JP2000263960A - Method for preliminary grinding of metal sheet for printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an unevenness of a preliminary grinding from being generated on the surface of a metal sheet for printing plate in a preliminary grinding, and also, prevent an unfavorable grinding from being generated at the time of a main grinding. SOLUTION: A preliminary grinding is performed by setting the rotating peripheral velocity V1 (m/min) of a non-woven fabric roller the running speed V2 (m/min) of a metal sheet for printing plate, the average particle diameter D (μm) of an abrasive contained in the non-woven fabric roller in terms of equivalent circle diameter, and a preliminary grinding amount X (μm) for the metal sheet for printing plate in a manner to satisfy the formula 5<=D×V1×X/V2<=20000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for pre-polishing a metal plate for a printing plate, and more particularly to a method for pre-polishing a running web-shaped metal plate for a printing plate with a nonwoven fabric roller.

[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 the surface of a running printing plate metal plate be pre-ground with a nonwoven fabric roller before the main polishing.

[0004]

However, in the conventional pre-polishing method, pre-polishing unevenness occurs on the surface of the printing plate metal plate subjected to pre-polishing, or segregation occurs on the surface layer of the printing plate metal plate. There is a disadvantage that impurities such as Cu and Fe remain and graining failure occurs in the main polishing in a later step.

The present invention has been made in view of such circumstances, and does not cause pre-polishing unevenness on the surface of a metal plate for a printing plate in pre-polishing, and also prevents poor graining during main polishing. It is an object of the present invention to provide a pre-polishing method for a printing plate metal plate that can be performed.

[0006]

According to the present invention, in order to achieve the above object, as a pretreatment for polishing and roughening a printing plate metal plate, the surface of a running web-shaped printing plate metal plate is treated. In a pre-polishing method of a metal plate for a printing plate, which is pre-ground with a non-woven fabric roller containing an abrasive, wherein the peripheral speed of rotation of the non-woven fabric roller is V ₁ (m / min), V ₂ (m / min), and the average particle size when the abrasive contained in the nonwoven fabric roller is represented by an equivalent circle diameter is D (μ).
m), when the pre-polishing amount of the printing plate metal plate is X (μm), the V ₁ , V ₂ , and D are set so as to satisfy the following expression: 5 ≦ D × V ₁ × X / V ₂ ≦ 20,000 , X are set and preliminary polishing is performed.

According to the present invention, 5 ≦ D × V ₁ × X / V ₂
In order to satisfy the equation of ≤ 20,000, the rotational peripheral speed V ₁ (m / min) of the nonwoven fabric roller and the traveling speed V of the printing plate metal plate
₂ (m / min), pre-polishing by setting the average particle diameter D (μm) when the abrasive contained in the nonwoven fabric roller is represented by a circle-equivalent diameter, and the preliminary polishing amount X (μm) of the printing plate metal plate As a result, unevenness in preliminary polishing does not occur, and poor graining property during main polishing can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for pre-polishing 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 an overall configuration diagram of a pre-polishing apparatus to which a pre-polishing method for a printing plate metal plate according to the present invention is applied.

The pre-polishing device 10 mainly includes a nonwoven fabric roller 14 disposed on one side of the metal plate 12 for a printing plate.
A pair of support rollers 16, 16 arranged on the other side to support the printing plate metal plate 12, an advance / retreat device 18 for adjusting the amount of pre-polishing, and a variable winding speed of the winding device 30 for printing. Traveling speed adjusting means for adjusting the traveling speed of the plate metal plate 12, and a water supply device 2 for supplying water to the surface of the printing plate metal plate 12;
0.

In the nonwoven fabric roller 14, a cylindrical core member 24 is fitted and fixed to the rotating shaft 22, and a cylindrical nonwoven fabric 26 is fitted and fixed to the peripheral surface of the core member 24. The rotating speed of the rotating shaft 22 is adjustable. Motor 32. As the nonwoven fabric 26 of the nonwoven fabric roller 14, various nonwoven fabrics can be used. For example, a material such as polyamide, polyester, nylon, or rayon can be used. It is preferable that the degree is higher than the degree. This nonwoven fabric 26 has an average particle size of 1 to 100.
An abrasive of μm is contained, and examples of the abrasive include gold sand, silica sand, alumina powder, and silicon carbide.

