JP2005133262A - Roll of newsprint paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rolls of newsprint paper having high tear strength. <P>SOLUTION: The roll of newsprint paper is produced by winding the newsprint paper having a basis weight of 46 to 38 g/m<SP>2</SP>and the hardness (R) of the rolled paper is 40 to 60 according to JAPAN TAPPI paper pulp testing method No. 37. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a newsprint-printed web which is rolled up by rolling up newsprint with a weight of 46 to 38 g / m ² .

Newspaper has been reduced in weight for the purpose of reducing transportation costs. The movement of weight reduction has shifted from about 49g / m ² to about 46g / m ² due to the second weight reduction around 1980, and then the third weight reduction around 1989 due to the third weight reduction. There has been a shift from 46 g / m ² to newspaper paper with a weight of about 43 g / m ² (also called ultralight newsprint). Since entering the 1990s, the weight has been rapidly reduced, and due to the fourth weight reduction since 1995, it is now shifting to newspaper paper (ultra-lightweight newsprint) with a weight of 40 g / m ² .

In reducing the weight of newsprint, it is necessary to improve various problems associated with the decrease in strength. Conventionally, however, the main problem due to the decrease in strength was a paper break that occurred when printing on a rotary press, resulting in insufficient strength. Improvements have also been made with a focus on this point.
JP 2001-226896 A JP 2002-161493 A JP 2002-173896

  However, along with the rapid weight reduction in recent years, there has been a new problem that the web on the surface of the web is torn and the paper on the surface of the web is torn when transporting the roll of web for newspaper printing after paper making. Such countermeasures against tearing of the web for newspaper printing have been demanded as countermeasures against damaged paper. And, as a countermeasure against paper breakage in a roll for newspaper printing rolls, the addition and application of a surface coating agent containing a paper strength enhancer or silica, which has been mainly performed as a measure for improving strength shortage in the past, The present inventors have found that the effect is small and not suitable for high cost.

  Accordingly, a main object of the present invention is to provide a web for newspaper printing that is difficult to tear during transportation, storage, and movement, and that does not easily flake off at the winding end.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A newspaper-printing web which is rolled up by rolling up a newspaper with a weight of 46-38 g / m ² ,
JAPAN TAPPI Paper Pulp Test Method No. A web for newspaper printing, wherein the web has a hardness (R) measured based on 37 of 40 to 60.

<Invention of Claim 2>
The web for newspaper printing according to claim 1, wherein a dynamic friction coefficient based on JIS P 8147 of the newspaper is 0.45 to 0.65.

<Invention of Claim 3>
The newspaper for newsprint according to claim 1 or 2, wherein the newsprint is adjusted to a coefficient of dynamic friction in the range of 0.45 to 0.65 by a smoothing process passing between a metal roll and an elastic roll.

<Invention of Claim 4>
The web for newspaper printing according to any one of claims 1 to 3, wherein the newsprint is not surface-treated with a coating liquid containing silica.

In accordance with the present invention, the JAPAN TAPPI paper pulp test method No. 1 is used for newsprint webs rolled up in a roll shape from newspaper paper having a basis weight of 46 to 38 g / m ² . When the hardness (R) of the web measured based on 37 is 40 to 60, tears caused by the collision between roll papers during transportation are significantly reduced. Further, when the dynamic friction coefficient of the newsprint based on JIS P 8147 is 0.45 to 0.65, the friction when the roll papers come into contact with each other is reduced, and the newsprint printing webs are rubbed against each other. It is hard to break.

  On the other hand, it can be achieved through the space between the metal roll and the elastic roll in order to set the dynamic friction coefficient within the above range.

  Furthermore, the newsprint of the present invention can be manufactured at a low cost without using a surface treating agent because sufficient strength is exhibited even if it is not surface-treated with a coating liquid containing colloidal silica or the like on the front and back surfaces. Is desirable.

Next, the best mode for carrying out the present invention will be described below.
The web for newspaper printing according to the present invention is a roll of newspaper paper having a basis weight of 43 to 38 g / m ² . The hardness (R) of the web measured based on 37: 2000 (winding paper hardness test method) is 40-60.

Newspaper paper with a weight of less than 38 g / m ² is currently difficult to manufacture, and the JAPAN TAPPI paper pulp test method no. Even if the hardness (R) of the web measured based on 37 is 40-60, it is difficult to avoid tearing. Also, it does not cause a tear of the problem at present in the newsprint in excess of 46g / m ^2.

The raw material of the newspaper and the paper making method are not particularly limited. What is necessary is just to adjust and adjust the rice paper weight to 46-38 g / m < ² > by the conventionally well-known newspaper papermaking method.

  There is no limitation on the method of winding the newspaper after paper making into a web for newspaper printing. According to a conventional newsprint paper manufacturing method, newsprint paper flowing from a paper machine can be wound using a winder. Here, JAPAN TAPPI paper pulp test method no. When the hardness (R) of the web measured in accordance with 37 is in the range of 40 to 60, the winding speed and tensile strength in a winder (winder) are appropriately selected according to the characteristics of the newspaper after papermaking. What is necessary is just to adjust (tension). About processing of the winding end of the web for newspaper printing, a method of stopping at 5 to 7 points with an adhesive tape having a width of 25 to 50 mm, or processing by stopping the winding end at one character with an adhesive tape.

