JP2857017B2 - Rubber blanket for printing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber blanket, and more particularly to a printing blanket.

[0002]

2. Description of the Related Art As a printing rubber blanket, JP-A-63-249696 discloses a rubber blanket having a rubber surface layer and a plurality of or a single-layer rubber reinforcing base fabric laminated on the rubber surface layer. Have been. Here, the base fabric for rubber reinforcement is
It is configured using a spun yarn formed of an artificial long fiber yarn having a short fiber yarn adhered to the surface. Such a printing rubber blanket is used by printing the rubber reinforcing base fabric side around a printing press blanket cylinder during printing.

[0003]

The spun yarn constituting the rubber reinforcing base fabric used in the above-described printing rubber blanket is formed by simply attaching a short fiber yarn to the surface of an artificial long fiber yarn. Therefore, the long fiber yarn and the short fiber yarn cannot be entangled, and the space between them is loose. Therefore, when a tensile load is applied to such a spun yarn during printing, first, the short fiber yarn on the surface side is cut, and then the long fiber yarn is easily cut, and as a result, the yarn is likely to be cut. Therefore, the above-described rubber blanket for printing using the rubber reinforcing base fabric formed using such a spun yarn, when a tensile load is applied, specifically, the tensile load accompanying the mechanical operation during printing. Elongation tends to occur when added. When such an elongation occurs in the printing rubber blanket, there is a possibility that the printing position is shifted or the sharpness of the print is impaired. Therefore, when the above-described printing rubber blanket is used, it is necessary to periodically stop the operation of the printing press and retighten the printing rubber blanket. Therefore, when the printing rubber blanket described above is used, it is difficult to continuously operate the printing machine for a long time, and the printing efficiency is not good.

[0004] It is an object of the present invention to provide a printing blanket which does not easily elongate even under a tensile load during printing.

[0005]

SUMMARY OF THE INVENTION The inventor of the present invention provides a warp yarn with a twist factor of 3 · 3 as a means to elucidate the process of dimensional change that occurs during use of a printing rubber blanket.
Three types of blankets using 4.5 were prepared, and printing experiments were performed. And from the result, the cause of the growth of the printing rubber blanket is more than the fiber deterioration,
Due to slippage between the single fiber bundles forming the spun yarn, and the decrease in the thickness of the printing rubber blanket,
It was confirmed that the main base cloth weft crimp was in a compression crushed shape due to the impression pressure, and the present invention was completed.

That is, the printing rubber blanket according to the present invention includes a rubber surface layer and a rubber reinforcing base fabric laminated on the rubber surface layer. Here, the base fabric for rubber reinforcement uses a raw yarn composed of a core portion of a long fiber obtained by cutting a high-tensile chemical fiber to about 10 to 30 cm, and a yarn table of short fibers covering the surface of the core portion. In the raw yarn, the ends of the core are entangled and integrated with the short fibers of the yarn surface.

[0007] Such a printing rubber blanket further includes, for example, a compression layer disposed between a rubber surface layer and a rubber reinforcing base fabric. Here, the compression layer is
(A) Either one of the base fabric composed of warp and weft-bonded multi-structured weaving yarns having a wavy inclination and the base fabric composed of (b) the weft of multi-weft multi-structured using bulky processed yarns Or a laminate of both.

[0008]

The raw yarn forming the rubber reinforcing base fabric used in the printing rubber blanket of the present invention comprises the above-mentioned core and yarn table, and the end of the core is the short side of the yarn table. The fibers are entangled and integrated. In such a yarn, since the core portion and the yarn surface are entangled at the end of the core portion, slippage does not easily occur between the core portion and the yarn surface even under a tensile load, and the yarn is cut. Hateful. For this reason, the base fabric for rubber reinforcement formed by using such a raw yarn is hardly stretched and hardly deformed even under a tensile load.

When the printing rubber blanket of the present invention further includes the above-described compression layer, the bulge phenomenon generated by printing pressure during printing hardly occurs, and at the same time, an appropriate printing pressure is applied. Can be secured,
There is little risk of impairing print clarity.

[0010]

FIG. 1 shows a printing blanket according to an embodiment of the present invention. In the figure, a printing rubber blanket includes a rubber surface layer 1 and an auxiliary base cloth 2, a rubber adhesive layer 3, a main base cloth 4 (an example of a rubber reinforcing base cloth), a rubber adhesive layer 3, and a main base cloth 4 thereunder. (An example of a base fabric for rubber reinforcement) is laminated and arranged in this order.