The non-woven fabric roller 14 is provided with an advance / retreat device 18.
Thereby, it can be advanced and retracted about 100 mm in the direction of arrow AB, and can be pushed between a pair of support rollers 16 described later. The pre-polishing amount is adjusted by changing the pushing amount and controlling the polishing pressure. Further, by pressing the nonwoven fabric roller 14 between the pair of support rollers 16 via the printing plate metal plate 12, pre-polishing can be performed in a state where the nonwoven fabric roller is in surface contact with the printing plate metal plate.

A pair of support rollers 16 for supporting the printing plate metal plate 12 are configured by fitting a cylindrical hard rubber or metal cylinder to the rotating shaft 28 and fixing the same. The distance (L) between the pair of support rollers 16 is shorter than the diameter (D) of the nonwoven fabric roller 14. The pair of support rollers 16 are used for the printing plate metal plate 12.
It rotates at the same speed as the running speed. Then, the nonwoven fabric roller 14 is pressed between the pair of support rollers 16 via the printing plate metal plate 12, and 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 on the upstream and downstream sides 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.

The metal plate 12 for a printing plate is guided from an unwinding device (not shown), inserted between the nonwoven fabric roller 14 and the support rollers 16, 16, and then connected to a winding device 30. You. Then, the winding device 30 winds the printing plate metal plate 12 so that the printing plate metal plate travels, and the winding speed of the winding device 30 is varied, thereby forming the printing plate metal plate 12. Adjust the running speed.

A method of performing pre-polishing using the pre-polishing apparatus for a metal plate for a printing plate configured as described above will be described. The pre-polishing method of the present invention may be arranged such that 5 ≦ D × V ₁ × X / V ₂ ≦ 20
000 (hereinafter referred to as “pre-polishing condition formula”), the rotational peripheral speed V ₁ (m / m
Min), the traveling speed V _{2 of} the printing plate metal plate 12 (m / min),
Pre-polishing is performed by setting an average particle diameter D (μm) when the abrasive contained in the nonwoven fabric roller 14 is represented by a circle equivalent diameter and a preliminary polishing amount X (μm) of the printing plate metal plate 12. That is, the rotational speed V ₁ of the nonwoven fabric roller 14 varies the rotation speed of the motor 32, and the traveling speed V ₂ of the printing plate metal plate 12 varies by varying the winding speed of the winding device 30, thereby performing preliminary polishing. The amount X is determined by varying the amount of pushing of the advance / retreat device 18. The average particle diameter D when the abrasive is represented by the equivalent circle diameter is previously contained in the nonwoven fabric 26 within the range of 1 to 100 μm.

In this case, V₁, V_Two, D and X
Alternatively, the pre-polishing condition may be satisfied, but there are many variables.
Too complicated. Therefore, V₁, V_Two, D and X
That is, D and X are fixed, and at this time, the pre-polishing conditional expression
V to satisfy₁And V _TwoTo change (control)
Can also. Furthermore, V₁, V_Two, D and X, D,
X, V_TwoIs fixed, and the pre-polishing condition is satisfied at this time.
V to add₁Can be changed (controlled).

According to the present invention, the rotational peripheral speed V ₁ (m / min) of the nonwoven fabric roller is set so as to satisfy the pre-polishing condition.
The traveling speed V ₂ (m / min) of the printing plate metal plate, the average particle diameter D (μm) when the abrasive contained in the nonwoven fabric roller is represented by a circle-equivalent diameter, and the preliminary polishing amount X of the printing plate metal plate Since the pre-polishing is performed by setting (μm), it is possible to perform the pre-polishing of uniform surface quality without causing the pre-polishing unevenness on the surface of the printing plate metal plate. Further, if pre-polishing that satisfies the pre-polishing conditional expression is performed, impurities such as Cu and Fe segregated on the surface layer of the printing plate metal plate 12 do not remain. This can prevent poor graining property from occurring.

[0018]

[Embodiment] Using the pre-polishing apparatus described in the embodiment,
The test results obtained by performing the preliminary polishing method of the present invention 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. A nonwoven fabric roller having a diameter of 300 mm and a width of 150 mm was used, and as an abrasive to be contained in the nonwoven fabric, silicon carbide having an average particle diameter of 7 μm as represented by a circle equivalent diameter was used. As the supporting roller, a pair of rubber rollers having a diameter of 200 mm was arranged at a separation distance smaller than the diameter of the nonwoven fabric roller, and rotated at the same speed as the traveling speed of the aluminum plate. And the polishing pressure is +3 A /
The nonwoven fabric roller was pressed against the aluminum plate by an advance / retreat device so as to be 100 mm, and the amount of preliminary polishing was set.

