to 8 and Comparative Examples 2 to 7. In each of Examples and Comparative Examples, papermaking was performed under the following common conditions except for the configuration of the shrinkage imparting device 22. As the papermaking raw material, general-purpose N-BKP pulp beaten to a freeness of 300 m 1 was used to make the paper with a set basis weight of 150 g Zm ² on the wire. The paper machine is an ordinary multi-cylinder Fourdrinier paper machine and a schematic diagram is shown in Fig. 6. The shrinkage imparting device 22 was installed at the approximate middle position of the drying devices 21 and 23 equipped with more than ten cylinder dryers. The drying device 21 at the previous stage of the shrinkage imparting device 2 2 adjusts the moisture content of the wet paper sheet 20A produced in the previous process to 40%, and the moisture-adjusted moisture adjusted wet paper sheet 20B is subjected to the shrinkage imparting device 2 The shrinkage-treated wet paper sheet 20 C subjected to shrinkage in 2 and dried was dried in a drying device 23 so that the water content became 6% to obtain stretched paper 20 D.

(Example 3)

In the shrinkage imparting device 22, the groove 24 having a groove interval A2 of 1.2 mm, a groove width B2 of 0.8 mm, and a groove depth C2 of 1.2 mm extends in the roll width direction. a hard roll ² 5 of diameter 2 5 O mm consisting provided stainless, front surface layer portion 2 6 b of the two preparative drill butadiene rubber on the surface of the metal core roll 2 6 a is coated to a thickness of 1 5 mm roll peripheral surface of which the diameter 2 5 0 mm is provided with a pressing outlet Ichiru ² 7 consisting of flat soft roll 2 6. The hard roll 25 constituting the press roll 27 and the soft roll 25 When the moisture-adjusted wet paper sheet 20B was passed between the nipples 26 and a linear pressure of 75 kg / cm was applied, the contact length was 32 mm. The soft roll 26 was rotated at a speed of 85% of the peripheral speed of the hard roll 25 and contracted. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6%, and stretched paper 20D was obtained. The obtained stretched paper 20D had no wrinkles and good elongation. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Example 4)

As a soft roll 26 with a flat peripheral surface that forms the press roller 27, a polyurethane rubber surface layer 26b is formed on the surface of the metal core roll 26a to a thickness of 15 mm. The same shrinkage imparting device 22 as in Example 3 was used except that a soft roll 26 having a diameter of 25 O mm and a flat roll peripheral surface was used. When a moisture-adjusted wet paper sheet 20 B was passed between a hard roll 25 and a soft roll 26 constituting the press mouth 27 and a linear pressure of 62 kg / cm was applied, a contact length was obtained. The height was 46 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6% to obtain stretched paper 20D. The obtained stretched paper 20D had no wrinkles and good elongation. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Example 5)

As a soft roll 26 having a flat roll peripheral surface constituting the press roll 27, a surface layer portion 26b of polyurethane rubber is coated on the surface of the metal core roll 26a to a thickness of 4 O mm. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a diameter of 40 O mm and a flat roll peripheral surface was used. When a moisture-adjusting wet paper sheet 20 B was passed between a hard roll 25 and a soft roll 26 constituting the press roll 27 and a linear pressure of 34 kg / cm was applied, the contact length was It was 54 mm. The soft roll 26 is 8 5 against the peripheral speed of the hard roll 25. It was rotated at a speed of% to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6% to obtain stretched paper 20D. The obtained stretched paper 20D had no wrinkles and good stretchability. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Example 6)

As a soft roll 26 with a flat roll surface, which composes the press roll 27, the surface layer 26b of 2-tributadiene rubber is coated on the surface of the metal core roll 26a to a thickness of 25 mm. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a flat 250 mm diameter roll surface was used. When a moisture-adjusting wet paper sheet 20B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27 and a linear pressure of 74 kg / cm was applied, the contact length was 4 8 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6%, to obtain stretched paper 20D. The obtained stretched paper 20D had no wrinkles and good elongation. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Example 7)

