JP2001328368A - Blanket for printing press and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tubular blanket for printing which will not generate separation between a surface layer and an inside foamed layer upon printing. SOLUTION: The manufacturing method for the tubular blanket 1, having the process of laminating sequentially a hard rubber layer, an inextensible layer and a compressive surface rubber layer 7 on the outside of a sleeve 2, is characterized in the forming process of the compressive surface of a compressive porous area 7b having mutually independent voids and a surface rubber area having no effective void wherein foaming agent is mixed into the compressive surface rubber layer 7 to foam and form voids along the whole area in thickness as an initial condition and, thereafter, the voids in a part near the outer peripheral surface 7a of the surface rubber area are blasted to generate the inflow of surrounding rubber material into the voids to form a layer having continuously different densities in the thickness direction of the compressive surface rubber layer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tubular blanket for a printing press and a method for producing the same.
The present invention relates to a tubular blanket to be mounted on the outer peripheral surface of a blanket cylinder in a printing press and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as a blanket cylinder installed in a commercial offset printing machine or the like, a printing machine in which a sleeve-shaped outer cylinder (cylindrical blanket) is mounted on the outer peripheral surface of a base roller 10 has been put into practical use, and has become common. ing. This blanket is formed into a seamless tubular shape so that the non-printing length in the web advancing direction is greatly reduced, so that the waste paper can be reduced and there is no seam and the vibration caused by the seam when the printing cylinder is pressed and rotated. Since printing is no longer performed, printing can be performed at a higher speed, and the productivity can be greatly improved.

A typical example of a conventional cylindrical blanket 13 has a structure illustrated in FIGS. 5 and 6, and a layer structure is configured as shown in FIG. As shown in FIG. 7, the tubular blanket is basically composed of multiple layers, the sleeve 2 is usually a metal such as nickel, 3 is an intermediate rubber layer (hard rubber layer), and 4 is a non-stretchable layer. 5 is a compressible layer, 6 is a surface rubber layer. In the cylindrical blanket 13 illustrated in these figures, the hard rubber layer 3, the non-stretchable layer 4, and the compressible layer are provided between the surface rubber layer 6 constituting the outer peripheral surface and the sleeve 2 constituting the inner peripheral surface from the inside. 5 are sequentially laminated. As an example, the compressible layer 5 employs a sponge layer such as foamed rubber, and the non-stretchable layer 4 employs a non-stretchable thread such as a cotton thread 9. The yarn 9 is wound in a coil shape along the circumference.

[0004] Each laminated material will be described.
And the hard rubber layer 3 are the base roller 1 of the blanket cylinder.
It has characteristics such as strength, rigidity, workability, and the like required for mounting on the blanket 0, and characteristics corresponding to the functions required for printing. The rubber layer 6 on the outer peripheral surface is made of a material having mechanical strength and having excellent solvent resistance to withstand swelling deterioration due to a solvent or the like. The non-stretchable layer 4 functions to maintain the strength and rigidity of the entire blanket. The compressible layer 5 has a role of giving a cushioning property. For example, the compressible layer is made of foamed rubber or the like. The blanket 13 receives ink from a printing plate wound around a plate cylinder and transfers a picture pattern onto a web. The configuration and function of the laminated material directly affect print quality. During printing, printing pressure is applied between the plate cylinder and the blanket, and the rubber layer of the blanket is compressed and deformed. In the case where there is no compressible layer made of a foamed base material or the like and only the surface rubber layer, the surface rubber layer swells on the contact surface with the plate cylinder, and it becomes difficult to smoothly feed. Providing the paper enables smooth paper feeding.