Then, the rotational peripheral speed V of the nonwoven fabric roller
₁ (m / min) and the traveling speed V ₂ (m / min
) Was changed and the state of occurrence of preliminary polishing unevenness and the state of graining in the main polishing were visually observed. Examples 1 to 5 in Table 1 are the cases where V ₁ and V ₂ were changed so as to satisfy the pre-polishing conditions, and Comparative Examples 1 to 4 were such that V ₁ and V ₂ did not satisfy the pre-polishing conditions. This is the case when it has been changed.

The pre-polishing unevenness was evaluated on a five-point scale:…: none, △: almost none, △: a little, 多 く: many, X: extremely many.
…: Good, △: slightly good, Δ: slightly poor, Δ ×: poor, ×: extremely poor. Then, both the preliminary polishing unevenness and the graining property were evaluated as “Good” or more.

[0021]

[Table 1] As can be seen from the results in Table 1, in the case of Examples 1 to 5 satisfying the pre-polishing conditions, there was almost no pre-polishing unevenness and good graining performance. In particular, when the numerical values in the pre-polishing conditions are 1300 and 12,500,
There was no preliminary polishing unevenness, and the graining property was good. From this, 1300 ≦ D × V ₁ × X / V
It is considered that satisfying ₂ ≦ 12500 gives better results.

On the other hand, in the case of Comparative Examples 1 to 4, which did not satisfy the pre-polishing condition formula, the pre-polishing unevenness was large and the graining property was poor. In particular, in Comparative Examples 1 and 2 in which the numerical value in the pre-polishing condition expression was less than 5, the graining property was in a range of poor to extremely poor, which was not good.

[0023]

As described above, according to the method for pre-polishing a metal plate for a printing plate according to the present invention, there is no uneven pre-polishing on the surface of the metal plate for a printing plate during pre-polishing, and In this case, poor graining property can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a pre-polishing apparatus to which a pre-polishing method for a metal plate for a printing plate of the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Pre-polishing apparatus, 12 ... Metal plate for printing plates, 14 ... Nonwoven fabric roller, 16 ... Support roller, 18 ... Advance / retreat apparatus, 20
... water supply device, 25 ... motor, 26 ... non-woven fabric, 30 ... winding device

 ──────────────────────────────────────────────────の Continued on front page F term (reference) 2H025 AA00 AB01 DA18 EA01 2H096 AA00 AA01 AA07 CA01 CA03 2H114 AA04 EA02 FA01 GA03 3C049 AA06 AA07 AA09 AB04 AC04 BA04 BB09 CA01 CA04 CB01 CB10 3C0 A04 A04 A04 A04 A04 A04 CB01 CB10

Claims (3)

[Claims] 1. A printing plate in which the surface of a running web-shaped printing plate metal plate is pre-ground with a nonwoven fabric roller containing an abrasive as a pretreatment for main polishing and roughening the printing plate metal plate. In the method of pre-polishing the metal plate for polishing, the rotational peripheral speed of the nonwoven fabric roller is V ₁ (m / min), the traveling speed of the metal plate for printing plate is V ₂ (m / min), When the average particle diameter when the agent is represented by a circle-equivalent diameter is D (μm) and the preliminary polishing amount of the printing plate metal plate is X (μm), the following formula: 5 ≦ D × V ₁ × X / V A pre-polishing method for a metal plate for a printing plate, wherein V ₁ , V ₂ , D, and X are set so as to satisfy ₂ ≦ 20,000 and pre-polishing is performed. 2. The method according to claim 2, wherein₁, V_Two, D, and X, D and X
5 × D × V₁× X / V _Two≤ 20,000
V to add₁And V_Two, Characterized by changing
The method for pre-polishing a metal plate for a printing plate according to claim 1. Wherein said V _1, V _2, D, of X, said fixing the D and X and _{V 2 5 ≦ D × V 1} × X / V 2 ≦ 2000
2. The pre-polishing method for a metal plate for a printing plate according to claim ₁ , wherein V1 is changed so as to satisfy 0.