JP4039502B2 - Newspaper paper for multicolor printing press - Google Patents

Description

【００２５】
参考例４〜５，比較例４〜５
再循環弁開度を３０％に、Ｊ／Ｗ比を９９％にそれぞれ固定し、紙料のろ水度を変化させて繊維配向角及びα方向の浸水伸度が異なる新聞用紙を製造した。
これらの各新聞用紙の平行四辺形化度（Ｐ／Ｍ）と繊維配向角とα方向の浸水伸度と画線ズレとを測定した処、表２に示すように平行四辺形化度が０.０５以下であれば線ズレは良好であった。
【００２６】
【表２】

【００２７】
実施例１〜２，比較例６〜８
ろ水度１６０ｍｌの紙料を用い、再循環弁開度を３０％に固定し、Ｊ／Ｗ比を変化させて繊維配向角及びα方向の浸水伸度が異なる新聞用紙を製造した。
これらの各新聞用紙の平行四辺形化度（Ｐ／Ｍ）と繊維配向角とα方向の浸水伸度と画線ズレとを測定した処、表３に示すように抄紙方向に対する紙の繊維配向角の絶対値が６度以下及び紙の浸水伸度の最も大きい方向の浸水伸度値が５％以下であり、且つ平行四辺形化度が０.０５以下であれば線ズレは良好であった。
【００２８】
【表３】

