JP2679475B2 - Method of manufacturing newsprint rolls - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method of manufacturing newsprint rolls used in a printing plant. More specifically, the present invention relates to a method for manufacturing a roll of newsprint that is less likely to cause tearing of the top paper of the roll even when the roll is conveyed by an impact force caused by collision between the rolls.

[Prior art]

In recent years, automation in printing plants has improved significantly in all respects. For example, in some newspaper printing factories, almost all operations from the loading of newsprint rolls into a paper warehouse to the unpacking of wrapping paper and the feeding of paper to a rotary press are almost completely automated. Each automated process is
It is common to judge whether a process is normal or abnormal by a sensor, and if it is abnormal, stop the process for safety and check it.

In the winding operation carried into the paper warehouse, the unwrapping is performed in advance to remove the wrapping paper, and it is often handled as it is, that is, in the form of the winding operation itself. Moreover, the printing speed of the printing machine is improved. There is an increasing demand for increasing the number of winding stations for the purpose of reducing the number of times of feeding to the rotary press, and as a result, the diameter of the winding becomes significantly large (larger diameter),
Along with this, the weight of the web is also increased, and a recent newsprint web has a 60-roll series, and the weight reaches about 1.2 tons.

FIG. 1 is a schematic diagram showing the flow of bare winding which has been unpacked and carried into a paper warehouse of a printing factory for printing newspaper. On the floor surface of a paper warehouse for such a newspaper printing factory, winding is usually provided with an inclination of 1 to 2 ° from the loading side to the unloading side. Is moved to a row with less winding, and is pushed out from the upper side of the inclined surface to the lower side, that is, from the carry-in side to the carry-out side by the moving pusher. It stops by colliding with the stopper provided in. continue,
The windings pushed out one after another collide with the previously stopped winding and are stopped. In this way, 4 to 5 windings are continuously placed in contact with each other at one place where one stopper is provided and are left standing. After that, these windings are sequentially sent out to a stopper provided below the unloading conveyor before the unloading surface, placed on the unloading conveyor depending on the unloading status of the winding, and sent to the rotary press. The same state as above is repeated at the place where this stopper is installed. The number of rows in the winding flow direction depends on the size of the printing plant.

[0005]

FIG.

[0006] In such a paper warehouse, the paper stopper on the winding and the impact generated by the collision with the winding may break several sheets of paper on the front side of the winding. This is because the paper strength of newsprint is weaker than that of other printing paper, and because the weight increases with the number of winding stations due to the reasons described above, the impact force is further promoted and the tearing occurs. The probability of occurrence is ever increasing.

[0007] Since the final end of the unwrapped unwrapped top paper is usually fixed with gum tape, adhesive tape, etc. When the tear spreads to the paper break, either the length corresponding to the outer circumference of the broken paper is left on the floor surface, or the paper is rolled up and rolled on the floor surface to reach the carry-out conveyor. Or, some of the top paper of the winding remains loosely wound around the winding and finally placed on the carry-out conveyor. At this time, the take-up detection sensor installed on the inclined surface is blocked by the broken pieces of paper and loose paper left on the floor surface, causing a trouble that the operation of the carry-out conveyor is stopped due to a malfunction, resulting in printing. The supply of the necessary winding is insufficient, and the printing process must be stopped. When such a stop trouble of the carry-out conveyor occurs, the operation of the process is temporarily stopped, and the worker must remove the broken paper piece, and the meaning of labor saving by automation is lost. . Moreover,
When such a problem occurs in a printing factory of a newspaper company for newspaper printing, where the demand for immediacy is extremely important, it is unacceptable because it may cause late delivery of the newspaper.

In order to solve such problems, various attempts have conventionally been made to improve the winding manufacturing method and the equipment. For example, in the improvement of the winding manufacturing method, (1) a method in which an adhesive tape is wound around the outer circumference of the winding to fix the final end of the winding upper paper to increase the sticking tension, (2) the paper itself A method of increasing the strength, (3) a method of changing the composition of the pulp fiber of the paper itself constituting the winding in order to mitigate the impact when the winding collides with the stopper or another winding and comes into contact therewith, etc. be able to. However, none of the methods and the combination thereof can completely eliminate the breakage at the time of collision of the winding.

