JP2000271851A - Nonworven fabric roller, and preliminary polishing method and device for metal plate for printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form no polishing line in a preliminary polishing and prevent inferior sand dressing in the polishing by setting the mean grain size contained in a nonwoven fabric to a prescribed value or less and the maximum grain size to a prescribed value or less and setting the density of the abrasive in the fiber surface of the nonwoven fabric to a prescribed value or more. SOLUTION: A nonwoven fabric roller 14 is so formed that a cylindrical core member 24 is fitted and fixed around a rotary shaft 22, a cylindrical nonwoven fabric 26 is fitted and fixed around the circumference of the core member 24, and the rotary shaft 22 is connected to a motor whose rotation speed is adjustable. Various kinds of nonwoven fabrics can be used for the nonwoven fabric 26 of the nonwoven fabric roller 14, for example, materials such as polyamide, polyester, nylon, rayon, etc., can be used. Abrasive contained in the nonwoven fabric is so constituted as having the mean grain size 50 μm or less, the maximum grain size 60 μm or less, and the density of the abrasive in the fiber surface of the nonwoven fabric is set to 60% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pre-polishing a nonwoven fabric roller and a metal plate for a printing plate. The present invention relates to a pre-polishing method and apparatus used.

[0002]

2. Description of the Related Art A web-shaped metal plate for a printing plate, for example, a thin plate of an aluminum plate or an aluminum alloy plate is polished to form fine irregularities called "grain" to roughen the printing plate. The printability of metal sheets for use. At present, a general polishing method for roughening a metal plate for a printing plate includes mechanical polishing using a roller-like brush (for example, Japanese Patent Publication No. 500047/1985).
Publication), electrochemical polishing for performing electrolysis in an electrolytic solution, or chemical polishing for immersing in a chemical.

However, a metal plate for a printing plate such as an aluminum plate having a locally concave portion is subjected to mechanical polishing, electrochemical polishing,
Further, when the chemical polishing is performed, there is a problem that the surface of the concave portion cannot be uniformly roughened, and the printing performance of the portion deteriorates. As a measure to solve such a problem, the present applicant has proposed that before the main polishing, the surface of the running printing plate metal plate is pre-ground with a nonwoven fabric roller containing an abrasive.

[0004]

However, when the metal plate for a printing plate is pre-polished with a conventional nonwoven fabric roller, it is possible to prevent poor graining during the main polishing. There was a defect that appearance failure (polishing streaks), which might be caused by the agent, occurred on the surface of the metal plate for a printing plate.

The present invention has been made in view of such circumstances, and it is an object of the present invention to prevent polishing streaks from being generated on the surface of a metal plate for a printing plate during preliminary polishing and to prevent poor graining during main polishing. It is an object of the present invention to provide a non-woven fabric roller and a pre-polishing method and apparatus for a metal plate for a printing plate which can be performed.

[0006]

According to the present invention, there is provided a non-woven fabric roller in which an abrasive is contained in a roll-shaped non-woven fabric, wherein an average particle diameter of the abrasive contained in the non-woven fabric is 50 μm or less. And the maximum particle size is 6
0 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric is 60% or more.

[0007] In order to achieve the above object, the present invention provides a pretreatment for polishing and roughening a metal plate for printing plate by applying a polishing agent to the surface of a running web-shaped metal plate for printing. In the pre-polishing method for a printing plate metal plate, which is pre-ground with a non-woven fabric roller containing, the average particle size of the abrasive contained in the non-woven fabric is at least 50 μm or less and the maximum particle size at least before the start of using the non-woven fabric roller Is 60 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric is 60% or more.

Further, in order to achieve the above object, the present invention pre-polishes the surface of a running web-shaped metal plate for printing as a pretreatment for final polishing and roughening the metal plate for a printing plate. In the pre-polishing device for a printing plate metal plate, the average particle size of the abrasive contained in the roll-shaped nonwoven fabric is arranged on one side of the printing plate metal plate, and the maximum particle size is 50 μm or less. 60 μm or less, and a nonwoven fabric roller in which the density of the abrasive is 60% or more on the fiber surface of the nonwoven fabric, and a pair of the nonwoven fabric rollers are arranged at a predetermined interval on the other side of the printing plate metal plate, A support roller for supporting the printing plate metal plate, an advancing / retracting device for pressing the nonwoven fabric roller toward the support roller and pushing the printing plate metal plate between the pair of support rollers, and the printing plate metal plate Water on the surface of And a water supply device.