However, the conventional general blanket 13 has an extreme difference in hardness (stretchability) at the engaging portion between the compressible layer 5 and the surface rubber layer 6, which makes it difficult to stick each other. When the printing pressure is applied to the blanket, there is a problem that the layers are easily separated. For this bonding, a thermosetting adhesive is usually used, and about 5/1
It was manufactured by a process of applying and drying to a thickness of about 00 mm. Further, since the surface rubber layer 6 is repeatedly compressed and sheared during the printing operation, there is a problem that a shear force is generated at the boundary with the compressible layer 5 and the layer is easily peeled off.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present inventors have proposed a layer having a solvent resistance which is smooth and smooth on the surface, and having a foamed layer which compresses when a printing pressure is applied inside. In order to develop a tubular printing blanket in which these layers do not cause separation between layers during printing, intensive studies have been made. As a result, the present inventors unified the foamed layer having the voids and the surface rubber layer to form no boundary,
It has been found that the foamed portion is gradually reduced to form a single-layered compressible surface rubber layer, and separation is prevented by eliminating a clear boundary line, thereby solving the above problem. The present invention has been completed from such a viewpoint.

[0007]

That is, the present invention relates to a method for producing a cylindrical blanket, comprising a step of sequentially laminating a hard rubber layer, a non-stretchable layer and a compressible surface rubber layer on the outside of a sleeve. In the step of forming the compressible surface rubber layer into a compressible porous region having voids independent of each other and a surface rubber region having no effective voids, a foaming agent is mixed into the compressible surface rubber layer and foamed. After forming a void portion in the entire thickness direction as an initial state, the void portion near the outer peripheral surface of the surface rubber region is ruptured to allow the surrounding rubber material to flow, and the thickness of the compressible surface rubber layer is reduced. An object of the present invention is to provide a blanket manufacturing method for a printing press in which layers having different densities are formed steplessly in the direction. Here, a foaming agent such as an NBR material can be used for the compressible surface rubber layer, and among the bubbles formed over the entire region in the thickness direction as an initial state, a portion near the outer peripheral surface is formed. In the process in which the bubbles burst and the surrounding rubber material flows into the air space, a so-called integral skin method can be suitably used.

The present invention also relates to a method for producing a tubular blanket comprising a step of sequentially laminating a hard rubber layer, a non-stretchable layer and a compressible surface rubber layer on the outside of a sleeve. In the step of forming a compressible porous region having independent voids and a surface rubber region having no effective voids, after mixing a foaming agent into the compressible surface rubber layer, the inside of the compressible porous region By heating the peripheral surface, the surrounding foaming agent is foamed (foaming reaction) to generate voids, and by cooling the outer peripheral surface of the surface rubber region, no voids are generated. An object of the present invention is to provide a method for manufacturing a blanket for a printing press, which forms layers having different densities in a stepless manner in the thickness direction of a surface rubber layer. Here, in the step of foaming the compressible surface rubber layer using a predetermined foaming agent, a foaming reaction is promoted in a high-temperature region, but the property that the foaming reaction is delayed or does not occur in a low-temperature region is utilized. By cooling the surface region and heating the inner surface region side, a predetermined temperature difference is intentionally adjusted and set in the thickness direction to form a compressible porous region and a surface rubber region.

Further, the present invention provides a tubular printing press blanket having a structure in which a hard rubber layer, a non-stretchable layer, a compressible surface rubber layer and the like are sequentially laminated on the outside of a sleeve. Is formed by a compressible porous region having voids independent of each other, and a surface rubber region having no effective voids, and for a printing press in which the density changes in the thickness direction of the compressible surface rubber layer due to the voids. Offer blankets. Here, in the printing blanket of the present invention, a mode in which the amount of voids is continuously reduced from the compressible porous region to the surface rubber region is preferably exemplified. If the method of the present invention as described above is used, the surface is a layer having a solvent resistance that is smooth and smooth, and has a foamed layer that compresses when printing pressure is applied inside, and peeling between layers during printing is prevented. A tubular printing blanket that does not occur can be manufactured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. Embodiment (Part 1) FIG. 1 is an overall schematic configuration diagram of a tubular blanket for a printing press according to the present invention, and FIG. 2 is a configuration diagram (partial sectional view) of a laminated material forming the tubular blanket. It is. The tubular blanket 1 for a printing press according to the present embodiment is configured as shown in FIGS. The tubular blanket 1 of the present embodiment has an intermediate rubber layer (hard rubber layer) 3 outside the sleeve 2 and a non-stretchable layer 4 around which a cotton thread 9 or the like is wound, for example. Further, a compressible surface rubber layer 7 which has compressibility due to voids 8 and has a smooth surface is further laminated thereon.

