JP2000343853A - Printing blanket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a proper nerve and restorability by providing a surface rubber layer on one surface of a compressive layer formed of one type of double or multilayer fibers through an adhesive rubber layer, and providing a fiber cloth on the other surface through an adhesive rubber layer. SOLUTION: The printing blanket 1 comprises a surface rubber layer 4 on one surface of a compressive layer 2 through an adhesive layer 3a and a fiber cloth 5 on the other surface of the layer 2 through an adhesive rubber layer 3b. The layer 2 is a layer for giving restorability necessary to satisfactorily print the blanket 1, and constituted of at least one type of double or multilayer fibers. According to this constitution, a mounting work on a blanket cylinder is facilitated by a nerve given by the layer 2 having the layers 3a, 3b on both the surfaces. Simultaneously, good printing is performed by restorability given by the layer 2 and flatness of the layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing blanket, and more particularly to a printing blanket usable for a business form printing machine.

[0002]

2. Description of the Related Art Offset printing, which is one of printing methods, has been widely used as a method capable of high quality printing. In offset printing, dampening water and ink are generally supplied to a blanket cylinder equipped with a blanket, and then the ink on the blanket is transferred to the printing material supplied between the blanket cylinder and the impression cylinder, and printing is performed. Yes, the blanket plays a very important role. Therefore, it is necessary to use an optimal blanket according to the use, purpose, printing conditions, and the like of the printed matter.

[0003] On the other hand, business forms such as slips, continuous forms, output paper, etc. are often printed with ruled lines, solid portions, optically readable characters, etc., and are different from ordinary color prints. Printed using an offset printing press. The blanket used in this business form printing press has a stiffness (rigidity) for facilitating mounting work on the blanket cylinder, and restores to compression for good printing. It is required to be as thin as about 1 mm in order to be mounted on a blanket cylinder having a small cylinder diameter. In addition, it is naturally required that the surface rubber layer on which the printing ink supplied from the plate cylinder is applied is flat and the printability is good.

[0004]

The blanket is generally a laminated structure in which a surface rubber layer is formed on a compressible layer,
In order to impart the required properties to the blanket, for example, a blanket using a non-woven fabric in the compressible layer (Japanese Utility Model Application Laid-Open No. 63-30165), a blanket using a rubber sponge (Japanese Patent Application Laid-Open No. 235696/1990), etc. Is disclosed.

However, none of the conventional printing blankets used for business form printing machines have the above-mentioned stiffness (high rigidity), resilience, and excellent printability.

The present invention has been made in view of the above-mentioned circumstances, and has both a moderate waist strength (high rigidity) and a restoring property, and has excellent printing suitability in a business form printing press. An object of the present invention is to provide a printing blanket that can be developed.

[0007]

In order to achieve the above object, a printing blanket of the present invention has a surface rubber layer on one side of a compressible layer via an adhesive rubber layer. The other surface of the layer was provided with a fiber cloth via an adhesive rubber layer, and the compressible layer was constituted of at least one of a double or a multilayer fabric.

Further, the printing blanket of the present invention is characterized in that in the compressible layer, the warp yarn obtained by twisting a plurality of yarns in the compressible layer has a thickness of 10 to 30 or more. Within the range of No. 30 to No. 60, 2
70-130 warp yarns per 5.4 mm
The configuration was such that the number of yarns for weft and weft yarns was in the range of 200 to 400.

In the present invention as described above, the compressible layer having the adhesive rubber layers on both sides has good waist strength (high rigidity) for facilitating the mounting work on the blanket cylinder. It has the function of providing the resilience and the flatness of the surface rubber layer necessary for performing a proper printing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below.

FIG. 1 is a schematic sectional view showing an embodiment of the printing blanket of the present invention. In FIG. 1, a printing blanket 1 of the present invention includes a surface rubber layer 4 on one surface of a compressible layer 2 via an adhesive rubber layer 3a.
The other surface is provided with a fiber cloth 5 via an adhesive rubber layer 3b, and on this fiber cloth 5, an adhesive layer 6 and a release sheet 7 are provided.