According to the present invention, the average particle size of the abrasive contained in the roll-shaped nonwoven fabric is 50 μm or less, the maximum particle size is 60 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric is 60% or more. The metal plate for the printing plate is pre-ground using a non-woven fabric roller, so that no polishing streaks are generated on the surface of the metal plate for the printing plate during the pre-polishing, and the graining is poor during the main polishing. Can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a non-woven fabric roller and a pre-polishing method and apparatus for a metal plate for a printing plate according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 is a configuration diagram of an apparatus for pre-polishing a metal plate for a printing plate according to the present invention. The preliminary polishing device 10 mainly includes a nonwoven fabric roller 14 disposed on one side of the printing plate metal plate 12.
And a pair of support rollers 16, 16 arranged on the other side to support the printing plate metal plate 12, and a non-woven fabric roller 14 pressed against the support roller 16 to move the printing plate metal plate 12 to a pair of non-woven fabric rollers And a water supply device 20 for supplying water to the surface of the printing plate metal plate 12.

The non-woven fabric roller 14 has a cylindrical core member 24 fitted and fixed to the rotating shaft 22, and a cylindrical non-woven fabric 26 fitted and fixed to the peripheral surface of the core member 24, and the rotating speed of the rotating shaft 22 can be adjusted. Motor (not shown). As the nonwoven fabric 26 of the nonwoven fabric roller 14, various nonwoven fabrics can be used. For example, polyamide, polyester,
A material such as nylon or rayon can be used, and a material having a surface hardness of 20 degrees or more in the state of the nonwoven fabric roller 14 is preferable. The non-woven fabric 26 of the non-woven fabric roller 14 contains an abrasive. As the abrasive, for example, fine sand, silica sand, alumina powder, silicon carbide, or the like can be used.

The abrasive contained in the nonwoven fabric of the nonwoven fabric roller has an average particle size of 50 μm or less, a maximum particle size of 60 μm or less, and a density of the abrasive on the fiber surface of the nonwoven fabric of 60% or more. Is configured to be In this case, as long as the average particle diameter has a function as an abrasive, the finer the finer the particle size, the better the finer the particle size is 50 μm or less. In addition, as long as the maximum particle size has a function as an abrasive, the finer the particle size, the finer the better if it is 60 μm or less. The density of the abrasive may be 60% or more, but in consideration of the removal of the abrasive in the preliminary polishing, + 10%
It is preferable to set the density so as to have a margin of at least%.

The measurement of the average particle diameter and the maximum particle diameter is performed by immersing 10 cm ³ of non-woven fabric fibers of a non-woven fabric roller in a solvent to dissolve the binder to which the abrasive is fixed, and to collect only the abrasive. This was performed by measuring with a particle size distribution meter. The density of the abrasive was determined by calculating the fixed density of the abrasive per fixed surface area of the nonwoven fiber after photographing the nonwoven fiber with a scanning microscope at 150 times in three visual fields.

In order to obtain an abrasive satisfying this particle size, the abrasive material is pulverized with a pulverizer and subjected to a flotation method, a stretching separation method, or the like to measure the average particle size to 5 μm using the average particle size as a scale.
Classify into multiple particle groups by unit. Then, a first selection is first made to select a particle group satisfying the condition that the average particle diameter is 50 μm or less from the classified particle groups. Similarly, classification is performed to prepare a plurality of particle groups having an average particle diameter of 50 μm or less. Next, a second selection of selecting a particle group satisfying the condition that the maximum particle diameter is 60 μm or less from the particle group satisfying the condition that the average particle diameter is 50 μm or less is now performed by using the maximum particle diameter as a scale. Do. Finally, the particles that have passed the first and second selections are gathered together to obtain a sufficient amount of abrasive to be included in the nonwoven fabric of the nonwoven roller.

The thus obtained abrasive having an average particle diameter of 50 μm or less and a maximum particle diameter of 60 μm or less is contained in the nonwoven fabric so that the density of the abrasive on the fiber surface of the nonwoven fabric becomes 60% or more. For example, a dipping method can be employed as a method for containing the dip. That is, the abrasive obtained by the classification is dispersed in a phenol solution of styrene-butadiene rubber (binder), and the nonwoven fabric roller is rotated at a constant speed while the nonwoven fabric of the nonwoven fabric roller is partially immersed in the abrasive dispersion. I do. Thereby, the abrasive dispersion is evenly impregnated into the nonwoven fabric. Next, the nonwoven fabric roller impregnated with the abrasive dispersion is dried to remove the phenol solution. Thereby, the abrasive is fixed to the fiber surface of the nonwoven fabric by the binder. At this time, the density of the abrasive on the fiber surface of the nonwoven fabric becomes 60% or more while performing trial and error such as adjusting the rotation speed of the nonwoven fabric roller or scraping off excess abrasive dispersion with a squeeze roller after impregnation. To do. The method for obtaining the abrasive according to the present invention is not limited to the classification and dipping methods described above, but may be any method that can satisfy the conditions of the average particle diameter, the maximum particle diameter, and the density.