As a soft roll 26 having a flat roll peripheral surface constituting the press roll 27, a surface layer portion 26b of polyurethane rubber is coated on the surface of the metal core roll 26a to a thickness of 4 O mm. The same shrinkage imparting device 22 as in Example 3 was used except that a soft roll 26 having a diameter of 40 O mm and a flat roll peripheral surface was used. When a moisture-adjusting wet paper sheet 20B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27, and a linear pressure of 52 kg / cm was applied, a contact length was obtained. The height was 70 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6% to obtain stretched paper 20D. The obtained stretched paper 20D had particularly good elongation, but the power of the shrinkage imparting device 22 was negative. The load was large and the tendency was overload. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Example 8)

As a soft roll 26 with a flat peripheral surface that forms the press roller 27, a polyurethane rubber surface layer 26b is formed on the surface of the metal core roll 26a to a thickness of 40 mm. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a diameter of 40 O mm and a flat roll peripheral surface was used. When a moisture adjusted wet paper sheet 20 B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27 and a linear pressure of 15 kg Z cm was applied, the contact length was 3 1 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6% to obtain stretched paper 20D. The obtained stretched paper 20D had no wrinkles and good stretchability. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Comparative Example 2)

As a soft roll 26 having a flat roll peripheral surface constituting the press roll 27, a surface layer 26b of nitrile butadiene rubber is coated on the surface of a metal core roll 26a to a thickness of 5 mm. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 with a flat roll surface having a diameter of 250 mm was used. When a moisture-adjusting wet paper sheet 20 B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27 and a linear pressure of 74 kg / cm was applied, the contact length was increased. The height was 20 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6%, to obtain stretched paper 20D. A slip was observed between the moisture-adjusting wet paper sheet 20B and the soft roll 26 at the time of the shrinkage treatment, and the obtained stretched paper 20D had little elongation. Table 2 shows the physical properties of the obtained stretched paper 20D. (Comparative Example 3)

The roll surface of the metal core roll 26a is coated with a polyurethane rubber surface layer 26b to a thickness of 40 mm on the surface of the metal core roll 26a as a soft roll 26 having a flat roll peripheral surface constituting the press roll 27. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a diameter of 40 O mm and a flat roll peripheral surface was used. When a moisture-adjusted wet paper sheet 20 B was passed between a hard roll 25 and a soft roll 26 constituting the press roll 27 and a linear pressure of 10 kg / cm was applied, the contact length was 24 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. After that, the water content is 6 in the subsequent drying device 23. /. To obtain a stretched paper 20D. During the shrinkage treatment, a slip was observed between the moisture-adjusting wet paper sheet 20B and the soft roll 26, and the obtained stretched paper 20D had a small elongation. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Comparative Example 4)

As a soft roll 26 having a flat peripheral surface, the press roll 27 is made of a metal core roll 26a, and the surface layer portion 26b of 2-tributadiene rubber is 25 mm thick on the surface of the metal core roll 26a. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a flat diameter of 250 mm and a flat peripheral surface was used. When a moisture adjusted wet paper sheet 20 B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27 and a linear pressure of 42 kg / cm was applied, the contact length was 2 4 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. Thereafter, drying was performed by a drying device 23 in the subsequent stage so that the water content became 6%, to obtain stretched paper 20D. A slip occurred between the moisture-adjusting wet paper sheet 20B and the soft roll 26 during the shrinkage treatment, and sufficient shrinkage could not be imparted. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Comparative Example 5) As a soft roll 26 with a flat peripheral surface that forms the press roller 27, a polyurethane rubber surface layer 26b is formed on the surface of the metal core roll 26a to a thickness of 40 mm. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft mouth 26 having a 40 mm diameter roll and a flat peripheral surface was used. When a moisture control wet paper sheet 20 B was passed between the hard roll 25 and the soft roll 26 constituting the press roll 27 and a linear pressure of 10 kg / cm was applied, the contact length was determined. The height was 24 mm. The soft roll 26 is 85 with respect to the peripheral speed of the hard roll 25. It was rotated at a speed of / ₀ to impart shrinkage. After that, the water content is 6 in the subsequent drying device 23. /. To obtain a stretched paper 20D. During the shrinkage treatment, a slip occurred between the moisture-adjusting wet paper sheet 20B and the soft roll 26, and sufficient shrinkage could not be imparted. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Comparative Example 6)