The compressible layer 2 is a layer for providing the printing blanket 1 with resilience necessary for performing good printing, and is composed of at least one of a double or multilayer fabric.

The double or multilayer fabric is a floating fabric having a structure in which a plurality of layers are three-dimensionally woven by warp (weft), such as a satin fabric and a twill fabric, and has a thickness of 0.1 mm.
It is about 1 to 0.8 mm. As specific examples of the double woven fabric and the multilayer woven fabric, a four-strand five-sheet satin fabric, a three-strand four-sheet satin fabric, and the like can be used.

The warp of the compressible layer 2 is formed by twisting a plurality of yarns, and the thickness thereof is equivalent to 5 to 60, preferably 10 to 60.
It is equivalent to No. 30 and the weft is also obtained by twisting a plurality of yarns, and its thickness is preferably about No. 30 to No. 60.
If the warp yarn obtained by twisting a plurality of yarns has a thickness of less than No. 5 or the weft yarn obtained by twisting a plurality of yarns has a thickness of less than No. 30, the surface rubber may be uneven due to the unevenness of the compressible layer 2. The flatness of the surface of the layer 4 is undesirably reduced. When the thickness of the warp yarn obtained by twisting a plurality of yarns exceeds the number 60 or the thickness of the weft yarn obtained by twisting a plurality of yarns exceeds the number 60, the cushioning property of the compressible layer 2 is increased. And the restoring property of the blanket 1 becomes insufficient.

The number of warp yarns per 25.4 mm of the compressible layer 2 is about 70 to 130, and 25.4 m.
The number of wefts per m is preferably about 200 to 400. If the number of implants is out of the above range, the resilience and surface flatness of the blanket 1 decrease, which is not preferable.

As the double or multi-layer fabric constituting the compressible layer 2, a fabric produced using synthetic fibers can be used. In this case, a heat fusion treatment is performed by utilizing the heat fusibility of the synthetic fibers. The warp yarn and the weft yarn may be fixed.

The adhesive rubber layers 3a and 3b are formed by solidifying the adhesive rubber impregnated in the compressible layer 2 in the manufacturing process, and fix the surface rubber layer 4 and the fiber cloth 5 to the compressible layer 2. It is. Therefore, although not shown in the drawing, the inside of the compressible layer 2 is also impregnated with the adhesive rubber material.

The adhesive rubber layers 3a and 3b can be formed using rubber materials such as nitrile butadiene rubber (NBR), ethylene propylene non-conjugated diene rubber (EPDM), and nitrile rubber (NR). The thickness is preferably about 0.01 to 0.30 mm.

Surface rubber layer 4 constituting blanket 1
Can be formed using a conventionally known blanket rubber material. Specifically, nitrile butadiene rubber (NBR), ethylene propylene non-conjugated diene rubber (EPDM), nitrile butadiene isoprene rubber (N
BIR), butadiene rubber (BR), and the like, or a mixture of two or more of these. The thickness of the surface rubber layer 4 can be set in a range of about 0.1 to 0.5 mm.

As the fiber cloth 5 constituting the blanket 1, a fiber cloth such as cotton, polyester fiber, polyvinyl alcohol fiber or the like can be used. Such a fiber cloth 5
The thickness of the warp is preferably 10 to 60, the thickness of the weft is preferably about 10 to 60, the number of warp yarns per 25.4 mm is about 20 to 100, and the number of weft yarns per 25.4 mm is 50. About 200 is preferable. The thickness of the fiber cloth 5 is preferably about 0.05 to 0.40 mm.

The adhesive layer 6 simplifies the operation of attaching a blanket to a small-diameter blanket cylinder unique to a business form printing machine, and includes a conventionally known acrylic (polybutyl acrylate, polydiethylhexyl acrylate, etc.) or the like. Is applied to a thickness of about 10 to 200 μm.

The release sheet 7 may be a conventionally known release sheet, for example, a sheet obtained by subjecting a paper to a release treatment, a resin film having a release property with respect to an adhesive, or the like.

