JPH04331152A - Method of fixing printing plate and sheet for the same - Google Patents

Abstract

PURPOSE:To exhaust a mixed gas, and to fix a printing plate to a printing drum through a pressure-sensitive adhesive layer without air bubbles under the layer. CONSTITUTION:A printing plate is fixed in such a manner that a fixing sheet (2) having pressure-sensitive adhesive layers having irregular structure on both surfaces of a support base material and the exhaust path of air is formed and the printing plate (1) is bonded with a printing drum (4) through the fixing sheet (2) or the printing plate and a carrier film are bonded and the carrier film is mounted on the printing drum. Accordingly, printing pressure is equalized on the basis of the excellent cushioning properties of the fixing sheet, and the generation of defective printing such as printing unevenness, blurring, bleeding, etc., is prevented, thus attaining accurate superior printing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a printing plate and a fixing sheet therefor, which allows entrained gas to be naturally exhausted and is suitable for flexographic printing.

0002

[Prior Art] Conventionally, as a method for fixing a printing plate to a printing drum in flexo printing, etc., there has been a method of adhering the printing plate to the printing drum via a flat adhesive layer made of a double-sided adhesive sheet, or a method of fixing the printing plate to the printing drum by flattening the printing plate. It was known to adhere to a carrier film via an adhesive layer and attach it to a printing drum. However, there was a problem in that gases mixed in when adhering the printing plate to the adhesive layer formed gas pockets and deformed the printing plate, resulting in printing defects such as printing unevenness, fading, and bleeding.

0003

SUMMARY OF THE INVENTION An object of the present invention is to develop a method for fixing a printing plate and a fixing sheet thereof, which can naturally exhaust gases mixed in when a printing plate is adhered to an adhesive layer.

0004

[Means for Solving the Problems] The present invention provides a method for fixing a printing plate, which is characterized by adhering a printing plate to a printing drum via a fixing sheet having an adhesive layer with an uneven structure on both sides of a supporting base material. It provides:

[0005] The present invention also provides a printing method characterized in that a printing plate and a carrier film are adhered to each other via a fixing sheet having an adhesive layer having a concavo-convex structure on both sides of a supporting base material, and the carrier film is attached to a printing drum. This provides a method for fixing plates.

Furthermore, the present invention provides a fixing sheet for use in the above-mentioned fixing method, which is characterized by having an adhesive layer with a concavo-convex structure on both sides of the supporting base material and having an exhaust path for mixed gas. .

[0007]

[Operation] By adhering the printing plate to the printing drum or carrier film via the fixing sheet that has an uneven adhesive layer on both sides of the supporting base material, mixed gas is naturally exhausted from the gaps between the uneven adhesive layers. , the occurrence of gas accumulation is prevented.

[0008]

Embodiment FIGS. 1 and 2 illustrate the fixing state according to the present invention. 1 is a printing plate, 2 is a fixed sheet, 3 is a carrier film, and 4 is a printing drum. Furthermore, fixed sheets are illustrated in FIGS. 3 and 4. 21 and 23 are adhesive layers having an uneven structure, and 22 is a supporting base material.

As illustrated in FIG. 1, one of the fixing methods of the present invention is to adhere a printing plate 1 to a printing drum 4 via a fixing sheet 2 having an uneven adhesive layer on both sides of a supporting base material. It is. The sequence of operations may be such that the printing plate is adhered to the fixed sheet and then adhered to the printing drum, or may be such that the fixed sheet is adhered to the printing drum and the printing plate is adhered to it.

Another fixing method of the present invention, as exemplified in FIG. 2, involves bonding the printing plate 1 and the carrier film 3 via a fixing sheet 2 having an uneven adhesive layer on both sides of a supporting base material. It is attached to the printing drum 4.

[0011] The sequence of operations in the fixing method may be such that the printing plate is adhered to a fixing sheet and then adhered to the carrier film, or the fixing sheet is adhered to the carrier film and the printing plate is adhered to it. It may be a method. The carrier film to which the printing plate is fixed may be attached to the printing drum by any suitable method, such as a known method in which the end of the carrier film is held in a groove provided in the printing drum using a pressing tool.