On the other hand, in terms of equipment for transporting the winding, there is no scratch that may cause the tear of the upper paper of the winding, and an impact force is exerted when it collides with a winding stopper or another winding. The following attempts have been made for the purpose of alleviation. (1) A method of finishing the surface of the paper warehouse that is in contact with the winding such as a stopper installed on the floor surface or an inclined surface, painting or applying a Teflon sheet sufficiently so that there is no protruding portion, (2) Although a method of spraying a lubricant such as talc or baby powder on an inclined floor surface for the purpose of lowering the dynamic friction coefficient of the winding surface can be mentioned, but it has not been a fundamental solution. In particular, the method of spraying the lubricant on the floor surface is not preferable because the worker has to regularly spray the lubricant, which causes an increase in cost and a burden on the worker.

However, in a newly constructed printing factory, it is possible to minimize the inclination angle of the floor surface to be inclined to reduce the impact force generated by the collision caused by rolling rolling. In fact, there are many printing factories that are effective by combining these measures to prevent equipment breakage, but improvements in these facilities may only be possible within the overall layout of the printing plant. In many cases, it is not always possible to improve equipment, and problems such as equipment cost and construction period are involved, so this is not a satisfactory solution.

Looking at this problem from the standpoint of manufacturing newsprint, since the problem in terms of equipment belongs to the printing plant to the last, we would like to somehow handle it with a solution method for papermaking. Would be appropriate. Therefore, there has been a demand for the appearance of a roll of newsprint that is resistant to tearing even if the roll is handled in a paper warehouse with the current equipment of a printing factory.

[Problems to be solved by the invention]

In view of the above situation, the inventors of the present invention have eagerly studied the problems of the prior art by treating the problems of the prior art by kinematics, and as a result, added a friction coefficient increasing agent to the papermaking raw material to make the paper, and to produce JIS P81 between outer surfaces of another roll of paper
Assuming that the dynamic friction coefficient by 47 is μ ₁ and the dynamic friction coefficient between the papers (front side and back side) that make up the winding is μ ₂ , μ ₁ should be as small as possible and (μ ₂ −μ ₁ ) should be a certain value or more. The present invention has been completed by discovering that the winding of the paper having a value of μ ₂ equal to or higher than a certain level can prevent the tearing of the upper paper of the winding due to the collision of the windings during the transportation in the paper warehouse. Came to.

Accordingly, an object of the present invention is to wind up a newspaper in a printing factory having the present equipment, in which tearing of the unwrapped top paper is unlikely to occur while the unwrapped bare winder is conveyed. It is to provide a manufacturing method.

[Means for Solving the Problems]

The first aspect of the present invention is, in the production of newsprint paper for winding, papers which make up paper by internally adding a friction coefficient increasing agent to a papermaking raw material, and make up the paper after winding the newsprint paper. The dynamic friction coefficient μ ₂ according to JIS P 8147 of 0.
45 or more and 0.60 or less, and larger than the dynamic friction coefficient μ ₁ between the outer surfaces of the winding upper paper and another winding upper paper, and the difference (μ ₂ −μ ₁ ) is 0.14 or more. And a method for manufacturing a newspaper roll. A second aspect of the present invention is that the friction coefficient increasing agent has a particle ratio of 1 to 30 μm of at least 80% or more, and a particle ratio of 70 μm or more of 0.4% or less, and an average particle size of 5 to 10 μm. A method for producing a roll of newsprint according to the first aspect of the present invention, which is a filler composed of a hydrated silicate for papermaking and is added to a papermaking raw material in an amount of 0.2 to 3% by weight per absolutely dry pulp.

According to the present invention, as shown in FIG. 2, the winding A having a mass mKg is rotated at a speed vm by rolling on a slope having an inclination angle θ °.
It is assumed that a collision with the winding B, which is stationary at a speed of 1 / second, is performed. The momentum m × v of the winding A is expressed by the following equation, assuming that the winding A collides with B and receives the force of F and stands still after t seconds.

[0016]

[Formula 1] mv = Ft

[0017]

FIG. 2

It is clear that the larger the impact force F is, the larger the tearing of the top paper of the winding is, and in the formula (1), the weight m of the winding and the speed v at the time of collision are large as the factors. It is shown that F increases as it increases. In addition to the fact that the inclination angle θ of the slope is large as a factor for increasing the speed v, the rolling resistance (that is, the harder the winding is, the faster the speed v is
Becomes larger) and the coefficient of restitution (that is, the time t under which the force of F changes) changes intricately. Therefore, the force F generated when the windings collide due to pure kinematics or mechanics.
It is not easy to calculate However,
On the contrary, a rigorous calculation shows that the winding itself is not uniform, and the force F at the time of collision is significantly affected by a slight difference in the initial condition such as the initial speed when rolling the winding. Not practical.

