JP6357569B1 - Blanket for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing blanket that can be used in a narrow gap method and that can suppress or prevent the occurrence of peeling and misalignment of each layer of the blanket. A printing blanket according to an embodiment includes a base material, a compressed rubber layer provided thereon, a reinforcing cloth provided thereon, and a surface rubber layer provided thereon. It has a tail end side and a tail end side. A cutout groove is provided in the tail end portion in the thickness direction of the tail end portion from the surface of the surface rubber layer. A first band plate is provided in the cutout groove, and a second band plate is provided on the surface opposite to the surface rubber layer at the tail end side. [Selection] Figure 1

Description

  The present invention relates to a printing blanket for use in an offset printing press.

  A blanket used for offset printing is generally provided with a base material on which 2 to 4 base fabrics are fixed with an adhesive, a sponge rubber layer (compressed rubber layer) provided on the upper surface, and further thereon. A surface rubber layer.

  Such a blanket is used by being mounted on a blanket cylinder. As a method for attaching a blanket, there is a method using a tension bar. In this method, a blanket is used in which both ends, that is, the tail end and the tail end are covered with a U-shaped metal bar (insertion bar). The blanket cylinder includes a hole and two tension bars that are built into the hole and have a cut portion. To attach this blanket to the blanket cylinder, insert the insertion bar at the end of the blanket into the hole through the hole opening (gap) provided on the surface of the blanket cylinder, and cut one of the tension bars. Insert into the insert. Next, the blanket is wound while being pulled around the blanket cylinder. Next, the insertion bar at the tail edge side end portion is inserted into the hole through the gap, and further inserted into the cut portion of the other tension bar. The blanket is fixed to the blanket cylinder by rotating and tightening both tension bars.

  However, in this method, since the insertion bar is thick, it is necessary to increase the gap of the blanket cylinder. Therefore, the portion that cannot be used for printing on the blanket increases accordingly. When the gap is large, a large impact or vibration occurs when the plate cylinder or the impression cylinder comes into contact with the portion corresponding to the gap of the blanket. For this reason, it is difficult to increase the printing speed, and the printing efficiency is lowered.

  Therefore, in order to increase the portion that can be used for blanket printing and to reduce the impact or vibration to improve the printing speed, a narrow gap method is adopted in which the gap is narrowed (Japanese Patent Laid-Open No. 7-285214). etc). In this method, in order to be able to insert the end of the blanket into the narrow gap, for example, instead of a thick insertion bar with a U-shaped cross section, a thin strip is fixed to the base-side surface of each end of the blanket with an adhesive. doing. According to this method, the tail end of the blanket is inserted into the gap of the blanket cylinder having the same structure as that described above so that the band plate faces the hole inner surface. Next, the blanket is wound while being pulled around the blanket cylinder. At this time, the blanket is bent at the blanket portion in the vicinity of the band plate and suspended on the wall portion of the blanket cylinder. Next, the tail edge side end portion to which the band plate is attached is inserted into the hole through the gap, and further inserted with the band plate into the cut portion of the tension bar. Then, the blanket is fixed to the blanket cylinder by rotating the tension bar and moving the tail edge side end portion between the tail end portion and the tension bar and tightening. In such a blanket, since the band plate fixed to the end portion thereof is relatively thin, the gap provided in the blanket cylinder can be narrowed. As a result, the area that can be used for blanket printing can be expanded, and in addition, impact and vibration can be reduced and printing speed can be improved.

JP 7-285214 A

  However, since the band plate used in the narrow gap method fixes only the surface of the blanket on the substrate side, tensile stress is applied to the end portion on the tail side when it is wound around the blanket cylinder. The tensile stress acts between the members having a weak bonding force of the blanket, for example, between the base fabrics of the base material, and the blanket is peeled between the base fabrics. As a result, the blanket is displaced in the circumferential direction of the blanket cylinder, and printing duplication occurs. Moreover, even when not peeling, double members are generated when the members of the blanket are displaced in the circumferential direction.