The fixing sheet used in the fixing method of the present invention has an adhesive layer with an uneven structure on both sides of a supporting base material. An appropriate thin film may be used as the supporting base material. Generally, for example, films made of plastics such as polyester, polyethylene, polypropylene, and polyvinyl chloride, woven or nonwoven fabrics, foam sheets, metal foils, and the like are used. As the carrier film, those exemplified above are generally used.

[0013] The adhesive layer having an uneven structure on both sides of the supporting base material is designed to form an exhaust path for mixed gas. The structure may be arbitrary, such as a striped structure or a dotted structure. The formation of an adhesive layer with an uneven structure is carried out, for example, by pattern coating the adhesive, or by filling a mold corresponding to the uneven structure with the adhesive, molding it, and then transferring it to a supporting base material. be able to.

[0014] The height difference in the uneven structure of the adhesive layer may be determined as appropriate, but in general, it is
~500 μm. In addition, the gap between the convex portions, that is, the width of the concave portions, which serve as exhaust paths for mixed gas in the uneven structure may be determined as appropriate, but is generally set to 50 μm to 5 mm. The size of the convex portion that becomes the adhesive surface with the printing plate etc. is generally 1 to 100 mm based on the width or diameter, but is not limited to this.

[0015] As the adhesive, an appropriate adhesive may be used, such as a rubber adhesive, an acrylic adhesive, or an adhesive that loses its adhesive strength. Rather than enhancing the cushioning properties due to the uneven structure, it is preferable to use materials with excellent rubber elasticity.

The fixing method of the present invention is preferably applied to, for example, a flexographic printing method, in which a flexible printing plate made of a rubber plate or a resin plate is fixed to a printing drum, and printing is performed while the printing drum rotates. can.

Incidentally, acrylic adhesive was pattern-coated on both sides of a polyester film with a thickness of 80 μm through a mask, and the width was 5 mm, the thickness was 80 μm, and the gap was 0.5 to 1.
A fixing sheet was formed by providing a striped adhesive layer of mm in size, and the fixing sheet was adhered to a newspaper-sized resin plate, which was then adhesively fixed to a printing drum.

[0018] In the above case, no gas accumulation was observed, and printing was possible without causing printing defects such as printing unevenness, fading, and bleeding. In addition, 40 pieces of the above fixed sheet
The pressure required to compress % is 50kg/50x50m
It was m2. According to the above, the pressure required for 40% compression of a polyester film in which adhesive layers were provided on both surfaces was 160 kg/50 x 50 mm2. Therefore, in the case of the fixed sheet, 40% compression can be achieved with about ⅓ of the pressure, and the cushioning properties are excellent.

[0019]

According to the present invention, mixed gas can be exhausted and the printing plate can be fixed to the printing drum via the adhesive layer without gas accumulation. Further, the printing pressure is equalized based on the good cushioning properties of the fixed sheet, and printing defects such as printing unevenness, fading, and blurring are prevented from occurring, and accurate and good printing can be achieved.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view of a fixed state according to the present invention.

FIG. 2 is an explanatory sectional view of another fixed state according to the present invention.

FIG. 3 is a sectional view illustrating a fixed sheet.

FIG. 4 is a sectional view illustrating another fixing sheet.

[Explanation of symbols]

1: Print version 2: Fixed sheet 21, 23: Adhesive layer with uneven structure 22: Support base material 3: Carrier film 4: Printing drum

Claims (3)

[Claims] 1. A method for fixing a printing plate, comprising adhering the printing plate to a printing drum via a fixing sheet having an adhesive layer with an uneven structure on both sides of a supporting base material. 2. Fixing of a printing plate, characterized by adhering a printing plate and a carrier film via a fixing sheet having an adhesive layer with an uneven structure on both sides of a supporting base material, and attaching the carrier film to a printing drum. Method. 3. A fixing sheet for use in the fixing method according to claim 1 or 2, characterized in that the supporting base material has an adhesive layer with a concavo-convex structure on both sides and has an exhaust path for mixed gas.