On the other hand, if the force when a winding roll collides with another winding is set to a known value F ₀ , a frictional force is applied to the upper paper of the winding roll at the time of the collision, so this friction force and the tension of the paper. Examining the balance is a means of clarifying the phenomenon of tearing of the top paper of the roll.

As shown in FIG. 2, when the winding A rolls over and collides with the stationary winding B, the winding A,
It is assumed that the force of F ₀ is applied while both B are in contact with each other at point P.
At this time, the dynamic friction coefficient between the upper papers of winding A and B is μ
_When it is set to ₁ , a frictional force of μ ₁ F ₀ acts on the upper paper of the winding A, that is, a frictional force F _s (F _s = μ ₁ F ₀ ) is a force pulling in the circumferential direction on the upper paper of the winding. It becomes a load and becomes a driving force to break the top paper. Therefore, at this time, if the coefficient of kinetic friction between the papers that make up the winding is small, one upper paper will receive the force, but the upper paper will break only when the paper force of the paper is smaller than F _s. It is easy to do. However, if the dynamic friction coefficient between the papers that make up the take-up is large, the entire take-up behaves as if it were a single sheet of paper, so the frictional force generated during this collision is received by the whole take-up. , The probability that the top paper of the roll will tear will be extremely small.

Considering in this way, the condition that the top paper of the winding is not torn is that the sum of the paper force f _{p of the} newsprint for winding and the frictional force μ ₂ f inside the top paper of the winding is added. It is necessary to be larger than the frictional force of the outer surface (the surface of the winding) of the upper paper of the winding, and the formula 2 is satisfied.

[0022]

[Formula 2] f _p + μ ₂ f> μ ₁ f That is, f _p > f (μ ₁ −
μ ₂ )

Here, f: The force per unit width of the roll paper at the time of collision between the rolls f _p : Paper force per unit width of the roll newspaper paper μ ₁ : The upper paper roll Coefficient of dynamic friction between the outer surfaces μ ₂ : The coefficient of dynamic friction between the newspapers that make up the roll.

Equation 2 shows that the smaller the dynamic friction coefficient μ ₁ between the outer surfaces of the upper paper being wound, the less restrictive the paper force of the newsprint being wound (that is, the absolute value of the paper force is small. It is also good), and the larger the dynamic friction coefficient μ ₂ between the newspapers constituting the winding is, the more the paper force of the newspapers is not limited. The fact that reducing the coefficient of dynamic friction μ ₁ between the outer surfaces of the top paper of the winding is effective in preventing tearing is that talc is applied to the outer surface of the winding when handling bare winding in a paper warehouse of a printing factory. It is also clear from the fact that spraying a lubricant such as baby powder can effectively prevent tearing of the top paper of the roll.

However, in actual operation, the phenomenon is
It is very complicated, there is no way to know how much force the winding itself has at the time of collision, and the weight of the winding,
There is a considerable variation in the paper force and the coefficient of dynamic friction of the newspapers that make up the winding, and the difference in the coefficient of dynamic friction (μ ₁ −μ
_Since it is not perfect just because ₂ ) is small, in the present invention, (μ ₁ −μ ₂ ) is −0.25 or more −
It is in the range of 0.14 or less, that is, the difference (μ ₂ −
It is essential that the conditions are such that μ ₁ ) is 0.14 or more and 0.25 or less, and that the coefficient of dynamic friction μ ₂ between the newspapers constituting the winding is 0.45 or more and 0.60 or less. .

The coefficient of dynamic friction of paper depends on the kind of pulp used,
In the case of the present invention, depending on the filler, the surface property of the paper, etc.,
The upper limit of μ ₂ is about 0.60 even if the amount of the filler added internally is increased. On the other hand, the outer surface of the top paper of the winding is internally added with the friction coefficient increasing agent, so Although the ascending agent is exposed, it will come into contact with the ground, floor or other objects during transport of the winding to reduce the coefficient of friction. However, μ ₁ is limited to about 0.36 at most.