As shown in FIG. 2B, the main base fabric 4 is a plain weave-like woven fabric composed of a warp yarn 5 and a weft yarn 6.
No. 0 single yarn is used. The density of the warp yarn 5 is 55
/ Inch and the weft yarn density is 60 / inch.

The main base cloth 4 is formed by using an original cloth as shown in FIG. This original fabric is a plain weave-like woven fabric composed of a warp yarn 5 and a weft yarn 6, and a core made of a long fiber obtained by cutting a high-tensile chemical fiber (thermoplastic chemical fiber) into about 10 to 30 cm as the warp yarn 5 and the weft yarn 6. An original yarn, for example, a blended yarn or a twisted yarn, comprising a portion and a yarn surface of short fibers having a length of up to about 5 cm covering the surface of the core portion is used. Since the core part is made of a long fiber obtained by cutting the high-tensile chemical fiber as described above to about 10 to 30 cm, the end of the core part, that is, the cut part is spread in a cotton-like manner. The end of the part is complicatedly entangled with the short fiber of the yarn surface and integrated.

[0013] Such a raw fabric has a wavy crimp in which the warp yarns 5 and the weft yarns 6 are balanced due to the shrinkage accompanying the production. The main base cloth 4 is formed by stretching the base cloth and removing the crimp of the warp yarns 5 to make the warp yarns 5 straight, so that the warp / weft-curved fabric of the base cloth is used as a weft-curved weft. And heat-setting (thermal fixing) in this state.

The auxiliary base fabric 2 is a warp-bent flat fabric (poplin grade) formed using finer yarns than the main base fabric 4. In addition, this auxiliary base cloth 2 can be omitted.

In such a printing rubber blanket, since the above-described raw yarn is used for the main base fabric 4, slippage between the core and the yarn surface is removed, and elongation is effectively prevented. You. That is, the yarn forming the main base cloth 4 is composed of the core and the yarn surface as described above, and the ends of the core are entangled and integrated with the short fibers of the yarn surface. When it is received, slippage is less likely to occur between the core and the yarn surface, and it is hard to cut. For this reason, the printing rubber blanket provided with the main base fabric 4 formed using such a yarn is hardly stretched and hardly deformed even when it is subjected to a tensile load while being attached to the printing press.

In the above-described yarn, the ends of the core together with the short fibers on the yarn surface can easily bite into the rubber adhesive layer 3 and can exert a good nailing effect on the rubber adhesive layer 3. For this reason, the printing rubber blanket can maintain the same flexibility as the conventional one, and can also enhance the adhesiveness between the main base fabric 4 and the rubber adhesive layer 3, thereby suppressing a dimensional change. Also, the deterioration of the buffer restorability is eliminated.

Further, in the above-mentioned base cloth 4, since the raw yarn forming the base cloth uses thermoplastic chemical fiber for the core, the crimp waveform of the weft yarn can be heat-fixed as shown in FIG. 2B. As a result, it is possible to prevent compression and crushing due to the printing pressure at the time of printing and maintain good buffering / restoring properties. For this reason, the printing rubber blanket is unlikely to cause a reduction in thickness due to printing pressure.

The short fiber spun yarn 20th yarn mainly used for the conventional rubber blanket for printing has a fiber length of about 5 cm or less and a twist coefficient K of 4, so that 5c
Although the number of twists t during m is about 36, the fiber used in this example has a fiber length of the core of 10 to 30 cm. 72-216t
Is twisted, and as a result, the frictional force between the fiber bundles is remarkably increased, and the slip prevention action is enhanced.

The main base fabric used for the conventional printing rubber blanket is a plain weave, and the weft density is 5%.
5 / inch and a cover factor K of about 17. Here, if the fiber length is 5 cm, approximately 1
It will have 10 warp / weft intersection points (texture points). On the other hand, the main base cloth 4 used in this embodiment
Then, the fiber length of the core part of the yarn forming the fiber is 10 to 30.
cm, so it is almost 220 to 660 in the meantime.
It will have a weft intersection point. Therefore, the twisting friction force of the main base cloth 4 is significantly increased as compared with the conventional base cloth,
Further, since the cross frictional force between the warp and the weft is increased, the slip preventing effect between the single fiber bundles is enhanced.