The surface of the metal core roll 26a is coated with a polyurethane rubber surface layer 26b to a thickness of 40 mm as a soft roll 26 with a flat peripheral surface that forms the press nozzle 27. The same shrinkage imparting device 22 as in Example 3 was used, except that a soft roll 26 having a flat diameter of 400 mm was used. When a moisture-adjusting wet paper sheet 20 B was passed between a hard roll 25 and a soft roll 26 constituting the press roll 27 and a linear pressure of 5 kg / cm was applied, the contact length became 1 1 mm. The soft roll 26 was rotated at a speed of 85% with respect to the peripheral speed of the hard roll 25 to apply shrinkage. After that, it was dried with a drying device 23 in the subsequent stage to a water content of 6% to obtain stretched paper 20D. A slip occurred between the moisture-adjusting wet paper sheet 20B and the soft roll 26 during the shrinkage imparting treatment, and sufficient shrinkage could not be imparted. Table 2 shows the physical properties of the obtained stretched paper 20D.

(Comparative Example 7)

A soft roll with a flat peripheral surface that composes the press port 2 7 2 6 As a metal core roll ² 6 surface layer portion surface of the polyurethane rubber of a 2 6 b is 4 0 mm of being coated to a thickness of a diameter of 4 0 0 mm roll circumferential surface flat soft rolls ² 6 The same shrinkage imparting device 22 as in Example ³ was used, except that was used. When the press rolls ² 7 passed the moisture control wet paper sheet 2 0 B between the hard ^ mouth one le 2 5 and the soft roll 2 6 constituting the, multiplied by the linear pressure ⁷ 0 kg / cm, the contact length of was ⁸ 5 mm. In this case, the power load of the contraction imparting device ^{2 2} becomes overloaded tendency, the peripheral velocity of the soft roll 2 6 with respect to the peripheral speed of the hard roll 2 5

It could not be reduced to 85%, only 90%. This speed is rotating contracts granted then, dried to obtain a stretched sheet 2 0 D so that the ^6% water content at a later stage of the drying device ^{2 3.} At the time of the shrinkage imparting treatment, wrinkles were noticeably generated on the moisture-adjusted wet paper sheet 20B. Table 2 shows the physical properties of the obtained stretched paper 20D.

[Table 2] Basis weight Vertical extension Horizontal extension Contact length Remarks

(g / nf) (%) (%) (mm; Operating conditions Example 3 205 22 20 32 Good Example 4 218 25 22 46 Good Example 5 223 28 24 54 Good Example 6 220 24 22 48 Good Example 7 238 40 26 70 Overload tendency Example 8 200 22 20 31 Good Comparative example 2 1 52 6 10 20 Slip occurrence Comparative example 3 1 62 1 5 12 24 Slip occurrence Comparative example 4 1 54 7 9 24 Slip occurrence Comparative example 5 1 54 7 9 24 Slip occurrence Comparative example 6 1 54 7 9 1 1 Slip occurrence Comparative example 7 187 16 11 85 Overload Next, a third example of the above embodiment will be described based on Examples 9 to 11 and Comparative Examples 8 to 11. In each of Examples and Comparative Examples, papermaking was performed under the following common conditions except for the configuration of the soft roll 36 of the shrinkage imparting device 32. Paper raw material using a general-purpose N-B KP pulp beaten to a freeness of 3 OO ml, and paper so that the setting basis weight on wire 1 5 0 g Zm ^2. The paper machine is a general multi-cylinder fourdrinier paper machine and a schematic diagram is shown in Fig. 11. The shrinkage imparting device 32 was installed at a roughly intermediate position between the drying devices 31 and 33 equipped with more than a dozen cylinder dryers. The shrinkage imparting device 3 2 has a V-shaped circumferential groove 3 having a groove interval A 3 of 1.2 mm, a groove width B 3 of 0.8 mm, and a groove depth C 3 of 1.2 mm. 4 was performed using a combination of a hard roll 35 made of stainless steel provided in the width direction of the mouth and the soft roll 36 used in each of the examples and comparative examples.