  An object of the present invention is to provide a printing blanket that can be used in a narrow gap method and that can suppress or prevent the occurrence of peeling and misalignment of each layer of the blanket.

  The printing blanket according to the embodiment includes a substrate, a compressed rubber layer provided on the substrate, a reinforcing cloth provided on the compressed rubber layer, and a surface rubber layer provided on the reinforcing cloth. Is provided. The blanket has a tail end side and a tail end side. A cutout groove is provided in the tail end portion in the thickness direction of the tail end portion from the surface of the surface rubber layer. A first band plate is provided in the cutout groove, and a second band plate is provided on the surface opposite to the surface rubber layer at the tail end side.

  According to the present invention, it is possible to provide a printing blanket that can suppress or prevent the occurrence of peeling and misalignment of each layer of the blanket and can reduce printing duplication when used in the narrow gap method.

It is a schematic diagram which shows an example of the printing blanket of embodiment. It is a schematic diagram which shows an example of the printing blanket of embodiment. It is a schematic diagram which shows an example of the printing blanket of embodiment. It is a schematic diagram which shows an example of the printing blanket of embodiment. It is sectional drawing which shows the mounting method of the blanket of embodiment. It is a schematic diagram which shows the measuring jig used in the example.

  Hereinafter, embodiments will be described with reference to the drawings. The drawings are schematic and are not to scale.

  Fig.1 (a) is a schematic diagram which shows the tail end part of the printing blanket of embodiment. The printing blanket 1 includes a base material 2, a compressed rubber layer 3, a reinforcing cloth 4, and a surface rubber layer 5.

  The base material 2 includes base fabrics 2a, 2b and 2c. The base cloth 2a and the base cloth 2b are bonded to each other with a rubber layer 2d, and the base cloth 2b and the base cloth 2c are bonded to each other with a rubber layer 2e. As the base fabric and the rubber layer, known base fabrics and rubber materials used for printing blankets can be used. For example, a woven fabric, a nonwoven fabric, etc. can be used for a base fabric. Woven fabric, non-woven fabric, for example, from fibers such as cotton, wool, hemp, silk, rayon, cupra, acetate, nylon, vinylon, polyester, polyvinyl chloride, acrylic, acrylate, polyimide, carbon fiber, aramid fiber or glass fiber Can be made. The weaving method of the base fabric is not particularly limited, and examples thereof include plain weave, twill weave, and satin weave. The rubber layer is not particularly limited, and examples thereof include acrylonitrile-butadiene rubber, chloroprene rubber, fluorine rubber, polyurethane rubber, ethylene propylene rubber, and butyl rubber. In this example, the base material 2 includes three base cloths, but the base cloth may be two sheets or three or more base cloths.

  The thickness of the substrate 2 is preferably 0.8 to 1.2 mm, for example. The plurality of base fabrics may all be the same base fabric. However, it is preferable that the base fabric on the surface rubber layer 5 side has higher strength than the other base fabrics. In that case, peeling or deviation can be further prevented.

  The compressed rubber layer 3 is provided on the base material 2. As the compressed rubber layer 3, a known compressed rubber layer used for a printing blanket can be used. The compression rubber layer 3 is not particularly limited, and is, for example, sponge rubber made of acrylonitrile-butadiene rubber, chloroprene rubber, fluorine rubber, polyurethane rubber, ethylene propylene rubber, butyl rubber, or the like. The thickness of the compressed rubber layer 3 is preferably 0.1 mm or more and 2.0 mm or less, for example.

  The reinforcing cloth 4 is provided on the compressed rubber layer. For example, the reinforcing cloth 4 may be the same as the above-described base cloth. By providing such a reinforcing cloth 4, for example, when the blanket 1 is wound around the blanket cylinder and used, an elastic layer (for example, a rubber layer or a compressed rubber layer) is reinforced and sheared in the printing direction. The effect of suppressing displacement against force is improved.