  On the other hand, JAPAN TAPPI paper pulp test method no. When the hardness (R) of the web measured based on 37 is less than 40, the roll hardness is so soft that when the rolls collide with each other, the roll shape is deformed and suitable newspaper printing cannot be performed. On the other hand, if the repulsion degree exceeds 60, the winding hardness is too hard and the impact when the rolls collide with each other is so strong that breakage tends to occur.

  Here, JAPAN TAPPI paper pulp test method no. 37, it is determined that the measurement is performed over the entire width at intervals of 5 to 10 cm as necessary, but in the present invention, the measurement is performed over the entire width at intervals of 70 mm in consideration of the width of a general newspaper web. Is preferred.

  The size of the roll paper for printing is not particularly limited, but considering the size of the newspaper printing machine, it is a cylinder having a core diameter of 100 to 120 mm, a diameter of 800 to 1300 mm, and a width of 813 to 1,626 mm.

  On the other hand, it is desirable for the newspaper printing web of the present invention to have a coefficient of dynamic friction based on JIS P 8147 of the newspaper of 0.45 to 0.65. If the coefficient of kinetic friction is less than 0.45, slippage and flow are likely to occur in the roll of a newspaper rotary press, causing text duplication and misregistration. Tearing due to the polishing between the papers located at the center and the winding end portion are likely to be broken. In adjusting the dynamic friction coefficient in the range of 0.45 to 0.65, it can be adjusted by a conventionally known method in addition to a method of adding a friction coefficient adjusting agent made of hydrated silicate for papermaking. It is preferable that the wet newsprint newspaper be adjusted by applying a calendar process in which the newsprint is passed between a metal roll and an elastic roll. Adjustment of the coefficient of friction by the addition of chemicals increases the paper density, so that the paper tends to become loose and it is difficult to improve the strength. In addition, according to such a method, it is possible to manufacture without decreasing the opacity because it is difficult to reduce the bulk, and the manufacturing cost is also reduced.

Next, examples of the present invention will be described. While producing newsprint paper with a basis weight of 35 to 49 g / m ² using a paper machine, these newsprint papers were wound up by adjusting the tension of the winder, and the JAPAN TAPPI paper pulp test method no. Several types of webs for newspaper printing (Examples 1 to 4 and Comparative Examples 1 to 4) having different web paper hardness (R) measured based on 37-2000 were prepared. The size of each newspaper printing web was 110 mm in core diameter, 1,150 mm in diameter × 1,626 mm in width. The winding end was processed with a commercially available 30 mm wide adhesive tape conventionally used to stop the winding end portion, and the end portion was fixed to the width direction by 5 points. The tensile strength in the dry state of each newspaper printing web was adjusted to be approximately the same by adding a paper strength enhancer during paper making. About the web for newspaper printing concerning each of these Examples and each comparative example, the ease of tearing at the time of roll collision and the ease of flaking were tested. In addition, JAPAN TAPPI paper pulp test method No. In conducting the hardness test of the 37-2000 web, a Schmitt hammer manufactured by procedq was used.

<Test 1A>
As shown in FIG. 1, two newspaper printing webs R ₁ and R _{2 according} to Example 1 are placed 3 m apart from each other and placed on a flat tilt table X having a flat tilt angle of 5 °, and R ₂ is naturally positioned. The operation of causing the collision by rolling was repeated, and the number of times of collision was measured to determine whether the break and the break occurred.

Incidentally, R ₁ is the curved stopper S of the placed width 1,500mm to interview R ₁ on the side opposite to the side facing the R _2, the side facing the R ₂ when it hits the R ₂ It is fixed so that it does not move to the opposite side.

  As shown in Table 1, a web for newspaper printing having a winding hardness of 40 to 60 and a dynamic friction coefficient in the range of 0.45 to 0.65 has a result that the winding surface layer is not easily broken or broken. It was.

  It can be used for a web for newspaper printing used for newspaper printing.

It is explanatory drawing for demonstrating the test of the Example which concerns on this invention.

Explanation of symbols

  R ... roll for newspaper printing, 1 ... newspaper, 2 ... winding end, 3 ... core, 4 ... adhesive tape.

Claims (4)

A newspaper-printing web which is rolled up by rolling up a newspaper with a weight of 46-38 g / m ² ,
JAPAN TAPPI Paper Pulp Test Method No. A web for newspaper printing, wherein the web has a hardness (R) measured based on 37 of 40 to 60. The web for newspaper printing according to claim 1, wherein a coefficient of dynamic friction based on JIS P 8147 of the newspaper is 0.45 to 0.65. The newspaper for newsprint according to claim 1 or 2, wherein the newsprint is adjusted to a coefficient of dynamic friction in the range of 0.45 to 0.65 by a smoothing process passing between a metal roll and an elastic roll. The web for newspaper printing according to any one of claims 1 to 3, wherein the newsprint is not surface-treated with a coating liquid containing silica.

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