The moisture of the wet paper sheet 30A produced in the previous step was adjusted to 40% by the drying device 31 at the previous stage of the shrinkage imparting device 32, and the moisture-adjusted wet paper sheet 30B with the adjusted moisture was removed. Shrinkage was given by the shrinkage imparting device 32, and the shrinkage-treated wet paper sheet 30C that had shrunk was dried by the drying device 33 so that the moisture content became 6% to obtain stretched paper 30D.

The wear resistance and the amount of compressive deformation of the surface layer 36b and the inner layer 36c of the soft roll 36 were measured by the following methods.

• Abrasion resistance measurement method = Pre-abrasion: 300 times, main test: 100 times, load: 27.0 N, wheel angle: 15 ° The wear loss capacity was measured and evaluated under the conditions.

• Method of measuring compression deformation, method = 60 mmX 50 mmX Deformation when a 10 mm thick rubber specimen is compressed at a compression rate of 10 mm / min with a stress of 1.5 kN. The amount was measured. That is, the amount of deformation when compressed at a pressure of 1.5 kN / 300 mm ² = 0.5 MPa is measured.

(Example 9)

The shrinkage imparting device 32 includes a hard roll 350 having a diameter of ²⁰⁰ mm made of stainless steel provided with a groove 34 and a metal core roll having a diameter of 180 mm. The surface of 36a is made up of a surface layer 36b made of polyurethane rubber with a wear resistance of 0.02 cc Z100 with a thickness of 2 mm, and a nitrile pig with 8% compression deformation. A press roll 37 consisting of a soft roll 36 having a flat peripheral surface and covered with a two-layer structure of an inner layer 36 c formed of 18 mm thick rubber is provided. The moisture adjusted wet paper sheet 30 B is passed between the hard roll 35 and the soft roll 36 constituting the press mouth 37, and a linear pressure of 25 kg Z cm is applied. The peripheral speed of the roller was equal to that of the cylinder dryer of the drying device 31 before the shrinkage treatment, and the soft mouth 36 was rotated at a speed of 85% of the peripheral speed of the hard roll 35 to shrink. Thereafter, the paper was dried with a drying device 23 in the subsequent stage so that the water content became 6%, to obtain stretched paper 30D. Table 3 shows the physical properties of the obtained stretched paper 30D.

(Example 10)

The surface of a metal core roll 36a having a diameter of 180 mm is used as the soft roll 36 of the shrinkage imparting device 32, and a two-tributadiene having a wear resistance of 0.04 cc Zl100. A roll layer coated with a two-layer structure consisting of a surface layer 36 b formed of rubber with a thickness of 2 mm and an inner layer 36 c formed of nitrile butadiene rubber with a compression deformation of 8% with a thickness of 18 mm Extensive paper 30D was obtained in the same manner as in Example 9 except that a soft roll 36 having a flat surface was used. Table 3 shows the physical properties of the obtained stretched paper 30D.

(Example 11)

As the soft roll 36 of the shrinkage imparting device 32, the surface of a metal core roll 36a having a diameter of 180 mm is coated with polyurethane rubber having a wear resistance of 0.02 cc / 100 mm. The roll surface covered with a two-layer structure consisting of a surface layer part 36 b formed with a thickness and an inner layer part 36 c formed of nitrile butadiene rubber with a compression deformation of 6% with a thickness of 14 mm is flat. Extensive paper 30D was obtained in the same manner as in Example 9, except that the soft roll 36 was used. Table ³ shows the physical properties of the obtained stretched paper 30D.

(Comparative Example 8) As the soft roll 3 6 shrinkage applying device 3 2, the surface of the metal core roll 3 6 a diameter 1 8 0 mm, 2 abrasion resistance 0. 0 c _C l 0 0 1 0 a polyurethane rubber 0 Roll surface covered with a two-layer structure consisting of a surface layer 36 b formed with a thickness of mm and an inner layer 36 c formed of nitrile butadiene rubber with a compressive deformation of 8% with a thickness of 10 mm is flat Extensive paper 30D was obtained in the same manner as in Example 9, except that a soft soft mouth 36 was used. Table 3 shows the physical properties of the obtained stretched paper 30D.