  The surface rubber layer 5 is provided on the reinforcing cloth 4. The material of the surface rubber layer 5 can be a known material used for a printing blanket. For example, the surface rubber layer 5 is not particularly limited as a material, but includes, for example, nitrile rubber, natural rubber, styrene butadiene rubber, chloroprene, butyl rubber, ethylene propylene rubber, chlorosulfonated polyethylene, silicone rubber, or fluorine rubber. The thickness of the surface rubber layer 5 is preferably 0.4 to 0.5 mm, for example. For example, the surface rubber layer 5 may be bonded to the reinforcing cloth 4 with the rubber layer 6.

  The blanket 1 has a desired width depending on the application. The width is, for example, 400 to 1100 mm.

  The blanket 1 has a tail end part shown in FIG. 1A and a tail end part not shown. A notch groove 5 a is provided at the end of the blanket 1 from the surface of the surface rubber layer 5 in the thickness direction of the end of the end of the blanket 1. As will be described in detail later, the first groove plate 7a is provided in the notch groove 5a, and a second surface is formed on the surface opposite to the surface rubber layer 5 at the tail edge side end (for example, the back surface of the substrate 2). A strip 8 is provided.

The total thickness _{t w1} of such leading edge side end portion is in the range of 1.9～4.0Mm. The total thickness is the thickness of the end of the blanket 1 on the end side. That is, the total thickness includes the base material 2 of the blanket 1 that does not include the first belt plate 7a and the second belt plate 8, the compression rubber layer 3, the reinforcing cloth 4, and the surface rubber layer 5. It is a value obtained by subtracting the depth value of the notch groove 5a from the thickness value and adding the thickness values of the first strip 7a and the second strip 8 to each other. When the total thickness _tw1 is within such a range, the blanket end portion of the blanket 1 can be inserted into the gap of the narrow gap type blanket cylinder and attached. When t _w1 is less than 1.9 mm, the blanket 1 may not have sufficient strength. When the t _w1 is more than 4.0mm, there is a risk that it becomes difficult to be inserted into the gap when mounted on the blanket cylinder. The total thickness _{t w1,} if 2.2～2.8Mm, blanket has a sufficient strength, and more preferable because the easily inserted into the gap.

For example, a suitable combination of factors such as the thickness of the base material 2, the compressed rubber layer 3, the reinforcing cloth 4 and the surface rubber layer 5, the depth of the notch groove 5a and / or the thickness of two strips described later is selected. By doing so, the total thickness _tw1 of the end portion on the side of the blanket 1 can be set to the above value.

  The cutout groove 5a, the first strip 7a, and the second strip 8 will be described in detail below.

  An example of the notch groove is shown in FIG. FIG. 1B is a perspective view of the blanket 1 excluding the first band plate 7 a and the second band plate 8. The notch groove 5a is provided from the surface of the surface rubber layer 5 in the thickness direction of the grip side end portion over the entire width of the grip side end portion of the blanket 1 (arrow shown in FIG. 1B). It is a groove.

The depth t ₁ (see FIG. 1A) of the notch groove 5a is a depth corresponding to any thickness from the upper surface of the surface rubber layer 5 to the lower surface of the surface rubber layer. That is, the depth t ₁ is provided in a region from the upper surface to the lower surface of the surface rubber layer as shown in FIGS. 1A and 1B and may be the same as the thickness of the surface rubber layer 5.

Alternatively, it may be smaller than the thickness of the surface rubber layer 5. Such an example is shown in FIG. In this example, the notch groove 5 b is provided in a region above the lower surface from the upper surface of the surface rubber layer 5, and the depth t ₂ of the notch groove 5 b is smaller than the thickness of the surface rubber layer 5.

  In still another embodiment, the depth of the notch groove 5 a may be a depth from the upper surface of the surface rubber layer 5 to the lower surface of the rubber layer 6. That is, the depth of the notch groove 5 a may be in a range from the upper surface of the surface rubber layer 5 to a region above the upper surface of the reinforcing cloth 4.