As a method of increasing the dynamic friction coefficient between the papers constituting the winding according to the present invention, a friction coefficient increasing agent is added to a papermaking raw material to perform papermaking in a known paper machine. In recent paper machines, the twin wire method is often used in paper machines to eliminate the difference between the front and back sides of the paper, but even the wire side is usually the first wire side (upper side).
Is usually the front surface, and the second wire surface (lower side) is the back surface. In the winding of newsprint, the second wire surface is wound so that the second wire surface is on the outside. In the present invention, the newsprint containing the friction coefficient increasing agent internally added is once wound on the jumbo reel and then cut into small diameters by the winder.

As the filler for internal addition as the friction coefficient increasing agent for the present invention, the proportion of particles having a particle size of 1 to 30 μm is at least 80% or more, and the proportion of particles of 70 μm or more is 0.4%. A hydrated silicate for papermaking having an average particle size of 0.05% or less, preferably in the range of 5 to 10 μm, is preferably used below, and is added to the papermaking raw material in the range of 0.2 to 3% by weight per bone-dry pulp. To be done. If the amount of the filler added exceeds 3% by weight, the effect of increasing the dynamic friction coefficient of the paper will not be significant, leading to an increase in cost, and the tensile strength, tear strength, burst strength, etc. of the resulting printing paper will also decrease. Therefore, it is not suitable for the present invention. Further, if the addition rate is less than 0.2% by weight, the dynamic friction coefficient of the paper suitable for the present invention cannot be obtained, which is not suitable.

The pulp raw materials used in the newsprint of the present invention include bleached softwood kraft pulp (NBKP), bleached hardwood pulp (LBKP), thermomechanical pulp (TMP), ground pulp (GP) deinked waste paper pulp (DIP). And the like, and these may be used in appropriate combination as desired. In the papermaking of the newsprint of the present invention, a paper strengthening agent, a retention improver and other papermaking chemicals are used if necessary, and further, a machine calendar or a super calendar depending on the printability required after papermaking. It is possible to perform the smoothing process with, for example.

In the present invention, a friction coefficient increasing agent is added to newsprint by an internal addition method so that the dynamic friction coefficient μ ₂ of the papers constituting the winding is 0.45 or more and 0.60 or less, and the outer surfaces of the windings are The dynamic friction coefficient of μ ₁ and the difference (μ ₂
By setting −μ ₁ ) to 0.14 or more, it is possible to absorb the frictional force generated due to the collision between the windings during the transportation in the paper warehouse in the entire winding. The outer surface of the top paper can be prevented from being torn, and the roll paper can be transported smoothly inside the paper warehouse. In addition, the printed matter can be delivered smoothly.

[0031]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In Examples and Comparative Examples,% and parts mean% by weight and parts by weight.

Example 1 14 parts of softwood kraft pulp, 40 parts of thermomechanical pulp, 7 parts of ground pulp and 39 parts of deinked waste paper pulp (newspaper) were mixed and disintegrated, and a freeness of 110 ml C.I. S. F. The mixed pulp adjusted to (Canadian standard freeness) has a particle ratio of 1 to 30 μm of at least 80% and a particle ratio of 70 μm or more produced by the method described in JP-B-1-60183. Average particle size of 4% or less 5 to 10 μm
A hydrated silicate for papermaking was added as a filler at a ratio of 1% with respect to absolutely dry pulp to prepare a paper stock.

Then, using this stock, a Bellbeformer type II paper machine (manufactured by Mitsubishi Heavy Industries, Ltd.) was used to produce paper at a speed of 1000.
Papermaking at m / min, through machine calendar, basis weight 47g
/ M ² and tensile strength of 3.5 Kgf / 15 mm for producing a jumbo roll of newsprint paper, cutting it with a winder, and winding it for newspaper printing with a dynamic friction coefficient μ ₂ 0.52 of the paper constituting the roll ( A winding, 50 continuous windings, a winding weight of 1,025 Kg) were produced in 250 pieces.

These windings were used in a printing plant A having a paper warehouse having a slope length of 12 m and a floor slope angle of 1.5 °. There was no occurrence of tearing of the upper paper of the winding at the time of collision between the windings in the process of conveying the unwrapped naked winding in the paper warehouse. The coefficient of dynamic friction μ ₁ between the outer surfaces of the upper papers of these windings is 0.36, and the difference (μ ₂ −μ ₁ ) is 0.1.
It was 6.