【００２９】
【発明の効果】
以上に詳述した如く、本発明の多色刷平版輪転機用新聞用紙は、吸水時における平行四辺形化度が小さいので、新聞用紙の印刷に多色刷平版輪転印刷機を用いた場合のペースター後における画線のズレを著しく改善することができるものであり、その工業的価値の非常に大きなものである。
【図面の簡単な説明】
【図１】 紙の平行四辺形化度を測定する前に状態を示す説明図である。
【図２】 図１に示した状態の紙を２０℃，８０％Ｒ.Ｈ.に４時間以上放置した場合における状態の１例を示す説明図である。
【図３】 図１に示した状態の紙を２０℃，８０％Ｒ.Ｈ.に４時間以上放置した場合における状態の他の例を示す説明図である。
【符号の説明】
Ｗ ２０℃，６５％Ｒ.Ｈ.に４時間以上放置した紙からその長さ方向が抄紙方向と一致するように採取した試料の幅
２Ｗ ２０℃，６５％Ｒ.Ｈ.に４時間以上放置した紙からその長さ方向が抄紙方向と一致するように採取した試料の抄紙方向の長さ
ΔＷ ２０℃，８０％Ｒ.Ｈ.環境下における上下の紙の幅方向のズレ長さ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image printed in the first printing section immediately after a paster (paper splicing from a paper winding during printing to the next new paper winding) when used in a multicolor lithographic rotary printing press for printing newsprint. The present invention relates to newsprint paper for a multicolor lithographic rotary printing press with a small amount of paper loss based on image line misalignment printed in the second and subsequent printing sections.
[0002]
[Prior art]
In recent years, newsprint printing technology has made great progress such as offset printing, color printing, high-speed mass printing, and automation. Along with this, improvements in various physical properties are also required for newsprint paper from the viewpoint of workability and printability.
[0003]
Paper used for printing is obtained by dewatering and drying a dispersion in water obtained by beating pulp fibers of mechanical pulp or chemical pulp, and bonding the fibers to each other by hydrogen bonding. There are newsprints, etc., mainly.
[0004]
When the pulp fibers absorb water or absorb moisture, the dimensional change in the cross-sectional direction of the pulp fibers is several tens of times larger than the dimensional change in the length direction. The dimensional change due to moisture absorption greatly extends in the width direction.
[0005]
On the other hand, lithographic printing is the most widely used plate type because it is easy to handle and can perform multi-color overprinting with high precision because the image area and non-image area are printed with the same height. In this method, printing is performed using the property that oil-based ink and water repel each other, and the lithographic printing machine has an ink supply unit and a dampening water supply unit that supplies water thinly to the plate surface. ing. In lithographic printing, the image area is printed with ink when the paper passes through the printing area, and the non-image area is stretched with water, and the printed image area is also expanded and deformed accordingly. Therefore, when a multicolor lithographic printing machine having two or more printing parts prints image lines sequentially on the same paper, the image lines printed by the first printing part and the second and subsequent printing parts are printed. Deviation occurs in the image line.
[0006]
In order to eliminate misalignment of the printed image line due to paper expansion due to water absorption or moisture absorption and to align the image line, Japanese Patent Application Laid-Open No. 6-134959 discloses a width in one direction of the paper traveling toward the printing unit. Disclosed is a method for correcting by pressing an appropriate portion of the direction to form a wave substantially parallel to the longitudinal direction, and automatically correcting within a certain registration error while minimizing misalignment during printing. Therefore, a means for automatically adjusting the misregistration of the printing register by moving the plate cylinder by the register control means for controlling the register of the printing portion by arranging a detector for reading the printed register mark is disclosed. This is disclosed in Japanese Patent No. 186374.
[0007]
By using such a conventional printing machine, it has become possible to satisfactorily perform image line misalignment control in one paper winding. However, a conventional apparatus having an apparatus for performing such image line misalignment control has been achieved. In the printing machine of the past, when printing a paper joint from the paper winding while printing newsprint to the next new paper winding, the lines printed in the first printing section and the second and later in multicolor lithographic printing A large misalignment occurred between the image printed on the printing section and a large amount of waste paper was discharged to adjust the misalignment.
[0008]
[Problems to be solved by the invention]
The present invention reduces the misalignment of the image line immediately after the paster when printing continuous image lines on newsprint with a multi-color printing lithographic printing press having two or more printing sections using fountain solution as described above. Another object of the present invention is to provide newsprint paper for a multi-color lithographic rotary printing press that reduces the amount of damaged paper.
[0009]
[Means for Solving the Problems]
As a result of diligent investigations to solve such problems, the present inventors have found that the misalignment of the image line immediately after the paster has an incomplete parallelogram shape in which the paper extends in the width direction due to water absorption or moisture absorption and is biased to one side. As the printing progresses, the paper pass line shifts in the direction of the parallelogram, and the position and displacement of the plate cylinder occur. Therefore, a new index indicating the degree of displacement in the width direction of the paper before and after moisture absorption When the degree of shape is set, and it is large, it is found that there is a large misalignment of the image line. If the degree of parallelogram formation of the paper at the time of moisture absorption is within a specific range, the amount of change in the paper pass line after the paster The present invention was reached by investigating that the amount of deviation from the position of the plate cylinder was small.
[0010]