  When the end of the blanket 1 is attached to the blanket cylinder, tensile stress is applied to the notch groove 5a in which the first strip 7a is disposed. As described above, the depth of the notch groove in which the first strip is disposed is defined within the range from the surface of the surface rubber layer to the lower surface of the rubber layer at the end, and the depth of the notch groove is maximized. Even so, by configuring the reinforcing cloth at the bottom of the notch groove, even if a tensile stress is applied to the notch groove on which the first band plate is disposed, the structure of the tail end portion starting from the notch groove is used. It is possible to avoid peeling or breaking between members. For example, the breaking strength is 20 kgf / cm to 70 kgf / cm, and it is difficult to break during use.

  In particular, as shown in FIG. 2, by making the depth of the notch groove 5b smaller than the thickness of the surface rubber layer 5, that is, by leaving a part of the surface rubber layer 5 at the bottom of the notch groove 5b, Separation and breakage between the members at the tail end portion can be avoided more effectively.

The cutout groove 5a is provided with a first strip 7a (see FIG. 1A). The first strip 7a is to fill the cutout groove 5a, is provided over the entire width of the tail edge side end portion, the width w ₁ of the first strip 7a is a notched groove 5a The length is preferably the same as the width. Thus, for example, the width of the cutout groove 5a may be determined according to the width w ₁ of the first strip 7a. Width _{w 1} of the first strip 7a is, for example, 12～30Mm. If it is 20-30 mm, since it will become difficult to produce peeling and / or a shift | offset | difference, it is more preferable.

  As the material of the first strip 7a, for example, carbon-based, manganese-chromium-based steel can be used. As the material, for example, spring steel, that is, spring steel or the like is preferably used because the first strip 7a is more stable in the blanket cylinder and the blanket 1 can be firmly fixed by the blanket cylinder.

For example, the thickness of the first strip 7a is preferably 0.2 to 1.2 mm. For example, it is preferable that the thickness of the first strip 7 a is the same as the depth t ₁ of the notch groove 5 a and the upper surface thereof is flush with the upper surface of the surface rubber layer 5. However, the upper surface of the first strip 7 a may be higher than the upper surface of the surface rubber layer 5. Such an example is shown in FIG. In this example, the upper surface of the first strip 7 c provided in the notch groove 5 c is made higher than the upper surface of the surface rubber layer 5. In such a case, the difference Δ between the upper surface of the first strip 7c and the surface rubber layer 5 is preferably, for example, 0 to 0.8 mm.

The 2nd strip | belt board 8 is provided in the surface on the opposite side to the surface rubber layer 5 of the tail end side part (refer Fig.1 (a)). The 2nd strip 8 is provided over the whole width direction of the tail end side part. The width w ₂ (see FIG. 1A) of the second strip 8 is preferably 12 to 30 mm, for example. If it is 20-30 mm, since the blanket 1 is fixed to a blanket cylinder more firmly, it is more preferable. Width w ₂ of the second strip 8 may be the same as the width w ₁ of the first strip 7a, it may be larger than the width w _1.

  The thickness of the second strip 8 is preferably 0.2 to 1.2 mm, but a thicker one is more preferable because the blanket is more firmly fixed to the blanket cylinder. The thickness of the second strip may be thicker than the thickness of the first strip.

  As the material of the second strip 8, for example, carbon or manganese chrome steel can be used. The material of the second strip 8 may be the same as the material of the first strip 7a, for example.

  Each of the first strip 7a and the second strip 8 is attached to a desired position by, for example, an adhesive (not shown). As the adhesive, a heat adhesive film or an adhesive such as an epoxy resin or urethane rubber can be used.

  The end portion (not shown) of the blanket 1 may be a known configuration that can be inserted into the hole and fixed through the gap of the narrow gap type blanket cylinder. For example, a band plate similar to the second band plate may be provided on the surface opposite to the surface rubber layer at the tail edge side end.

  In a further embodiment, the first strip and the second strip of the printing blanket may be integral. An example of this blanket is shown in FIG. FIG. 4 is a schematic diagram showing a tail end portion of a printing blanket.