The nonwoven fabric roller 14 containing the abrasive as described above is moved by the advance / retreat device 18 in the direction of the arrow AB in the direction of 100.
mm so that it can be pushed back and forth between a pair of support rollers 16 described later. The preliminary polishing amount is adjusted by controlling the polishing pressure by changing the pushing amount. Further, by pressing the nonwoven fabric roller 14 between the pair of support rollers 16 via the printing plate metal plate 12, preliminary polishing can be performed in a state where the nonwoven fabric roller 14 is in surface contact with the printing plate metal plate 12. .

A pair of support rollers 16 for supporting the printing plate metal plate 12 are formed by fitting a cylindrical hard rubber or metal cylinder to a rotating shaft 28. The distance (L) between the pair of support rollers 16 is the same as that of the nonwoven fabric roller 1.
4 are arranged to be shorter than the diameter (D). The pair of support rollers 16 rotate at the same speed as the traveling speed of the printing plate metal plate 12. And the nonwoven fabric roller 14
The nonwoven fabric roller 14 is pressed between the pair of support rollers 16 via the printing plate metal plate 12, and is polished in a state where the nonwoven fabric roller 14 is in surface contact with the surface of the printing plate metal plate 12.

A pair of water supply devices 20 are arranged upstream and downstream of the nonwoven fabric roller 14 in the running direction of the printing plate metal plate 12. Water can be supplied to the surface by directly supplying water to the running printing plate metal plate 12 or by supplying water to the nonwoven fabric roller 14 to indirectly supply water to the surface. Since there are some, the nonwoven fabric roller 14
Water supply is easier to manage.

According to the pre-polishing apparatus configured as described above, the average particle diameter of the abrasive contained in the roll-shaped nonwoven fabric is 50 μm or less, the maximum particle diameter is 60 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric. The metal plate for a printing plate is preliminarily polished using a nonwoven fabric roller having a ratio of not less than 60%, so that no polishing streaks due to the abrasive are generated on the surface of the metal plate for a printing plate in the pre-polishing, and Poor graining property at the time of main polishing can be prevented.

In this case, the numerical value of the average particle diameter and the maximum particle diameter of the abrasive contained in the nonwoven fabric and the numerical value of the density of the abrasive on the fiber surface of the nonwoven fabric may be at least numerical values before the use of the nonwoven fabric roller. It is even better if the value is maintained after use. In particular, since the density may decrease due to the abrasive falling off due to polishing or the like, it is preferable that the density be set to a value that has a margin of + 10% or more as compared with the case where the value is barely 60%.

[0021]

[Embodiment] Using the pre-polishing apparatus described in the embodiment,
The test results obtained by performing preliminary polishing using an aluminum plate as a metal plate for a printing plate will be described below. As for the aluminum plate, a printing aluminum coil having a thickness of 0.24 mm and a width of 100 mm was unwound from the unwinding device, inserted between the nonwoven fabric roller and the support roller, and wound up by the winding device.

The nonwoven fabric roller has a diameter of 300 mm and a width of 15 mm.
A non-woven fabric of 0 mm was used, and silicon carbide was contained in the nonwoven fabric as an abrasive. The conditions of the average particle diameter, the maximum particle diameter, and the density of the abrasive on the fiber surface of the nonwoven fabric are as shown in Table 1. That is, among the test plots, Examples 1 to 4 were pre-polished using a nonwoven fabric roller formed so as to satisfy all the conditions for containing the abrasive according to the present invention, and Comparative Examples 1 to 3 corresponded to the present invention. A nonwoven fabric roller formed so as not to satisfy the condition for containing the abrasive was used.

The pair of support rollers use rubber rollers having a diameter of 200 mm and a width of 150 mm, and are arranged so that the distance between the pair of support rollers is smaller than the diameter of the nonwoven fabric roller. It rotates at the speed. In addition, water was sprayed on the surface of the aluminum plate by a water supply device, and a nonwoven fabric roller was pushed between support rolls by an advancing / retracting device, so that the polishing pressure was +2 A
/ 100 mm.

As described above, Examples 1 to 4 and Comparative Examples 1 to 4 in which only the conditions for the abrasive contained in the nonwoven fabric roller were changed.
The surface of the aluminum plate was preliminarily polished by the nonwoven fabric roller of each test section of No. 3, and the state of occurrence of polishing streaks at that time was visually inspected. The evaluation of the polishing streak was as follows.
△: almost none, △: a little, △ ×: many, ×
... An extremely large five-level evaluation was given, and a score of △ or higher was considered acceptable.