(Comparative Example 9)

As the soft mouth 36 of the shrinkage imparting device 32, the surface of a metal core mouth 36a having a diameter of 180 mm is formed with a wear resistance of 0.1 I 2 cc / 100 Coated with a two-layer structure consisting of a surface layer 36 b formed of 4-mm thick tributadiene rubber and an inner layer 36 c formed of 16 mm thick di-butadiene rubber with 8% compression deformation. A stretched paper 30D was obtained in the same manner as in Example 9, except that a soft mouth 36 having a flat roll peripheral surface was used. Table 3 shows the physical properties of the obtained stretched paper 30D.

(Comparative Example 10)

As the soft roll 36 of the shrinkage imparting device 32, the surface of a metal core roll 36a having a diameter of 180 mm is formed with a wear resistance of 0.02 cc / l 00 and a compressive deformation amount of Example 9 was the same as Example 9 except that a soft roller 36 having a flat roll surface coated with a single-layer structure of the surface layer 36b formed of 2% polyurethane rubber with a thickness of 20 mm was used. Similarly, stretched paper 30D was obtained. Table 3 shows the physical properties of the obtained stretched paper 30D.

(Comparative Example 11)

As the soft roll 36 of the shrinkage imparting device 32, the surface of a metal core roll 36a having a diameter of 180 mm is used. The wear resistance is 0.1 Icc / 100, and the amount of compressive deformation is The same procedure as in Example 9 was carried out, except that a soft roll 36 having a flat surface was used, which was covered with a single layer structure of a surface layer portion 36b formed of 20% of nitrile butadiene rubber of 8% in thickness of 20 mm. To obtain a stretched paper 30D. Table 3 shows the physical properties of the obtained stretched paper 30D. [Table 3]

Stretched paper 30D obtained by the production methods of Examples 9 to 11 exhibited high elongation of 20% or more in both the length and width directions, and no change was observed in the roll appearance of the soft roll 36. . In Comparative Example 8, no change was observed in the appearance of the mouth of the soft roll 36, but the effect of imparting the desired shrinkage was inferior and was not suitable for practical use. In Comparative Example 9, twist marks occurred on the roll surface of the soft roll 36 in a short operation, and wear debris was partially generated, resulting in poor practicality. Comparative Example 10 showed no change in the roll appearance of the soft roll 36, but was not suitable for practical use because slip occurred and the effect of imparting the desired shrinkage was inferior. In Comparative Example 11, wear debris was generated from the roll surface of the soft roll 36 in a short operation, which was not suitable for practical use. Next, a fourth example of the above embodiment will be described based on Examples 12 to 14 and Comparative Examples 12 to 14. In each of the examples and comparative examples, the shrinkage imparting device 42 is made of stainless steel provided with a V-shaped groove having a groove interval of 1.2 mm, a groove width of 0.8 mm, and a groove depth of 1.2 mm in a circumferential direction. And a press roll 47 comprising a soft roll 46 made of -tolylbutadiene rubber having a flat peripheral surface. Moisture adjusted moisture paper between the hard roll 45 and the soft roll 46 of the press roll 47 The sheet 40B was passed through, a linear pressure of 50 kg / cm was applied, and the soft roll 46 was rotated at a speed of 75% with respect to the peripheral speed of the hard roll 45 to give shrinkage.

(Example 1 2)

The raw material is 100% bleached softwood bleached kraft pulp, with a freeness of C S F

310 ml, basis weight on wire 150 g / m ² , moisture in paper during shrinkage treatment 32 /. The wet-adjusted wet paper sheet 40 B having a wet paper strength of 2.5 kN / m is passed through the shrinkage applying device 42 while applying an appropriate tension to the shrinkage treatment under the above-mentioned constant conditions, and the drying device 4 Drying with 3 yielded stretched paper 40D. Then, it was wound by a winding device. At the time of the shrinkage treatment, the shrinkage treatment could be performed without any wrinkles. Table 4 shows the physical properties of the obtained stretched paper 40D.