As a result, the effect of preventing the rubber blanket for printing of the present embodiment from extending can be enhanced. For this reason, the printing rubber blanket of the present embodiment is hardly stretched even when a tensile load accompanying a machine operation during printing is applied, so that there is little possibility that a printing position shift occurs or a loss of print sharpness is caused. Become. In addition, since the necessity of periodically stopping the operation of the printing press and retightening the printing rubber blanket is reduced, the printing press can be continuously operated for a long time.

The above-described printing rubber blanket may further include a compression layer P as shown in FIG. Here, the compression layer P is disposed between the auxiliary base fabric 2 and the rubber adhesive layer 3.

Such a compression layer P is made of, for example, a base fabric in which the warp yarns of the warp / weft bonding multiple structure are formed at a wavy inclination angle. FIG. 4 shows a specific example of such a base cloth. In FIG. 4, C indicates the one employing the simple binding method, and the binding yarn S is substantially perpendicular to the U-shape. D indicates the one employing the double binding method, and the binding yarn S has a V-shaped wavy shape with an arbitrary inclination angle. E is a fixed type (W-shaped)
This shows the one that adopts the binding method, in which the binding warp yarn S
Has an arbitrary inclination angle in a W-shaped wavy shape. Incidentally, the physical properties of the binding method, the binding warp yarn S, and the wavy inclination angle in the double binding method and the fixed binding method for forming such a base cloth are the hardness, softness, thickness, deviation, etc. of the printing material. In consideration of the above, it can be appropriately designed so as to be adapted to the printing purpose, and thereby, a desired compressibility can be imparted to the printing rubber blanket. Further, the compression layer P may have a binding warp having a sawtooth shape or a symmetrical shape.

When the base fabric in which the warp yarns of the above-described warp / weft bonding multiple structure are formed at a wavy inclination angle is used as the compression layer P, the pressure-resistant elasticity of the warp yarns S is used. As a result, a sufficient printing pressure can be held by the solid spring action of the connecting warp yarn S. Therefore, the dynamic stability of the printing rubber blanket surface can be ensured even under high-speed rotation of the printing press, so that the thickness of the compressed layer can be doubled. For this reason, such a compression layer P can impart excellent compressibility, cushioning and restoring properties to the printing rubber blanket, thereby expanding the physical properties of the printing material and the allowable range for its deviation. be able to.

Further, the compression layer P may be formed of a base cloth formed by using a weft having a multi-layered weft and a textured yarn. As such a base fabric, a weft double weave, a weft double weave with a core warp, or a fabric adopting a torsion structure with a core warp can be used.

FIG. 5 shows a structure diagram of a base fabric adopting a torsion structure with a cored yarn. In the figures, (a) shows the front design, (b) shows the back design, and (c) shows the weaving diagram with the core warp. The ground warp yarn H may be any spun yarn, but it is preferable to use a high-tensile chemical fiber for the core warp yarn W and use a bulky processed yarn for the front weft yarn F and the back weft yarn G. As is apparent from the weaving diagram with the core warp yarn shown in (c), the core warp yarn W is below all the weft yarns F, is above all the back weft yarns G, and intersects with the weft yarns F and the back weft yarns G. It will be woven in a straight line without any. In the weaving diagram with the core warp yarn (C), the composition ratio (H: W) of the ground warp yarn H and the core warp yarn W is set to 2: 1, but this composition ratio may be arbitrarily determined according to the purpose of use. Can be set.

In such a base fabric, a front weft yarn F and a back weft yarn G, which are bulky processed yarns, have a double-sided weft structure.
A large amount of weft yarn can be incorporated between unit areas to enhance compressibility. Innumerable bends inherent in bulky processed yarns have a fine solid spring structure, and together with a large amount of air, maintain the dynamic stability of the rubber surface layer that cannot be obtained with the conventional air spring structure, The effect excellent in the buffering / restoring property can be obtained. Further, since the high-strength chemical fiber yarn is used for the core warp yarn W, not only the base fabric is reinforced using the linearity, but also the stretching process of the main base fabric 4 can be omitted. Further, by adopting the double-break oblique text, the effect of preventing the printing rubber blanket from being twisted by the twill line (twill line) can be obtained. In addition, the compression layer P of the weft double weave using such a bulked yarn has a low cost while maintaining the performance substantially equal to that of the compression layer made of the base fabric employing the above-mentioned binding double weave. Therefore, it is possible to obtain a printing rubber blanket corresponding to a printing purpose at a relatively low cost.