The methods for measuring the coefficient of dynamic friction, freeness and tensile strength used in the present invention are as follows. (1) Dynamic friction coefficient In accordance with the method of JIS P 8147, a horizontal digital friction coefficient measuring instrument (manufactured by Sagawa Seisakusho) was used to pull at a pulling speed of 2
It was measured at 00 mm / min. (2) Freeness The freeness was measured using a Canadian standard freeness tester specified in JIS P8121. (3) Tensile Strength The tensile strength was measured by an auto paper strength tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) according to the method specified in JIS P8113.

Comparative Example 1 The same as in Example 1 except that the hydrous silicate for papermaking was not added as a filler, the basis weight was 47 g / m ² , the tensile strength was 3.
Winding for newspaper printing (A winding, 50 mm, 5 Kgf / 15 mm, dynamic friction coefficient μ ₂ 0.41 between papers constituting winding)
260 pieces of continuous loading and winding weight of 1,025 Kg) were produced and used in the same printing factory A as in Example 1 under the same conditions. The tear of the upper paper of the winding at the time of collision between the windings in the process of transporting the winding in the paper warehouse occurred in the winding of 29 rolls, and the occurrence rate of the tear was 11%. . The coefficient of dynamic friction μ ₁ between the outer surfaces of the upper papers of these windings was 0.30, and (μ ₂ −μ ₁ ) was 0.11.

Example 2 13 parts of softwood kraft pulp, 33 parts of thermomechanical pulp, 12 parts of ground pulp, 42 of deinked waste paper pulp
Mix at a ratio of 1 part and disintegrate, and use a refiner to give a freeness of 105 ml C.I. S. F. Using mixed pulp adjusted to
The same paper wettable silicate as in Example 1 as a filler was added absolute dry weight of the pulp 2%, machine speed 1100 m / min and the other embodiments 1 same as to the basis weight of 47 g / m ^2, tensile strength 3. Winding for newspaper printing (A winding, 5 Kgf / 15 mm, dynamic friction coefficient μ ₂ 0.54 between papers constituting winding)
We manufacture 70 units of 45 continuous rolls and a winding weight of 923 kg.
The length of the inclined surface is 11 m and the inclination angle of the floor is 1.
Used in printing plant B, which has a 4 ° paper warehouse. There was no occurrence of tearing of the upper paper of the winding at the time of collision between the windings in the process of conveying the unwrapped naked winding in the paper warehouse. The coefficient of dynamic friction μ ₁ between the outer surfaces of the upper papers of these windings was 0.36 and (μ ₂ −μ ₁ ) was 0.18.

Comparative Example 2 13 parts of softwood kraft pulp, 37 parts of thermomechanical pulp, 16 parts of ground pulp, 36 deinked waste paper pulp
Mix at a ratio of 1 part and disintegrate, and use a refiner to give a freeness of 105 ml C.I. S. F. Using mixed pulp adjusted to
The basis weight was 47 g / m ² and the tensile strength was 3,6 in the same manner as in Example 1 except that the paper making speed was 1100 m / min without adding any filler.
Kgf / 15 mm, 100 rolls for newspaper printing (A roll, 45 rolls, weight 923 Kg for roll) with dynamic friction coefficient μ ₂ 0.41 between the papers that make up the roll were manufactured, and at printing plant B used. The tearing of the top paper of the winding at the time of collision between the windings in the process of conveying the unwrapped bare winding in the paper warehouse occurs in 10 windings. It was 10%. The coefficient of dynamic friction μ ₁ between the outer surfaces of the upper papers of these windings was 0.30, and (μ ₂ −μ ₁ ) was 0.11.

Example 3 9 parts of softwood kraft pulp, 4 thermomechanical pulp
3 parts, 13 parts of ground pulp, and 35 parts of deinked waste paper pulp are mixed and disintegrated, and the refiner gives a freeness of 10
0 ml C.I. S. F. Using the mixed pulp prepared as described above, the same hydrated silicate for papermaking as in Example 1 was added as a filler at a ratio of 1% and 2% based on the weight of the absolutely dry pulp, and separate paper materials were prepared. Then, using these stocks, a Bell Beformer III paper machine (manufactured by Mitsubishi Heavy Industries, Ltd.) was used to make paper at a paper making speed of 1100 m / min, and the paper was passed through a machine calendar to obtain a basis weight of 46 g / m ² and a tensile strength of 3.0 Kgf. /
15 mm and 3.1 Kgf / 15 mm, and the dynamic friction coefficient μ _{2 of} the paper constituting the winding is 0.48 and 0.
Fifty-two newspaper rolls for newspaper printing (A roll, 40 rolls, each weight of the roll was 820 kg) were produced.