That is, multicolor lithographic rotary printing machine newsprint according to the present invention, the largest direction of the water elongation value of the absolute value of 6 degrees or less及beauty paper water elongation of the fiber orientation of the paper with respect to machine direction is 5% The parallelogram shape degree, which is a new index from the viewpoint of reducing the amount of paper loss and reducing the amount of paper loss during the paster, was left at 20 ° C. and 65% RH for 4 hours or more. A paper having a width of W and a length of 2 W was collected so that the length direction coincided with the paper making direction, and folded in the middle in the length direction of the paper at 20 ° C. and 80% RH. Parallelogram degree of paper (P / M) obtained by the following formula when left for more than an hour
P / M (% /%) = {(ΔW / 2W) × 100} / (M ₂ −M ₁ )
ΔW: 20 ° C., 80% RH in the width direction misalignment length of the upper and lower papers M ₁ : Water content in paper at 20 ° C., 65% RH (%)
M ₂ : moisture in paper (%) at 20 ° C. and 80% RH
Is 0.05 or less. In particular, when it is desired to reduce color misalignment and improve the sharpness of the image area, it is preferably 0.03 or less.
[0011]
And, for such newsprint paper for a multicolor lithographic rotary printing press according to the present invention in which the parallelogram degree (P / M) of the paper is 0.05 or less, the absolute value of the fiber orientation angle of the paper is the paper making direction. to 6 degrees or less, more preferably it is desirable to below 4 degrees, and even most flooded 5% or less under a water elongation in a large listening direction elongation of the paper, it is desirable that more preferably below 4% I also investigated .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, an explanation will be given of the degree of parallelogram formation of an important paper in newsprint paper for a multicolor lithographic printing press according to the present invention.
When performing multicolor lithographic printing of newsprint on a multicolor lithographic rotary printing press, the inventors of the present invention have an image line printed in the first printing section immediately after the paster and an image printed in the second and subsequent printing sections. As a result of various studies on the reason why a large misalignment was generated in the meantime and a large amount of damaged paper was discharged to adjust the misalignment, it was found that the cause is that the paper becomes a parallelogram at the time of water absorption.
[0013]
Therefore, as a result of various investigations on the cause of the phenomenon that the paper becomes a parallelogram, it was found that parallelogram formation occurs when the fiber orientation angle of the paper is different from the paper making direction. This is because when the pulp fiber constituting the paper absorbs or absorbs moisture, the dimensional change in the cross-sectional diameter direction is generally several tens of times larger than the dimensional change in the length direction. This is because the fiber orientation angle of paper is represented by the main orientation direction of pulp fibers relative to the paper making direction of paper, and the smaller absolute value of the angle is the parallelogram of paper at the time of water absorption. It was discovered that the degree of conversion becomes smaller.
[0014]
Furthermore, the present inventors have also found that the phenomenon that the paper becomes a parallelogram is largely related to the dimensional change amount of the paper upon water absorption. As an index indicating the dimensional change of paper at the time of water absorption, there is JAPAN, TAPPI No.27-78 “Paper and paperboard water immersion elongation test method A”, and the most water immersion of the paper measured by “Method A”. The direction in which the elongation was large was measured, and it was found that the smaller the immersion elongation in the direction of the largest immersion elongation, the smaller the parallelogramization of the paper.
[0015]
Therefore, the present inventors used a paper having a width of W and a length of 2 W that was left at 20 ° C. and 65% RH for 4 hours or more as an index representing the degree of parallelogram (P / M) of the paper. The sample is taken so that the length direction coincides with the paper making direction, folded in half at the center in the length direction of the paper, and left at 20 ° C. and 80% RH for 4 hours or more. (% /%) = {(ΔW / 2W) × 100} / (M ₂ −M ₁ )
ΔW: 20 ° C., 80% RH in the width direction misalignment length of the upper and lower papers M ₁ : Water content in paper at 20 ° C., 65% RH (%)
M ₂ : moisture in paper (%) at 20 ° C. and 80% RH
Is used, and the parallelogram degree (P / M) of this paper is 0.05 or less, particularly 0.03 or less when it is desired to improve color sharpness by reducing color misregistration. This was confirmed by numerous experiments.
[0016]
The degree of parallelogram formation of the paper can be adjusted by appropriately changing the freeness of the stock, the recirculation valve opening of the head box of the paper machine, and the jet wire ratio. The freeness of the stock affects the degree of flooding, and generally the freeness of the stock is high. In other words, the degree of freezing is lower when the beating is not progressing. The recirculation valve opening of the paper machine head box affects the fiber orientation angle, and the jet wire ratio of the paper machine affects the fiber orientation angle and the water immersion elongation.
Therefore, the absolute value is largest and the direction parallel to four sides of the paper that water elongation value is 5% or less of 6 degrees or less及beauty paper water elongation of the fiber orientation of the paper with respect to machine direction in the present invention It was also confirmed by a number of experiments that this is a necessary condition for the degree of shape (P / M) to be 0.05 or less.
[0017]
EXAMPLES Next, although an Example demonstrates this invention further in full detail, this invention is not limited by this.