In such a blanket 1, the thickness from the surface rubber layer 4 to the fiber cloth 5 is about 0.7 to 1.5 mm,
Preferably it is about 0.85 to 1.05 mm.

The blanket of the present invention as described above can be easily mounted on the blanket cylinder by the stiffness (high rigidity) given by the compressible layer 2 having the adhesive rubber layers 3a and 3b on both sides. Good printing is possible due to the resilience and the flatness of the surface rubber layer 4 which are given at the same time.

When the blanket is mounted by mechanically fixing the end of the blanket in the groove of the blanket cylinder, the adhesive layer 6 and the release sheet 7 are not required.

[0026]

Next, the present invention will be described in more detail with reference to examples.

Example 1 A compressible layer having a thickness of about 0.1 mm was used.
50mm, the thickness of the warp made by twisting multiple yarns is 2
Equivalent to No. 0, the thickness of the weft made by twisting multiple yarns is 4
A No. 0 equivalent, a satin fabric (C-40 manufactured by Teijin Limited) having 100 warp yarns per 25.4 mm and 300 weft yarns was prepared.

NBR is used as an adhesive rubber material for this satin fabric.
Then, a surface rubber layer (thickness 0.30 mm) made of NBR was laminated on one surface, and a fiber cloth was laminated on the other surface. The fiber cloth is a plain weave (manufactured by Teijin Limited) having a warp yarn number of 24, a weft yarn number of 20, a number of warp yarns per 25.4 mm of 50, and a number of weft yarns of 120. C-30) was used.

The thickness of the surface rubber layer, the adhesive rubber layer, the compressible layer, the adhesive rubber layer, and the blanket which is a laminate of the fiber cloth is 0.95 mm, and the thickness of each adhesive rubber layer is about 0.95 mm. It was 0.03 mm.

Next, a release sheet having an adhesive layer of polybutyl acrylate and having a thickness of 80 μm was attached to a fiber cloth to obtain a blanket as shown in FIG.

(Example 2) As a compressible layer, a thickness of about 0.3 mm was used.
55mm, warp made by twisting multiple yarns has a thickness of 2
Equivalent to No. 5, the thickness of the weft yarn obtained by twisting multiple yarns is 5
Example 1 except that a satin woven fabric (B-90, manufactured by Teijin Limited) having No. 0 equivalent and 110 warp yarns and 350 weft yarns per 25.4 mm was used.
A blanket was produced in the same manner as described above.

The thickness of the laminate of the surface rubber layer, the adhesive rubber layer, the compressible layer, the adhesive rubber layer, and the fiber cloth of the blanket is 0.95 mm, and the thickness of each adhesive rubber layer is about 0.95 mm. It was 0.03 mm.

(Comparative Example 1) The same plain woven fabric as that used in Example 1 was impregnated with NBR as an adhesive rubber material, and a surface rubber layer made of NBR (thickness 0.30 m)
m) was laminated, and on the other surface, the same satin fabric as that used in Example 1 was laminated to form a compressible layer.

The thickness of the blanket, which is a laminate of the surface rubber layer, the adhesive rubber layer, the fiber cloth, the adhesive rubber layer, and the compressible layer, is 0.95 mm, and the thickness of the adhesive rubber layer is about 0 mm. 0.03 mm.

Next, a release sheet having an adhesive layer made of polybutyl acrylate and having a thickness of 80 μm was bonded to the compressible layer to obtain a blanket (Comparative Example 1).

(Comparative Example 2) As the compressible layer, a thickness of about 0.
60mm, the thickness of the warp made by twisting multiple yarns is 8
Equivalent to the number, the thickness of the weft made by twisting multiple yarns is 20
No. equivalent, 6 warp yarns per 25.4 mm
A blanket (Comparative Example 2) was produced in the same manner as in Example 1 except that a satin woven fabric (B-45, manufactured by Teijin Limited) having 0 weft threads and 160 weft threads was used.

The thickness of the laminate consisting of the surface rubber layer, the adhesive rubber layer, the compressible layer, the adhesive rubber layer and the fiber cloth of this blanket is 0.95 mm, and the thickness of each adhesive rubber layer is about 0.95 mm. It was 0.03 mm.