(Example 13)

4 5 0 ml, a wire Uetsubo amount 1 5 0 g / m ^2, the paper in water is 3 to 7% of the shrinking treatment, moisture control of the wet paper strength 1. 5 k N / m wet paper sheet 4 0 B The paper was passed through a contraction applying device 42 while applying an appropriate tension, subjected to a contraction treatment under the above-mentioned constant conditions, and dried by a drying device 43 to obtain stretched paper 40D. Then, it was wound up by a winding device. At the time of the shrinkage treatment, the shrinkage treatment could be performed without any wrinkles. Table 4 shows the physical properties of the obtained stretched paper 40D.

(Example 14)

Raw materials are softwood bleached kraft pulp Z hardwood bleached kraft pulp =

50% / 50. /. The freeness is CSF 300 m 1, the basis weight on the wire is 70 g / m ² , the moisture content in the paper during shrinkage treatment is 28%, and the wet paper strength is 0.7 k NZm. The paper sheet 40B is passed through the shrinkage imparting device 42 while applying an appropriate tension, subjected to the shrinkage treatment under the above-mentioned constant conditions, and dried in the drying device 43 to obtain expanded paper 40D. Was. Then, it was wound up by a winding device. During the shrinking process, the shrinking process is performed without wrinkles at all. Could be managed. Table 4 shows the physical properties of the obtained stretched paper 40D.

(Comparative Example 1 2)

Raw material is hardwood bleached kraft Toparupu 1 0 0% freeness CSF 5 0 0 m 1, wire Uetsubo amount 1 0 0 g / m ² in the process at the paper in water 3 9%, wet paper strength A 0.2 k NZ m moisture-adjusted wet paper sheet 40 B is passed through the shrinkage imparting device 42 while applying tension, subjected to a shrinkage treatment under the above-mentioned constant conditions, dried by a drying device 43 and stretched paper 4. Got 0D. After that, it was wound by a winding device. During the shrinking process, wrinkles were generated, and the paper was cut when the tension was increased as a measure against wrinkles. Table 4 shows the physical properties of the obtained stretched paper 40D.

(Comparative Example 13)

Raw material is 1 0 0% softwood bleached kraft pulp, freeness CSF 2 5 0 m 1, wire Uetsubo amount 2 0 0 g / m ² in the process at the paper in water 1 8%, the wet paper strength 6.3 k Ν ιιη Moisture adjusted wet paper sheet 40 B is passed while applying an appropriate tension to shrinkage imparting device 42, subjected to shrinkage treatment under the above-mentioned constant conditions, and dried by drying device 43. Stretched paper 40D was obtained. Then, it was wound by a winding device. No wrinkles occurred during the shrinkage treatment, but sufficient shrinkage could not be applied. Table 4 shows the physical properties of the obtained stretched paper 40D.

(Comparative Example 14)

The raw material is 100% softwood bleached kraft pulp, with a freeness of CSF 250 m 1, a top weight of wire 200 g / m ² and a paper moisture of 54% when processed, wet paper strength. The 3.2 K NZ m moisture-adjusted wet paper sheet 40 B is passed through the shrink applying device 42 while applying an appropriate tension, subjected to the shrinking treatment under the above-mentioned constant conditions, and dried by the drying device 43. Stretched paper 40D was obtained. Then, it was wound by a winding device. No wrinkles occurred during the shrinkage treatment, but sufficient shrinkage could not be applied. Table 4 shows the physical properties of the obtained stretched paper 40D. [Table 4]

As described above, according to the present invention, a hard roll in which grooves along the circumferential direction are provided on the roll peripheral surface at predetermined intervals in the width direction of the mouth and a soft roll in which the peripheral surface of the mouth is flat. A pair of press rolls comprising: a shrinkage imparting device configured to rotate with a peripheral speed of the soft roll being lower than a peripheral speed of the hard roll under pressure, and a basis weight of 35 g / m ² 450 g Zm ² with wet paper strength of 0.1 lk N / m 2.0 kN / m By passing the moisture-adjusting wet paper sheet adjusted to the range described above to shrink the moisture-adjusting wet paper sheet, and then drying it, it is possible to easily obtain a stretched paper exhibiting an elongation of 20% or more in both length and width. It is economical because a general-purpose paper base can be used as the sheet-shaped paper base.