With respect to newsprint paper for a multicolor lithographic printing press, the parallelogram formation degree, fiber orientation angle, water immersion elongation value, and image line deviation were measured by the following methods.
[0018]
(Parallelization degree)
FIG. 1 is an explanatory diagram showing the state before measuring the degree of parallelogram formation of the paper, and FIG. 2 is a case where the paper in the state shown in FIG. 1 is left at 20 ° C. and 80% RH for 4 hours or more. FIG. 3 is an explanatory diagram showing another example of the state when the paper in the state shown in FIG. 1 is left at 20 ° C. and 80% RH for 4 hours or more.
Previously not a 2 0 ° C., allowed to stand paper 4 hours or more under 65% R.H.. Humidity control environment, the size of the length in the machine direction 2W (1000 mm), the paper width direction to the width W (500 mm) Sampling is performed, and a sample in which the 500 mm × 500 mm square is folded in two at the center in the longitudinal direction of the paper is created as shown in FIG. The 20 ° C., at 65% R.H.. Paper and moisture testing methods paperboard paper in water samples after leaving the paper for 4 hours or more (M1) JIS P8127- ₁₉₇₉ described under humidity environment taking measurement.
Next, after moving this sample to a high humidity environment of 20 ° C. and 80% RH and leaving it for 4 hours or more, the deviation length in the width direction of the paper above and below the sample in the state of FIG. 2 or FIG. Measure ΔW. The 20 ° C., in 80% R.H. high humidity of the sample after leaving the paper for 4 hours or more under environmental paper in water. (M ₂₎ of JIS P8127- ₁₉₇₉ paper and moisture testing method paperboard according To measure.
Thereafter, the parallelogram degree (P / M) of the paper is obtained from the above measured values by the following formula.
P / M (% /%) = {(ΔW / 2W) × 100} / (M ₂ −M ₁ )
ΔW: 20 ° C., 80% RH in the width direction misalignment length of the upper and lower papers M ₁ : Water content in paper at 20 ° C., 65% RH (%)
M ₂ : moisture in paper (%) at 20 ° C. and 80% RH
[0019]
(Fiber orientation angle)
Measure the tensile rupture strength with a sample length (span length) of 0 mm in the tensile test at intervals of 5 degrees up to 175 degrees clockwise with the papermaking direction as 0 degrees, and calculate the measured values using the following formula: To obtain the fiber orientation angle α.
Z (θ) = C [1 + ηcos2 (θ−α)]
Here, Z (θ) is a tensile breaking strength at a measurement angle θ of paper, C is an average value of tensile breaking strength, α is a fiber orientation angle, and η is a fiber orientation index. The fiber orientation angle α can also be obtained by measuring the orientation angle of the molecular chain axis using a molecular orientation meter (trade name: MOA-2001A type) manufactured by Oji Paper Co., Ltd.
[0020]
(Α direction water immersion elongation)
The water immersion elongation is an index representing the dimensional change amount of paper at the time of water absorption, and can be measured by JAPAN, TAPPI No. 27-78 “Method of testing water and paperboard water elongation elongation method A”. In the direction of the largest immersion elongation value, the measurement of the immersion elongation is performed at intervals of 5 degrees up to 175 degrees clockwise with the papermaking direction being 0 degrees, and the obtained measured value is calculated using the following equation.
Y (θ) = K [1 + ηcos2 (θ−α)]
Here, Y (θ) is the immersion elongation value at the measurement angle θ of the paper, K is the average value of the immersion elongation, α is the direction of the largest immersion elongation, and η is the immersion elongation anisotropy index. .
[0021]
(Drawing misalignment)
Newspaper paper examples and comparative examples were evaluated using newspaper-type tower offset rotary presses (trade name: Color Top 6000, manufactured by Tokyo Kikai Seisakusho Co., Ltd.). A newsprint roll of A winding was used, the number of copies was 120,000 copies / hour, and printing was performed in the order of black, indigo, red, and yellow. The ink used and the fountain solution conditions were constant.
Image line misalignment is evaluated from the position of the registration marks of the first and fourth colors after the upper surface of the winding is pasted from the F-up product to the W-up product, 0.1 mm or less is ◎, and 0.2 mm or less ○, those exceeding 0.2 mm were evaluated as x.
[0022]
【Example】
(Newspaper production method)
After mixing and disaggregating 35 parts by weight of DIP (deinked pulp), 20 parts by weight of TMP (thermomechanical pulp), 20 parts by weight of GP (ground pulp) and 15 parts by weight of NBKP (conifer kraft pulp), the beaten mixed pulp is velvet After forming with a former II type paper machine at a paper making speed of 1000 m / min, drying with a pre-dryer, a starch-based coating solution was applied with 0.7 g / m ² using a gate roll size press, and an afterwriter After drying again, calendering was performed to produce newsprint with a basis weight of 43 g / m ² .
The manufactured jumbo winder was wound into a 50-roller A-roller for newspaper printing using a winder. Here, the winding was performed at the same winding position in the machine width direction, and two types of the upper surface of the winding, that is, an F-plane up product and a W-plane up product were created for color misalignment evaluation.
[0023]
Reference Examples 1-3, Comparative Examples 1-3
Using 160ml stock of freeness (Canadian standard freeness), fixing the jet wire ratio (J / W ratio) to 99%, and adjusting the recirculation valve opening of the head box (Mitsubishi Heavy Industries' Convert Flow Head Box) Newspaper papers with different fiber orientation angles were manufactured by changing.
These treatment of the water elongation and streaked shift parallelogram degree (P / M) and fiber orientation angle and α direction of the newsprint was measured, a flat row four sides formulated degree as shown in Table 1 If it was 0.05 or less, the line deviation was good.
[0024]
[Table 1]