These windings were rolled from the top of a test slope with a slope of 7.5 m and a floor slope of 1.9 °, which was created assuming the floor in the paper warehouse of the printing factory. By using a stopper installed at the lower end, the four rolls are lined up and the rolls are rolled, and the occurrence of tears on the roll top paper when the roll collides with another roll is checked. However, in each case, the top paper did not tear. Coefficients of dynamic friction μ ₁ between the outer surfaces of the rolled upper paper are 0.34 and 0.36, respectively (μ ₂ −
μ ₁ ) was 0.14 and 0.16, respectively.

Comparative Example 3 A paper having a basis weight of 46 g / m ² , a tensile strength of 3.0 Kgf / 15 mm, and a winding material was prepared in the same manner as in Example 3 except that hydrated silicate for papermaking was not added as a filler. Winding for newspaper printing with dynamic friction coefficient μ ₂ 0.40 (A winding, 40
50 pieces of continuous winding and winding weight of 820 kg) were manufactured. When the situation of occurrence of tears on the upper paper of the winder was examined in the same manner as in Example 3 for these winders, 25 of the 50 winders were torn, and this was the rate of occurrence of tears. Was 50%. The coefficient of dynamic friction μ ₁ between the outer surfaces of the upper papers of these windings was 0.29, and (μ ₂ −μ ₁ ) was 0.11.

The results obtained in Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1.

[0043]

[Table 1]

[0044]

Winding newsprint for removing the present invention exhibits dynamic friction coefficient of the paper that constitute the winding to be subjected to printing by paper making by adding the friction coefficient increasing agent in papermaking raw materials mu ₂ 0.45 it was 0.60 or less than, greater than the dynamic friction coefficient mu ₁ of the outer surface between the upper paper Ueshi and another winding of the winding, and the difference (μ ₂ -μ ₁₎ 0.14 or more This makes it possible to absorb the frictional force generated by the collision of the rolls during transport in the warehouse of the printing factory, and to prevent the top sheet of the rolls from tearing. Therefore, the winding operation can be smoothly carried out in the paper warehouse, so that the trouble of the temporary stop caused by the delay of the paper feeding in the printing process is solved, and the printing and the printed matter can be smoothly delivered. To be able to Achieve the results.

[Brief description of the drawings]

FIG. 1 is a schematic elevation view and a side view showing a flow of unwrapped roll-in paper carried in a paper warehouse of a printing factory for printing newspaper. 1. ... Transport port 2. ... Movement pusher 3. ... Conveyor 4. ... Rolling paper 5. ... Stopper 6. ... Movement stopper 7. ... Carry-out port (to rotary press) 8. ... Inclination angle, θ

[Fig. 2] Contact state of two rolls on a slope of a paper warehouse
It is a schematic side view which shows a state. 9. ... Winding A 10. ... Winding B 11. ... The winding A is rolling and is in contact with the winding B
Force applied during₀  12. ... Point of contact between winding A and B, P 13. ... The distance that winding A and B move after contact, S 14. ... Rolling movement direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Publication No. 1-1810 (JP, B2)

Claims (2)

(57) [Claims] 1. A method for producing a newsprint for winding up, wherein a friction coefficient increasing agent is internally added to a papermaking raw material for papermaking, and the newspaper is wound up.
The dynamic friction coefficient μ _{2 according} to 47 is 0.45 or more and 0.60 or less, and is larger than the dynamic friction coefficient μ ₁ between the outer surfaces of the winding upper paper and another winding upper paper, and the difference (μ _2- μ
₁ ) The value of 0.14 or more, a method for producing a roll of newsprint. 2. The friction coefficient increasing agent has a particle ratio in the range of 1 to 30 μm of at least 80% or more and 70 μm.
The above particle ratio is 0.4% or less and the average particle size is 5 to 10
2. A roll of newsprint according to claim 1, which is a filler composed of hydrated silicate for papermaking in the range of .mu.m, and is added to 0.2 to 3% by weight of absolutely dry pulp to a papermaking raw material. Method of manufacturing.