Further, according to the present invention, a pair of press rolls composed of a hard roll in which grooves along the circumferential direction are provided on the roll circumferential surface at predetermined intervals in the roll width direction and a soft roll having a flat roll circumferential surface are provided. A contact length between the hard roll and the soft roll during pressurization is 3 Omm or more and 8 Omm or less, and a peripheral speed of the soft roll with respect to a peripheral speed of the hard roll under pressure The paper is passed through a moisture-adjusting wet paper sheet having a water content of 20% and 50% through a shrinkage imparting device that is rotated at a lower speed. By applying shrinkage to the paper sheet and then drying it, the abrasion resistance of the soft roll is improved, and it is easy to obtain stretched paper with elongation characteristics of 20% or more in longitudinal elongation and 20% or more in lateral elongation. be able to.

In addition, in producing stretched paper, only the shrinkage imparting device of the present invention need be installed in a general-purpose paper machine, so that equipment costs are low and economical.

Further, according to the present invention, a pair of press rolls composed of a hard roll and a soft roll having a flat roll peripheral surface are provided with grooves along the circumferential direction at predetermined intervals in the roll width direction. The soft roll has a two-layer structure in which a surface layer made of a material having excellent abrasion resistance and an inner layer part made of a material which is easily deformed under pressure are integrated. The paper is passed through a moisture-adjusting wet paper sheet having a paper moisture content of 20% to 50% through a shrinkage imparting device configured to rotate the soft roll at a lower peripheral speed than the peripheral speed. By imparting shrinkage to the moisture-adjusting wet paper sheet and then drying it, the effect of imparting shrinkage and durability of the soft roll can be improved, and the elongation characteristics are 20% or more in longitudinal elongation and 20% in lateral elongation. The above-described stretched paper can be easily obtained, and the durability is improved. Being able to improve is economical in practice.

Further, according to the present invention, a pair of press ports comprising a hard roll having a circumferential groove formed on the roll circumferential surface at predetermined intervals in the roll width direction and a soft roll having a flat roll circumferential surface. The shrinkage imparting device, which has a peripheral weight of the soft roll lower than the peripheral speed of the hard roll under pressure and rotates, has a basis weight of 50 g Zm ² to 450. in the range of gm ^2, in a range in paper moisture of 2 0% to 50%, wet paper strength of paper direction in the moisture range of Katsuso is 0. 3 k N / m or more der Ru moisture adjusted wet paper By passing the sheet and giving the moisture-adjusted wet paper sheet shrinkage, and then drying it, pre-molding is not required, and It is possible to stably, easily and economically produce stretched paper exhibiting an elongation of 20% or more in both length and width without generating wrinkles or breakage during shrinkage treatment.

Claims

The scope of the claims

1. A pair of press rolls consisting of a hard roll and a soft roll having a flat circumferential surface are provided on the roll circumferential surface with grooves along the circumferential direction at predetermined intervals in the roll width direction. The contact length between the hard roll and the soft roll is 3 Omm or more and 8 Omm or less, and the peripheral speed of the soft roll is reduced with respect to the peripheral speed of the hard roll under pressure to rotate. The moisture-adjusting wet paper sheet having a moisture content in the paper of 20% to 50% is passed through a shrinkage imparting device configured to perform the shrinking, and the moisture-adjusting wet paper sheet is shrunk, and then dried. And a method for producing stretched paper.

