JPH02248282A - Method for transferring thermal stencil printing base paper - Google Patents

Abstract

PURPOSE:To reduce not only the contact and friction surfaces of base paper and a transferring roller but also the charge formed in the roller and to prevent winding round trouble attracting the base paper by the surface charge of the roller by forming notch parts to the transferring roller of forming the roller from a conductive member or providing a destaticizing conductive brush. CONSTITUTION:Notch parts (stripe or verruca like shape) reducing the contact surfaces of a transferring roller and base paper and also reducing the quantity of the static charge accumulated in the roller are provided to the entire periphery of the roller. Or, the above mentioned roller is constituted of a conductive member to rapidly disperse formed charge to all of members and the local accumulation of static charge is prevented. Further, a conductive brush or roller brought into contact with base paper or the transferring roller to destaticize the same is provided to prevent trouble such that the base paper is wound around the transferring roller to make printing impossible even under such a condition that rubber roller or the base paper is easy to be charged because of low humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for transporting base paper in a thermal stencil printing machine.

[Prior art] A surface of a plastic film that is easily perforated by heating,
A digital stencil printing machine is used in which a base paper comprising an ink-permeable base material layer supporting the film is perforated by a thermal head, and the paper is wound around a printing drum to perform printing.

Conventionally, in this type of printing press, the base paper is supplied in a rolled state, is unwound while in contact with a transfer roller, is made into a plate by contact with a thermal head, and then is wound around a printing drum. This required a step of cutting the material to a fixed length.

In this case, in order to carry out each process, it is necessary to transport the base paper without any trouble, and for this purpose, rollers have been used that come into contact with the base paper and unwind and transport the base paper using frictional force.

On the other hand, since base paper for thermal stencil printing is made of plastic or a base material that is easily charged, there is a problem in that it is extremely easily charged and is likely to cause problems due to static electricity. Therefore, ordinary commercially available base paper takes measures to prevent static electricity, such as coating or adding antistatic agents, but these effects are incomplete and still cause many problems due to static electricity. .

[Problems to be Solved by the Invention] Among the static electricity problems that occur due to incomplete antistatic prevention of base paper, problems that occur frequently during printing press operation and are difficult to solve are problems caused by transfer during digital stencil printing machine operation. It is defective. This transport failure is a problem that often occurs especially during the dry winter season, and in many cases, the base paper gets wrapped around the feed roller, making it impossible for the process to proceed further.

Once the base paper gets wrapped around the rollers due to this problem, repair requires a lot of trouble, such as disassembling and reassembling the complicated machine, and after spending a lot of time to repair it, it has to be restarted. However, when the humidity in the room is particularly low, the same problem of wrapping occurs again and again.

An object of the present invention is to provide a method for transporting base paper without the above-mentioned transport troubles.

[Means for Solving the Problems] The present invention provides a method for reducing the contact surface between the transfer roller and the base paper when the base paper is transferred by contacting the transfer roller in a thermal stencil printing machine. Either the roller is provided with a notch, or the roller is made of a conductive material to prevent static charge from accumulating on the roller, or the roller or the surface of the base paper transferred in contact with the roller is free of static charge. This is a method of transporting base paper that includes a means such as providing a conductive brush or roller that contacts the base paper, the roller, or both to remove static electricity to prevent accumulation.

When providing a notch on the transfer roller, various patterns can be used to insert the notch, but in order to reduce the contact area as much as possible, the cutout should be at least 50% of the outer surface area of the roller.
, preferably by 80% or more.

The simplest way to make notches is to cut the entire circumference of the roller surface at regular intervals, leaving a thin contact area around the entire circumference. Alternatively, a method may be adopted in which the contact portions are left as wart-like protrusions that are independently distributed at regular intervals.

These notches are preferably made on rubber rollers that are normally used for transport. Next, when the roller is made of a conductive member, conductive rubber containing conductive fillers, conductive fibers, etc. as a constituent material may be used.

It is best to use a conductive roller as grounded as possible.

It is also a good method to provide the above-mentioned notches in the conductive roller.

Next, when static electricity is removed by contacting the base paper, the roller, or both, a conductive brush made of metal, carbon thread, or conductive fiber, or a roller made of conductive rubber or conductive metal is used. It is best to ground these brushes and rollers.

[Operation] Providing a cutout to reduce the contact area between the transfer roller and the base paper reduces the probability of contact and friction between the base paper and the roller, reducing the amount of static charge that accumulates on the roller. it is conceivable that.

It is also considered that by providing the notches in the roller, a surface with a relatively large curvature is formed on the roller surface, and static electricity on the surface with a large curvature is relatively easily discharged into the air and dissipated.

Furthermore, even if the roller surface has an equal amount of charge, a roller with a notch has a large distance between the base paper and the surface of the notch, so the electrostatic force attracts the base paper. It is also possible that the rollers are smaller and less likely to have trouble getting wrapped around the rollers.

Furthermore, if the roller is made of a conductive member, all locally generated charges are quickly dispersed into the shrine, preventing local static charge from accumulating. Especially when the conductive member is grounded, Since the potential can be brought to zero quickly, it is thought that the electric charge on the surface of the roller will attract the base paper and prevent it from causing problems with wrapping.In addition, conductive brushes or rollers for weight removal may be provided to remove the base paper or the transfer roller or When removing static electricity from both,
Similarly, the base paper is attracted to the roller due to static electricity,
It is thought that this prevents the occurrence of wrapping problems.

[Example] The present invention will be specifically explained below with reference to Examples.

Example 1 A base paper roll for the printing machine was set in a commercially available digital stencil printing machine, and stencil printing was attempted at 23° C. and relative humidity of 15%.

The printing machine is configured to transport the base paper using rubber pinch rollers, but under these low humidity conditions, problems often occurred where the base paper would become wrapped around the rubber rollers, making it impossible to transport the paper.

Therefore, the roller was removed, and 9 mm notches were provided over the entire circumference at a pitch of 10 mm, leaving a width of contact portion 1+n. This reduces the contact area of the roller to 90%.
This means that it has been reduced.

When a rubber roller having this cutout was set and an attempt was made to perform plate making printing, plate making printing could be performed without any trouble under the same conditions.

Example 2 In Example 1, instead of providing a notch in the transfer roller, a static elimination brush made of carbon fiber was grounded and attached at a position where it would slide on the transfer rubber roller.

As in Example 1, plate making and printing became possible under the same conditions without any trouble.

Example 3 In Example 1, instead of notching the transfer roller, the rubber of the roller was replaced with a roller made of conductive rubber, and the roller was grounded.

Plate making and printing became possible under the same conditions as in Example 1 without causing any problems with wrapping.

[Effects of the Invention] According to the method of the present invention, even under conditions where the humidity is low and the rubber rollers and the base paper are easily charged, the base paper can be smoothly transported without causing problems such as the base paper wrapping around the transport roller and making it impossible to print. be able to.

Claims (1)

[Claims] 1. When the base paper is transferred in contact with the transfer roller in a thermal stencil printing machine, the roller is provided with a notch to reduce the contact surface between the transfer roller and the base paper, or the roller is Either the roller is made of a conductive material to prevent static charge from accumulating on the roller, or the base paper or the roller, or both, are contacted to prevent static charge from accumulating on the roller or the surface of the base paper transferred in contact with the roller. A method for transporting base paper that includes an additional means such as providing a conductive brush or roller to remove static electricity.