[0025]

[Table 1] (Note) The “average particle diameter”, “maximum particle diameter” and “density” in Table 1 are the average particle diameter and maximum particle diameter of the abrasive contained in the nonwoven fabric of the nonwoven fabric roller, and the abrasive on the fiber surface of the nonwoven fabric. Is the density of

As can be seen from the evaluation results of the polishing streak in Table 1, in Examples 1 to 4, the nonwoven fabric roller formed so as to satisfy all the conditions for containing the abrasive according to the present invention was used. Good results were obtained with little or no development. The "density" was measured 5 hours after the continuous polishing, and the same value as the "density" before starting the use of the nonwoven fabric roller could be maintained.

On the other hand, in Comparative Examples 1 to 3, any one of “average particle diameter”, “maximum particle diameter” and “density” was set so as to be out of the condition for containing the abrasive according to the present invention. Polishing streaks caused by particles in the agent occurred. In particular, in the case of Comparative Example 3 in which all of the “average particle diameter”, “maximum particle diameter”, and “density” were out of the conditions, extremely large polishing streaks were generated.

When comparing Example 4 with Comparative Example 1, Comparative Example 1 satisfies the conditions of “average particle diameter” and “maximum particle diameter”,
Although the “density” slightly deviates from the condition, a large number of polishing streaks are generated, which is a bad result, and it is expected that the “density” greatly affects the generation of the polishing streaks. However, looking at Comparative Example 2, even if the conditions of "density" and "average particle size" are satisfied, the "maximum particle size" slightly deviates from the condition, and many polishing streaks are generated, resulting in a bad result. From this, it can be seen that one of the "average particle diameter", "maximum particle diameter" and "density" does not have a particularly large influence on the generation of polishing streaks,
As in the present invention, it is necessary to satisfy all the conditions of “average particle diameter”, “maximum particle diameter”, and “density”.

[0029]

As described above, according to the non-woven fabric roller and the pre-polishing method and apparatus of the printing plate metal plate according to the present invention, in the pre-polishing, the surface of the printing plate metal plate is caused by abrasive particles. It is possible to prevent or suppress the generation of polishing streaks, and to prevent poor graining property during the main polishing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus for pre-polishing a metal plate for a printing plate of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Pre-grinding device, 12 ... Metal plate for printing plates, 13 ... Advance / retreat device, 14 ... Non-woven fabric roller, 16 ... Support roller, 18
... Advancing / retreating device, 20 ... Water supply device, 26 ... Non-woven fabric

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA00 AB01 AB03 DA18 EA01 2H114 AA11 FA06 GA03 3C058 AA09 AA12 AB03 AB06 AC04 CA01 CB02 CB10

Claims (3)

[Claims] 1. A nonwoven fabric roller in which an abrasive is contained in a roll-shaped nonwoven fabric, wherein the abrasive contained in the nonwoven fabric has an average particle diameter of 50 μm.
And the maximum particle diameter is 60 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric is 6 μm or less.
A nonwoven fabric roller having a content of 0% or more. 2. A printing plate in which the surface of a running web-shaped printing plate metal plate is pre-ground by a nonwoven fabric roller containing an abrasive as a pretreatment for main polishing and roughening the printing plate metal plate. In the method for pre-polishing a metal plate for use, the average particle diameter of the abrasive contained in the non-woven fabric at least before the start of using the non-woven fabric roller is 50 μm or less, the maximum particle diameter is 60 μm or less, and the fibers of the non-woven fabric The density of the abrasive on the surface is 60%
A pre-polishing method for a metal plate for a printing plate characterized by the above. 3. A pre-polishing device for a printing plate metal plate for pre-polishing the surface of a running web-shaped printing plate metal plate as a pretreatment for main polishing and roughening the printing plate metal plate, The average particle diameter of the abrasive disposed on one side of the printing plate metal plate and contained in the roll-shaped nonwoven fabric is 50 μm.
And the maximum particle diameter is 60 μm or less, and the density of the abrasive on the fiber surface of the nonwoven fabric is 6 μm or less.
A non-woven fabric roller that is 0% or more, a pair of support rollers that are arranged at a predetermined interval on the other side of the printing plate metal plate and that support the printing plate metal plate, A reciprocating device that presses against the roller side to push the printing plate metal plate between the pair of support rollers; and a water supply device that supplies water to the surface of the printing plate metal plate. Pre-grinding device for plate metal plate.