2. A pair of press pallets comprising a hard roll provided with grooves along the circumferential direction at predetermined intervals in the roll width direction on the roll peripheral surface and a soft roll having a flat pallet peripheral surface, The soft roll has a two-layer structure in which a surface layer portion made of a material having excellent wear resistance and an inner layer portion made of a material which is easily deformed under pressure are integrated. The moisture adjustment is performed by passing a moisture-adjusting wet paper sheet having a moisture content in the paper of 20% to 50% through a shrinkage imparting device configured to rotate the soft roll at a lower peripheral speed than the speed. A method for producing stretched paper, comprising shrinking a wet paper sheet and thereafter drying the wet paper sheet.

3. The soft roll has a surface layer made of a material having a wear resistance of less than 0.05 cc Z100, and an amount of compressive deformation when the inner layer is compressed at a pressure of 0.5 MPa. 3. The method for producing stretched paper according to claim 2, wherein the material comprises 4% or more of the material.

4. The ratio of the thickness of the surface layer portion to the inner layer portion of the soft roll is as follows: surface layer portion: inner layer portion = 5 × 95: 30/70. The method for producing a stretched paper according to the above item.

5. The material of the surface layer and / or the inner layer of the soft roll is made of any of polyurethane rubber, chloroprene rubber, nitrile / lebutadiene rubber, silicone rubber, polysanolefide rubber, trilinole rubber, and picronolédrien rubber. Claims 2 and 3 Item 5. The method for producing stretched paper according to item 4 or.

6. A pair of press jaws consisting of a hard roll and a soft roll with a flat roll peripheral surface are provided on the peripheral surface of the jaw with grooves along the circumferential direction at predetermined intervals in the roll width direction. , the shrinkage imparted apparatus adapted to rotate at slow circumferential velocity of the soft roll against the peripheral speed of the hard roll under pressure, a basis weight of ^{3 5 g / m 2 ~4 5} 0 g / m 2 And the wet paper strength is 0. lk N / n! Moisture-adjusting wet paper in which the water content in the paper is adjusted to a range of 20% to 50% by using a moisture-applying device. A method for producing stretched paper, which comprises shrinking a paper sheet and then drying it.

7. The stretched paper according to claim 6, wherein the moisture imparting device is any one of a roll coating system, a printing system, an impregnation system, and a spraying system, or a combination thereof. Production method.

8. The groove of the hard roll along the circumferential direction is 0.6 mm to 0.8 mm in the roll width direction, and Φ 畐 0.3 mn! Claims 1, 2, 3, 3, 4, 5, and 6 characterized by having a thickness of 0.5 mm to 1.5 mm and a depth of 0.5 mm to 2.0 mm. Or the method for producing stretched paper according to paragraph 7.

9. A pair of press rolls consisting of a hard roll having grooves along the circumferential direction at predetermined intervals in the roll width direction and a soft roll having a flat circumferential surface on the knurl. In a shrinkage-applying device in which the peripheral speed of the soft roll is reduced by rotation with respect to the peripheral speed of the hard roll under pressure, a basis weight of 50 g / m ² to 450 g Zm ² is applied. Paper with a moisture content in the range of 20% to 50% and a wet paper strength in the papermaking direction in the moisture range of 0.3 kN / m or more. Shrinking the moisture-adjusting wet paper sheet and drying the sheet afterwards.

10 0. The grooves along the circumferential direction of the hard roll are arranged at intervals of 0.5 mm to 1.8 mm in the roll width direction, 0.3 mm to 1.5 mm in width, and deep 10. The method for producing stretched paper according to claim 9, wherein the thickness is 0.5 mm to 2.0 mm.

1 1. The linear pressure between the hard roll and the soft roll is 10 kg Z cm

Claims characterized by being under a pressure of 70 kg / cm. Claims 1, 2, 3, 4, 5, 6, 7, 8 13. A method for producing a stretched paper according to paragraph 9, 9 or 10.

1 2. The circumferential speed of the soft roll with respect to the circumferential speed of the hard roll is such that the circumferential speed of the soft roll is equal to the circumferential speed 1 of the hard roll.

Claims 1, 2, 3, 3, 4, 5, 6, 7, 8 and 9 characterized by the range of 0.95-0.5. 13. A method for producing a stretched paper according to paragraph 9, paragraph 10, paragraph 10, or paragraph 11.