The compressible surface rubber layer 7 includes a compressible porous region 7b having voids (bubbles) 8 on the inner side in the thickness direction of the rubber layer (on the side of the non-stretchable layer 4) and a thickness direction of the layer. It is formed by a surface rubber region 7a where no effective void (bubble) 8 exists on the outside (surface side). In addition, the compressible surface rubber layer 7 in the present invention is provided in the respective regions (7
a, 7b) do not have a clear boundary physically and chemically from each other, and the difference is only the presence or absence of the void 8 (the distribution amount of bubbles) effective for vibration compression absorption. That is, the surface layer 7a has a predetermined hardness required for the surface rubber layer of the blanket, and has a characteristic of having a moderate cushioning property by the elastic function of the inner side 7b. .

By the way, in the present embodiment, as the method for producing the compressible surface rubber layer 7 according to the present invention, the above-mentioned rubber layer 7 is formed by adding a foaming agent to an unvulcanized compound, Simultaneously foam. Then, bubbles are formed over the entire area in the thickness direction as an initial state. Next, the bubble 8 in the portion 7a near the surface of the formed bubble 8 ruptures, and the rubber material (NBR material or the like) flows into the ruptured air space (phenomenon) by using the property (phenomenon) in the thickness direction. In this method, layers having different densities (bubble distribution amounts) are formed steplessly. This manufacturing method applies a so-called integral skin method in manufacturing a compressible surface rubber layer. Here, the amount of the foaming agent to be used is appropriately determined and is not particularly limited. Usually, about 8 to 10 g of a foaming agent is added to 100 g of the rubber material to cause foaming.

The tubular blanket 1 for a printing press according to the present embodiment is constructed as described above. The sleeve 2 and the intermediate rubber layer (hard rubber layer) 3 are mounted on the base roller 10 of the blanket cylinder. It has characteristics such as necessary strength, rigidity, workability, and the like, as well as characteristics corresponding to functions required for printing, and is a base material of the tubular blanket 1. The intermediate rubber layer (hard rubber layer) 3, the non-stretchable layer 4, and the compressible surface rubber layer 7 function to adjust the compression characteristics, shear characteristics, and the like of the blanket 1 to predetermined characteristics. The compressible surface rubber layer 7 on the outer peripheral surface can withstand swelling and deterioration due to a solvent or the like, and has a predetermined hardness in the surface region so as to have mechanical strength, and the inside of the sleeve in the radial direction is reduced in rigidity by bubbles. , To have a predetermined elasticity. Therefore, as the elastomer constituting the compressible surface rubber layer, those excellent in oil resistance are suitably used, and specific examples thereof include various synthetic rubbers and thermoplastic elastomers. It is preferable to use an elastomer which has an excellent effect of absorbing the vibration and has a high damping property against vibration. Specific examples of such an elastomer include, for example, synthetic rubber such as acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber, and urethane rubber. The blanket 1 having such a surface rubber layer receives ink from a printing plate in an upstream process and transfers a pattern onto a web as described above.
The structure and function of the laminated material are the most important factors in print quality, and in particular, the compressible surface rubber layer 7 is directly related to print quality.

An example of a manufacturing process of a blanket for a printing press is as follows. The printing blanket of the present invention is a blanket having a laminated structure formed in a tubular shape. First, a Ni-based sleeve is subjected to a process of providing an adhesive layer as a pre-adhesion process, and a base rubber layer (intermediate layer) is formed thereon. The rubber layer 3) is molded. Next, a layer (the non-stretchable layer 4) around which the yarn is wound after forming the adhesive layer is formed.
Furthermore, after providing an adhesive layer thereon, the compressible surface rubber layer 7 is formed. In the step of forming each adhesive layer, a drying step is included, if necessary, as appropriate.

The tubular blanket 1 of the present invention is constructed as described above. (1) Since the step of independently forming the compressible porous layer can be omitted, waste materials (for example, sulfide) generated in the manufacturing process can be omitted. (2) The conventional surface rubber layer 6 and the compressible surface rubber layer 7 corresponding to the compressible layer 5 are repeatedly compressed during the printing operation. Even with shear deformation, there is no boundary line, durability against peeling due to shearing force is increased, and as a result, product life can be extended,
And various other effects can be obtained.