  The printing blanket 10 of this example includes a base material 12, a compressed rubber layer 13 provided on the base material 12, a reinforcing cloth 14 provided on the compressed rubber layer 13, and a reinforcing cloth 14. And a provided surface rubber layer 15. For example, as the base material 12, the compressed rubber layer 13, the reinforcing cloth 14, and the surface rubber layer 15, the same materials as those described above can be used.

  The printing blanket 10 has a tail end portion shown in FIG. 4 and a tail end portion (not shown), and a notch groove 15a is provided in the thickness direction of the surface rubber layer 15 at the tail end portion. Yes. The cutout groove 15a may have the same configuration as any of the above cutout grooves, for example.

  At the end of the blanket 10, the first strip and the second strip are connected together at the end of the grip end, that is, a strip 17 having a U-shaped cross section. Is provided. The surface rubber layer side plate (hereinafter referred to as “front side plate”) 17a of the band plate 17 is provided corresponding to the shape of the notch groove 15a.

The total thickness _{t w2} of the tail edge side end portion of the blanket 10, it is preferable that at in the range of same 1.9~4.0mm blanket 1 shown in FIG. 1, in 2.2~2.8mm More preferably. The total thickness _tw2 is the thickness of the end of the blanket side end portion of the blanket 10. That is, the total thickness of the notch groove 15a is determined from the thickness value including the base material 12 of the blanket 10 that does not include the band plate 17, the compression rubber layer 13, the reinforcing cloth 14, and the surface rubber layer 15. This is a length obtained by subtracting the depth value and adding the thickness values of the front side plate 17a and the back side plate 17b of the band plate 17.

For example, the thickness of the base material 12, the compressed rubber layer 13, the reinforcing cloth 14, and the surface rubber layer 15, the depth of the notch groove 15a, the thickness of the front side plate 17a, and / or the thickness of the back side plate 17b of the band plate 17 and the like. combining factors properly by selecting the total thickness t _w2 of the tail edge side end portion of the blanket 1 may be the value of the.

  For example, the thickness of the front side plate 17a may be the same as that of the first strip. Further, the thickness of the back side plate 17b may be the same as that of the second band plate. The thickness of the back side plate 17b may be thicker than the thickness of the front side plate 17a. The upper surface of the front side plate 17 a may be higher than the upper surface of the surface rubber layer 5.

  An example of a procedure for mounting the blanket of the embodiment described above on the blanket cylinder will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view of the blanket cylinder when the printing blanket 1 of FIG. 1 is mounted. The blanket cylinder 90 has a hole 91 therein, and a tension bar 92 is incorporated therein. The tension bar 92 is formed with a fixing cut portion 93. On the surface of the blanket cylinder 90, a gap 94 which is an opening of the hole 91 is provided.

To install the blanket 1 for printing on this blanket cylinder 90,
First, the tail edge side end portion 3 of the blanket 1 is inserted into the hole 91 through the gap 94 and inserted into the fixing cut portion 93 of the tension bar 92 (FIG. 5A). Next, the tension bar 92 is rotated in the direction of the dashed arrow (counterclockwise direction) (FIG. 5B). This prevents the tail edge side end 3 from coming off the tension bar when the blanket is wound around the blanket. Subsequently, the blanket cylinder 90 is rotated in the same direction, and the printing blanket 1 is wound around the blanket cylinder 90 so that the surface rubber layer 5 side is positioned outside, and then the end 2 on the grip side of the blanket 1 is blanketed. It is inserted into the hole 91 through the gap 94 of the barrel 90 (FIG. 5C). At this time, it is inserted so that the first band plate 7 a side of the tail end 2 is opposite to the surface rubber layer 5 on the tail end 3. Next, the blanket 1 is fixed to the blanket cylinder 90 by further rotating and tightening the tension bar 92 in the same direction (FIG. 5D). At this time, the blanket 1 in the vicinity of the second strip 8 is bent at the tail end 2 so that the wall 95 of the blanket cylinder 90 located under the gap 94 and the hole 91 in the vicinity of the tail butt. Suspended on a surface rubber layer located at