The above-mentioned compression layer P is composed of a base fabric in which the above-described warp / weft-bonded multi-structured binding yarn is formed at a wavy inclination angle and the above-described weft-multi-structured weft yarn. It may be one obtained by laminating both a base fabric formed by using a lofty processed yarn. Further, a bubble-sealing gas spring thin film such as a sponge may be laminated on these base cloths.

When the printing rubber blanket of the present embodiment has the above-described compression layer P, the bulge phenomenon during printing can be effectively suppressed, and an appropriate printing pressure is secured. Therefore, clear printing can be performed.

The use of the printing rubber blanket of this embodiment has the following advantages in addition to the above.

The printing rubber blanket of this embodiment can be directly adhered or magnetically attached to a blanket cylinder of a printing press without using an underlay or packing. At this time, in the case of the conventional printing rubber blanket, the tension when wound around the cylinder is difficult to distribute evenly over the entire blanket, it is large at both ends, sometimes the blanket is hardened, the thickness is reduced, and the sponge layer is pressed. In contrast, the printing rubber blanket of the present embodiment is unlikely to be crushed or easily cut at the mounting groove angle during operation. In addition, the printing rubber blanket of the present embodiment can use an adhesive,
No mounting notch is required on the blanket cylinder side,
Since there is no need to use an underlay or packing in blanket loading and unloading, the blanket cylinder can be easily operated with a gentle rotation of the blanket cylinder, so that work can be rationalized and labor saved. Furthermore, if the blanket of this embodiment is used for a printing press, the contact rotation with other blanket cylinders becomes remarkably smooth, and vibrations, noises, and wear of the printing press can be reduced. The risk of giving is reduced. Furthermore, the loss of the blank portion of the printing paper due to the cutout groove on the blanket cylinder side can be omitted, and printing close to a continuous pattern can be performed with a web (rotary press).

Further, with the dimensional invariance of the printing rubber blanket, the improvement of the compression performance, and the expansion of the permissible range for various deviations, the conventional printing blanket of various types subdivided according to the printing purpose and the underlay are used. In contrast to the need for a material, in the case of this embodiment, a small variety can be used for various printing purposes.

[0032]

According to the rubber blanket for printing of the present invention, since the base fabric for rubber reinforcement is formed by using the above-mentioned yarn, it does not easily elongate even under a tensile load during printing.

Further, when the printing rubber blanket of the present invention is provided with the above-mentioned compression layer, the bulge phenomenon due to the printing pressure during printing hardly occurs, and at the same time, an appropriate printing pressure can be secured. Therefore, clear printing can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 2 is a view showing a base cloth (A) of a main base cloth adopted in the embodiment and details (B) of the main base cloth adopted in the embodiment.

FIG. 3 is a longitudinal sectional view of another embodiment.

FIG. 4 is a view for explaining a method of bonding a compression layer employed in the other embodiment.

FIG. 5 is a view showing a weft-double double-break oblique weaving structure with a core warp yarn among the compression layers employed in the other embodiment.

[Explanation of symbols]

 1 rubber surface layer 4 main base cloth P compression layer

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41N 10/02

Claims (2)

(57) [Claims] 1. A raw yarn comprising a rubber surface layer, a core made of long fibers obtained by cutting high-tensile chemical fibers to about 10 to 30 cm, and a yarn table made of short fibers covering the surface of the core. A rubber reinforcing base fabric laminated on the rubber surface layer, wherein the end of the core portion is entangled with the short fiber of the yarn surface and integrated with the raw yarn, and the blanket is a printing rubber blanket. 2. A compression layer disposed between the rubber surface layer and the rubber reinforcing base fabric, wherein the compression layer comprises (a) a warp yarn having a multi-layer warp / weft structure. The printing fabric according to claim 1, wherein the fabric is a laminate of one or both of a base fabric configured with a wavy slope and a base fabric configured by using a bulky processed yarn as a weft having a multi-weft multiple structure. Rubber blanket.