Embodiment (No. 2) FIG. 3 is an explanatory view showing an example of a manufacturing method for processing and forming a cylindrical blanket according to the present invention, and FIG. 4 shows the structure of a compressible surface rubber layer 7. FIG. The tubular blanket 1 of the present embodiment has a hard rubber layer 3, a non-stretchable layer 4, and a compressible surface rubber layer 7 laminated on the outside of a sleeve 2 as in the first embodiment (first embodiment). The compressible surface rubber layer 7 has a compressible porous region 7b having voids 8 independent of each other inside the layer (the non-stretchable layer 4 side) and an effective void 8 outside the layer (surface side). No surface rubber area 7
It is composed of a part. Then, the same function as that of the above-described embodiment (No. 1) can be obtained.

The present embodiment is different from the first embodiment only in the method of producing the compressible surface rubber layer 7. This method will be described below. In the present embodiment, as in the first embodiment, a foaming agent is used to form a void as a bubble portion. In the foaming step, the temperature difference is deliberately set in the thickness direction to control the rate of generation of bubbles to form layers having different densities in the thickness direction. As shown in FIG.
As for the material to be foamed, the surface side of 7a (the side used for the outer periphery) is set to a low temperature, and the surface side of 7b (the side used for the inner periphery) is set to a high temperature.
At this time, the surface used on the outer peripheral side needs to be a smooth surface that is not foamed. In other words, the foaming reaction is accelerated in the high-temperature region, but on the other hand, the foaming reaction is slow or does not occur in the low-temperature region. The feature is that the region 7b and the surface rubber region 7a are formed.

As an example of a manufacturing apparatus for carrying out the manufacturing method of the present invention, a heater 11 as a heating means is provided inside the cylindrical sleeve 1 as shown in an example in FIG. An air pump and an air nozzle 12 are arranged, and the heating and cooling temperatures can be set arbitrarily. Here, the amount of the foaming agent to be used is appropriately determined in the same manner as in Embodiment (Part 1), and is not particularly limited.
About 8 to 10 g of a foaming agent is added to 0 g for foaming. The temperature range when such an amount of the foaming agent is used can be arbitrarily set. For example, it is manufactured at about 140 ° C. or less on the low-temperature side which is the outer circumference, and about 160 ° C. or more on the high-temperature side which is the inner circumference. Is preferred. In the example of FIG. 3, the outer frame 14 is provided at a position away from the outer diameter of the tubular blanket 1, and a structure in which cool air is blown from the air nozzle 12 of the outer frame 14 is shown. The outer frame 14 may be contacted with the outer peripheral surface of the outer frame 14 without providing the nozzles 12 and the cooling medium may be passed through. As the cooling medium, cooling water or the like can be used in addition to the cooling gas.

The method of manufacturing the tubular bracket 1 for a printing press according to the present embodiment is performed as described above. The tubular blanket 1 has the following advantages in addition to the same effects as those of the first embodiment. effective. (3) Since the temperature inside and outside the rubber layer in the radial direction can be mechanically controlled in the process of forming the compressible surface rubber layer 7, the structure of the compressible surface rubber layer 7, that is, the thickness direction of the rubber foam layer, Can be set arbitrarily. (4) In setting mechanical characteristics (compression characteristics and shear characteristics), the degree of freedom in design is large and performance can be improved. That is, by adjusting the distance and ratio of 7a and 7b in the compressible surface rubber layer 7, the paper feed amount when printing on paper is changed, and the paper feed amount that can be sent in one rotation can be adjusted. In the case of continuous paper feed, the degree of tension varies depending on the type and thickness of the paper, and if the tension is too high, the paper tears, etc., so it is possible to adjust the paper feed amount regardless of the paper. Is preferable because it can be controlled stably. As described above, by adjusting the ratio in the rubber layer 7, it is possible to manufacture a blanket capable of feeding an amount suitable for the paper.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made without departing from the gist of the present invention. What you get.