(Evaluation of Blanket) The waist strength (rigidity) of each blanket (Examples 1-2 and Comparative Examples 1-2) produced as described above was evaluated by the following feeling measurement. Restorability was evaluated by the following measurement method. The flatness of the surface rubber layer was evaluated by the following method. The results are shown in Table 1 below.

Hand feeling measurement method A test piece of 3 × 15 cm was prepared, one end was fixed to a surface plate, and the other end was protruded 13 cm horizontally from the surface plate. The bending angle of the test piece is measured to determine the feeling. The range of the feel that facilitates the work of attaching to the blanket cylinder is 30 to 50 degrees with the release sheet, and 60 to 50 degrees without the release sheet.
It is in the range of 80 °.

Restorability measurement method A blanket was placed on a measuring table with the surface rubber layer facing upward, the compression area was 3.0 cm ² (circular anvil), the initial load was 3.0 kg, and the compression speed was 1.0 ± 0. At 0.1 mm / min (the final 0.005 mm compression rate is 0.3 mm / min), the blanket is compressed 0.10 mm with the initial load being 0, and the stress after a holding time of 1.0 second is measured. The resilience that enables good printing is that the stress is 50 to 90 (kgf / 3 cm).
² ) range.

Evaluation method of flatness of surface rubber layer Solid printing is performed by a printing machine, and unevenness of the ink density of the printed matter is examined. The judgment is made by using a reflection densitometer, dividing the printed matter into 25 points of 2 × 2 mm square, measuring each density in the partition, and evaluating the dispersion. The flatness enabling good printing is in a range where the density difference is 0.05 or less.

[0042]

[Table 1] As shown in Table 1, the blanket of the present invention (Examples 1 and 2) has a feeling of 30 to 50 ° (with a release sheet) and 60 to 80 ° (without a release sheet). )
And the resilience is 50 to 90 (kgf / c
m ² ), it was confirmed that the work for mounting on the blanket cylinder was easy, the flatness of the surface rubber layer was excellent, and good printing was possible.

On the other hand, in the blanket of Comparative Example 1, the positions of the compressible layer and the fiber cloth were opposite to those of the blanket of Example 1, and although the restorability was good, the strength of the waist (rigidity) was high. Height) was insufficient.

The blanket of Comparative Example 2 was easy to mount on a blanket cylinder and had good resilience, but the flatness of the surface rubber layer was insufficient.

[0045]

As described in detail above, according to the present invention, a surface rubber layer is formed on one surface of a compressible layer made of at least one of a double or multilayer fabric via an adhesive rubber layer.
Since the printing blanket is formed by forming a fiber cloth on the other surface of the compressible layer with an adhesive rubber layer interposed therebetween, the waist strength (high rigidity) provided by the compressible layer having an adhesive rubber layer on both surfaces is provided. ) Facilitates the work of mounting on the blanket cylinder, and at the same time provides good printing due to the resilience and flatness of the surface rubber layer, which is excellent for workability in business form printing machines. It can exhibit printability.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a printing blanket of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Blanket 2 ... Compressible layer 3a, 3b ... Adhesive rubber layer 4 ... Surface rubber layer 5 ... Fiber cloth 6 ... Adhesive layer 7 ... Release sheet

Claims (2)

[Claims] 1. A compressible layer having a surface rubber layer on one surface with an adhesive rubber layer interposed therebetween, a fiber cloth on the other surface of the compressible layer with an adhesive rubber layer interposed therebetween, and A printing blanket comprising at least one of a double or multilayer fabric. 2. The compressible layer according to claim 1, wherein the warp yarn obtained by twisting a plurality of yarns has a thickness of 10 to 30 or more, and the weft yarn obtained by twisting a plurality of yarns has a thickness of 30 to 60. Within a considerable range, the number of driven warp yarns per 25.4 mm is 7
2. The printing blanket according to claim 1, wherein the number of the wefts is 0 to 130 and the number of the wefts is 200 to 400. 3.