  In the printing blanket thus mounted, when the blanket cylinder 90 is rotated in the clockwise direction, for example, when used, the reaction is counterclockwise as shown in FIG. 5C (the direction of the white arrow). Tensile stress is generated. The tensile stress is applied to each member from the surface rubber layer 5 side toward the base material 2. In the embodiment, the surface rubber layer side is extended in the stress direction by providing a first side plate or a front side plate of a U-shaped cross section in the cutout groove of the surface rubber layer at the tail edge side end, and / or Misalignment is prevented. Therefore, delamination that occurs between the members or displacement of each layer in the stress direction can be made less likely than in the past. Further, when the first strip and the second strip are integrated, the first strip, that is, the front side plate, is prevented from being displaced in the stress direction, and therefore, more peeling and / or displacement is caused. A prevented printing blanket is provided.

  Further, by arranging the first strip in a notch groove provided in the thickness direction of the tail end portion from the surface of the surface rubber layer 5 at the tail end portion, the first strip plate is provided on the surface. It is possible to suppress or avoid an increase in the total thickness of the tail end portion due to the arrangement in the rubber layer. As a result, it is possible to provide a blanket that can accommodate a narrow gap type blanket cylinder having a narrow gap.

  The printing blanket described above can be mounted on a narrow gap type blanket cylinder having a narrow gap, and can suppress or prevent the peeling and misalignment of each layer of the blanket during use. Therefore, the blanket according to the embodiment can expand the area that can be used for printing, and also enables printing that is less likely to cause shock and vibration due to the gap and that can suppress or prevent the occurrence of sag.

[Example]
Example 1
An example of investigating the deformation rate of the blanket of the embodiment is shown below.

-Creation of blanket piece A blanket piece having a width of 4 cm and a length of 25 cm comprising a base material including four base fabrics, a compressed rubber layer, a reinforcing cloth, and a surface rubber layer (thickness 0.5 mm) was prepared.

-Formation of a notch groove and sticking of a strip board The above-mentioned blanket piece was used to produce the following three printing blankets of Example 1, Example 2, and Comparative Example 1.

Example 1
A cutout groove having a thickness of 0.2 mm and a width of 4 cm was formed in the surface rubber layer at the end of the blanket piece. A first strip made of spring steel having a thickness of 0.2 mm, a width (length in the longitudinal direction of the blanket piece) of 2 cm, and a length (length in a direction perpendicular to the longitudinal direction of the blanket piece) of 4 cm is formed in the cutout groove. The plate was affixed using urethane rubber (adhesive). Further, a second strip made of spring steel having a width of 2 cm, a length of 4 cm, and a thickness of 0.5 mm was attached to the base-side surface of the tail end portion using urethane rubber. The total thickness of the blanket end portion of this blanket was 2.6 mm.

(Example 2)
A notch groove having a thickness of 0.4 mm and a width of 2 cm was formed on the surface rubber layer at the end of the blanket piece. A strip having a length of 4 cm, a width of 4 cm, and a thickness of 0.5 mm was bent and attached to the end of the blanket piece. The strip was made of spring steel and was attached using urethane rubber. The width | variety of the surface side and back surface side of the folded strip was 2 cm, respectively, and it attached so that the surface side of a strip might follow a notch groove. The total thickness of the blanket side edge of this blanket was 2.7 mm.

(Comparative Example 1)
A strip made of spring steel having a width of 2 cm, a length of 4 cm, and a thickness of 0.5 mm was affixed to the surface of the blanket piece at the end of the grip side using urethane rubber. The total thickness of the blanket side edge of this blanket was 2.7 mm.