[0021]

According to the present invention, the step of independently forming a compressible porous layer can be omitted, so that waste materials generated in the manufacturing process can be reduced, and the influence on the environment can be reduced. is there. In addition, even if the blanket is repeatedly compressed and sheared during the printing operation, there is no boundary line in the compressible surface rubber layer of the blanket, and the durability against peeling due to shearing force is increased, and as a result, the product life can be extended. In the process of forming the compressible surface rubber layer, since the temperature inside and outside the rubber layer in the radial direction can be mechanically controlled, the degree of foaming in the thickness direction of the compressible surface rubber layer 7 can be arbitrarily set. Can be. Further, according to the cylindrical blanket of the present invention, the degree of freedom in design is large in setting the mechanical characteristics, and the performance can be improved.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of a tubular blanket for a printing press according to the present invention.

FIG. 2 is a diagram showing in detail a layer configuration of a portion A in FIG. 1, and is a configuration diagram (partial sectional view) of a laminated material forming a tubular blanket.

FIG. 3 is an explanatory view showing an example of a manufacturing method for processing and forming a printing tubular blanket according to the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a compressible surface rubber layer of the present invention.

FIG. 5 is a configuration diagram of a general tubular blanket, and is a perspective view showing an overall schematic structure.

FIG. 6 is a view showing a cross section taken along a line P-P in FIG. 5, and is a configuration diagram (cross-sectional view) of a laminated material forming a tubular blanket.

7 is a diagram showing a layer configuration of a portion B in FIG. 5, and is a configuration diagram (partial sectional view) of a laminated material forming a tubular blanket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical blanket 2 Sleeve 3 Intermediate rubber layer (hard rubber layer) 4 Non-stretchable layer 5 Compressible layer 6 Surface rubber layer 7 Compressible surface rubber layer 8 Void (bubble) 9 Cotton thread 10 Main shaft roller 11 Heating means 12 Cooling means 13 blanket 14 outer frame

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H114 CA02 CA03 CA04 CA10 DA46 DA71 EA08 4F074 AA05 AA12 AA14 AA78 BA00 CC04Y CC61 DA19 DA54 4F213 AA20E AA31 AA45 AD10 AD12 AG03 AG08 WA03 WA15 WA43 WA53 WA87 WB01 WB10 WB22 WF02 WF06 WF21 WF37 WK03 WK05 WW01 WW06 WW23 WW33

Claims (4)

[Claims] 1. A method for manufacturing a cylindrical blanket, comprising a step of sequentially laminating a hard rubber layer, a non-stretchable layer, and a compressible surface rubber layer on the outside of a sleeve. In the step of forming a compressible porous region and a surface rubber region having no effective voids, a foaming agent is mixed into the compressible surface rubber layer and foamed,
After forming a void portion in the entire thickness direction as an initial state, the void portion near the outer peripheral surface of the surface rubber region is ruptured to allow the surrounding rubber material to flow, and the thickness direction of the compressible surface rubber layer is increased. The method for producing a blanket for a printing press according to any one of claims 1 to 3, wherein layers having different densities are formed steplessly. 2. A method for producing a tubular blanket comprising a step of sequentially laminating a hard rubber layer, a non-stretchable layer and a compressible surface rubber layer on the outside of a sleeve. In the step of forming a compressible porous region and a surface rubber region having no effective voids, after mixing a foaming agent into the compressible surface rubber layer, the inner peripheral surface of the compressible porous region is heated. By causing the surrounding foaming agent to undergo a foaming reaction to generate voids, and by cooling the outer peripheral surface of the surface rubber region, the temperature difference is adjusted, whereby the density of the compressible surface rubber layer is steplessly increased in the thickness direction. A method for producing a blanket for a printing press, characterized in that different layers are formed. 3. A blanket for a printing press having a structure in which a hard rubber layer, a non-stretchable layer, a compressible surface rubber layer, and the like are sequentially laminated on the outside of a sleeve, wherein the compressible surface rubber layers are independent of each other. A printing machine comprising a compressible porous region having voids and a surface rubber region having no effective voids, wherein the density changes in the thickness direction of the compressible surface rubber layer due to the voids. Blanket. 4. The blanket for a printing press according to claim 3, wherein the amount of voids in the compressible surface rubber layer decreases steplessly from the compressible porous region to the surface rubber region.