NEWLONG SEIMITSU KOGYO CO.,LTD.

　

In screen printing, there is "bleeding" as a troublesome defect.
This is a phenomenon in which the complicated pattern gradually becomes thicker as it is being printed.
This is very difficult when printing fine patterns.
For example, the dots on the candy cane for the Chinese character "den".

Every electronic product has a power source.
Looking at the character "den", I feel resentful why the Japanese word is "den".
English is good "POWER"...

However, this is less likely to happen with other printing methods.
For example, complex characters such as "Hanko" can be stamped easily without bleeding.
What is the difference? This is a feature of screen printing
like a fate that we shouldered as a flip side of the nature of being able to do "thick film printing".

Other printing methods deposit a minimal amount of ink on the plate and transfer it to the substrate.
Due to the printing method, the amount of ink that can be transferred is small, and the film thickness that can be printed is thin.
Therefore, the ink rarely protrudes from the pattern, so bleeding is less likely to occur.

On the other hand, in screen printing, from the opening of the screen plate
A large amount of ink is supplied by the squeegee, resulting in a thicker print film.
However, this causes the ink to protrude from the printed pattern and cause bleeding.

 

By the way, the method to prevent bleeding in screen printing is based on the following things.

 

1. Remove the plate from the substrate as soon as possible after the ink has transferred to the substrate so that the plate is not smudged by bleeding.
(Also known as release)

2. Clean the plates regularly.

3. Adjust ink properties.

 

We have proposed various printing machines for 1. and 2.
However, there were pros and cons for symptomatic treatment.

However, the situation is a little different with the Rotary Screen-printer that we put on the market a few years ago.
No bleeding at all.
On the contrary, even if the plate is intentionally soiled during printing to cause bleeding, the bleeding will naturally disappear.
With conventional lithography, once bleeding occurs, it cannot be resolved naturally.
I think that 1. is working well as the cause of this.

In rotary screen printing, both the plate and the printing table are cylindrical.
This means that plate and table are in constant contact.
In addition, since printing is performed while rotating in opposite directions, the plate and the material to be printed are separated at the same time as the ink is transferred.
Unlike lithographic plates, there is no delay in plate release.
Therefore, the plate will not be stained by the transferred ink.

Next, when the plate is intentionally soiled, the attached ink
It adheres to the substrates to be printed that are fed one after another and is wiped off.
And since new ink is not supplied, it adheres to the plate.
Bleeding disappears when all the ink is removed by the substrate.

Printing without bleeding is very easy to do.
Defects will not occur if only the adherence of foreign matter is confirmed afterwards.
To deal with foreign matter, if environmental measures are taken around the printing press,
It is possible to raise the yield to the limit because it is possible to control a considerable part.

In the results of printing experiments at our Muikamachi factory,
A yield of 99% or more has been achieved under a general air-conditioned atmosphere.
95% of the same thing is printed using the conventional method.
It can be seen that this is a printing method with a very good yield.

Rotary screen printing is a smear-free screen printing method.