[0025]
Reference Examples 4-5, Comparative Examples 4-5
Newspapers with different fiber orientation angles and different degrees of water immersion in the α direction were produced by fixing the recirculation valve opening to 30% and the J / W ratio to 99%, and changing the freeness of the stock.
These treatment of the water elongation and streaked shift parallelogram degree (P / M) and fiber orientation angle and α direction of the newsprint was measured, a flat row four sides formulated degree as shown in Table 2 If it was 0.05 or less, the line deviation was good.
[0026]
[Table 2]

[0027]
Examples 1-2, Comparative Examples 6-8
Newspaper papers having different fiber orientation angles and different degrees of water immersion in the α direction were produced by using a stock having a freeness of 160 ml, fixing the recirculation valve opening degree to 30%, and changing the J / W ratio.
After measuring the parallelogram (P / M), the fiber orientation angle, the water immersion elongation in the α direction, and the image misalignment of each newspaper, the fiber orientation of the paper relative to the paper making direction as shown in Table 3 largest direction of the water elongation value of the absolute value of 6 degrees or less及beauty paper water elongation corner is 5% or less, a line shift is good if and parallelogram degree is 0.05 or less there were.
[0028]
[Table 3]

[0029]
【The invention's effect】
As described in detail above, the newsprint for multicolor printing press of the present invention has a small degree of parallelogram formation at the time of water absorption, and therefore the image after paster when a multicolor printing press is used for printing newsprint. The deviation of the line can be remarkably improved, and its industrial value is very large.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a state before measuring the degree of parallelogram formation of paper.
FIG. 2 is an explanatory diagram showing an example of a state where the paper in the state shown in FIG. 1 is left at 20 ° C. and 80% RH for 4 hours or more.
FIG. 3 is an explanatory diagram showing another example of the state in which the paper in the state shown in FIG. 1 is left at 20 ° C. and 80% RH for 4 hours or more.
[Explanation of symbols]
Width of sample taken from paper left at W 20 ° C, 65% RH for 4 hours or longer so that its length direction matches the paper making direction 2W Left at 20 ° C, 65% RH for 4 hours or longer Length in the papermaking direction of the sample collected so that its length direction matches the papermaking direction. ΔW 20 ° C, 80% RH.

Claims (1)

Largest direction of the water elongation value of the absolute value of 6 degrees or less及beauty paper water elongation of the fiber orientation of the paper with respect to machine direction is 5% or less, and 20 ℃, 65% R.H. 4 A paper having a width of W and a length of 2 W, which has been left for more than an hour, was collected so that the length direction coincided with the paper making direction, folded in half at the center in the length direction of the paper, and 20 ° C., 80% R.D. Newspaper paper for a multicolor lithographic rotary printing press, wherein the degree of parallelogram formation (P / M) of the paper obtained by the following formula when left in H. for 4 hours or more is 0.05 or less.
P / M (% /%) = {(ΔW / 2W) × 100} / (M ₂ −M ₁ )
ΔW: 20 ° C., 80% RH in the width direction misalignment length of the upper and lower papers M ₁ : Water content in paper at 20 ° C., 65% RH (%)
M ₂ : moisture in paper (%) at 20 ° C. and 80% RH

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