-Application of tensile stress and measurement of deformation rate Tensile stress was applied to the printing blanket of Example 1 above. Fig.6 (a) shows the schematic diagram of the measurement jig | tool 200 for giving a tensile stress to a blanket. The fixing part 201 of the measuring jig 200 has a gap 202 that reproduces the tail end side wall part of the blanket cylinder gap. The tail end 101 of the printing blanket 100 of Example 1 was inserted into the gap 202. An enlarged schematic diagram of the enclosure B in FIG. 6A is shown in FIG. As shown in FIG. 6B, the blanket 100 is inserted such that the front rubber layer 102 side of the tail end portion 101 faces downward. Prior to the application of tensile stress, reference lines 110a, 110b, and 110c parallel to the thickness direction of the blanket 100 were written on the side surface of the blanket end portion 101 of the blanket 100. Next, the gripping side of the blanket 100 was pinched with the chuck 104, and a tensile stress was applied in the direction of the arrow. This direction is the same as the direction in which tensile stress is applied when the blanket is mounted on the blanket cylinder and used. The tensile stress was applied up to 5000 N at a speed of 10 mm / min.

  After applying the tensile stress, the deformation rate of the blanket was measured. FIG.6 (c) is a schematic diagram which shows the mode after tension | tensile_strength provision of FIG.6 (b). Due to the application of tensile stress, the surface rubber layer side of the blanket shifted in the tensile stress direction. Accordingly, the lower ends of the reference lines 110a, 110b, and 110c are shifted to the left side. The deformation rate was calculated using the following equation 1 using the width a of the strip and the length b of the lower end of the reference lines 110a, 110b, 110c.

Deformation rate = b / a * 100 (1)
Moreover, the presence or absence of delamination was observed visually. The same experiment was performed on the printing blankets of Example 2 and Comparative Example 1.

The results are shown in Table 1.

  The deformation rate of the blankets of Examples 1 and 2 was about half that of Comparative Example 1. In Comparative Example 1, peeling occurred, whereas in the blankets of Examples 1 and 2, no peeling occurred. Therefore, according to the embodiment, it has been clarified that a blanket in which occurrence of displacement and peeling is prevented can be provided.

Example 2
The example which investigated the presence or absence of the shear peeling of the blanket of embodiment is shown below.

-Production of blanket piece A blanket piece having a width of 50 mm and a length of 150 mm having the same structure as the blanket piece of Example 1 was produced. Using this blanket piece, the blanket of Example 3 in which the band plate was pasted in the same manner as in Example 1, the blanket in Example 4 in which the strip plate was pasted in the same manner as in Example 2, and Comparative Example 1 A blanket of Comparative Example 2 in which a strip was attached in the same manner as in Example 1, was prepared.

A tensile stress was applied to each blanket using the same measurement jig as in Example 1. Tensile stress was applied to each of 500 cycles in which the stress was increased from 2.5 kN to 3.5 kN and then decreased from 3.5 kN to 2.5 kN at a speed of 300 mm / min in the direction of the arrow. After applying the tensile stress, the presence or absence of shear peeling at the gripping portion of the blanket was visually observed. The results are shown in Table 2.

  In the blanket of Comparative Example 2, shear peeling occurred at 350 cycles. On the other hand, in the blankets of Examples 3 and 4, no shear peeling occurred even after 500 cycles. Therefore, according to the embodiment, it has become clear that a blanket in which occurrence of peeling is prevented can be provided.

DESCRIPTION OF SYMBOLS 1, 10 ... Blanket for printing 2, 12 ... Base material 3, 13 ... Compression rubber layer 4, 14 ... Reinforcement cloth 5, 15 ... Surface rubber layer 5a, 5b, 5c, 15a ... Notch groove 7a, 7b, 7c ... No. 1 strip 8 8 second strip 17 17 strip

Claims (2)

A printing blanket comprising: a base material; a compressed rubber layer provided on the base material; a reinforcing cloth provided on the compressed rubber layer; and a surface rubber layer provided on the reinforcing cloth. Because
It has a tail end side and a tail end side,
The notch-side end portion is provided with a notch groove in the thickness direction of the end-side end portion from the surface of the surface rubber layer, and the notch groove extends from the upper surface to the lower surface of the surface rubber layer. In the area,
The printing blanket which provided the 1st strip in the said notch groove, and provided the 2nd strip on the surface on the opposite side to the surface rubber layer of the above-mentioned end side.   The printing blanket according to claim 1, wherein the first strip and the second strip are integrated.

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