ARTJET UV Printer Application 5 Sai rip print size compensation
ARTJET UV Printer has been sold in Korea for 4 years, and we are organizing the printer problems we have encountered so far, their causes, and their solutions.
We have compiled 10 different print head problems and 17 ink supply problems, and you can find detailed information at the site below.
ARTJET UV Printer troubleshooting sum up
From last time, we are explaining not only UV printer problems and solutions, but also what products are produced with UV printers.
In the first session, we explained how to print high-value Braille using the ARTJET UV Printer. For more details, please refer to the site below.
ARTJET UV Printer Application 1 braille printing
In the second session, we explained how to align the images on the front and back when flipping the material over and printing a different image on the back after printing on the front. See below for details.
ARTJET UV Printer Application 2 Flip the material and align it
In the third session, we explained how to print a three-dimensional elephant rather than simply printing it in color as shown below.
ARTJET UV Printer Application 3 2.5D UV print
ARTJET UV Printer Application 3_1
In the fourth session, I explained how to implement colors that are not expressed in colors created with an ICC profile using the Sai rip [Color Adjustment] tab.
ARTJET UV Printer Application 4 Sai rip color graph
Today, I will explain how to accurately match the print size using Sai rip.
“The Ai file size is 500 x 600mm, but when actually printed, the X-axis 500 is almost correct. But the Y axis is 598mm, not 600mm. “What should I do?”
UV Application that can be produced with a UV Printer are important, but I explain this because it is essential to properly produce the UV printing item.
I.“Why is the file size and actual print size different?”
1. Mechanical error
The difference between the image file size and the actual printed image size is almost always due to mechanical errors.
Inkjet, which prints images by firing ink back and forth between the X and Y axes, moves based on the position values of the X and Y axes.
But,
There is a deviation in the motor itself that moves the X and Y axes,
The belt connected to the motor also has different tension for each section, so there is also an tolerance.
Linear scale with resolution of 10um or 5um and application of linear motor, metal and urethane belt test.
While conducting all tests, I measured the commanded travel distance and the actual distance moved using precision laser measuring equipment, and found that there was a difference of 100um in some places.
At last,
The mechanical movement does not travel the exact distance as commanded, as we thought.
As errors accumulate, the error range gradually increases when printing large sizes in the Y-axis direction.
2. Default size correction function in Rip Software
In the early days, almost all inkjet printers used the roll-to-roll method to print large-sized images, such as banners.
The conveyor belt type or roll to roll method inevitably results in greater positional error in the Y-axis direction than the flat plate method.
The feed value changes depending on the material thickness,
If slip occurs in the material, the position value is also distorted.
The method of transferring material through rolls also has processing errors in the roll itself.
To correct these positional errors, Rip software is equipped with a size correction function as standard.
At my workplace in 2006, Wasachi rips were used for a time, and I remember the American person in charge of training explaining size correction.
II. How size correction works in Rip software
It’s very simple.
Since there are differences in how each Rip software company adjusts it, let me first explain how it works:
* If the flat size is 1 x 1 meter or 2.5 x 1.2 meters, create a 2.5 x 1.2 meter square image (Ai file) and proceed with actual printing.
* The size correction method is the same for the X and Y axes. To explain based on the Y axis,
* Let’s assume that the Y-axis length in the Ai file is 1200mm, and the actual printed Y-axis size measured with a tape measure is 1195mm.
– The option window for size correction in the Rip is set to the default value (1 or 100). There are separate X and Y axes, and here we will use 1.
– I printed out 1200mm, but it came out as 1195mm.
=> 1200: 1195 = 1: X
=> X = (1195×1)/1200
=> X=0.99583333……
If you enter this value as 0.99533 instead of 1 in the size correction option window and print it again, the size will be corrected to 1200mm instead of 1195mm.
III.Run it with Sai Rip software
1. Go to size correction options window
Execution- size compensation
size compensation window
2. Description of size compensation window
There are two methods.
No.1 method marked in yellow
It’s easy, but the options window lacks detail.
The file print size is 300 (width) x 300 (length) mm, and after actual printing, if you enter the measured size, the correction factor will automatically change.
This completes the size correction.
However, the ARTJET UV Printer print size is 600 x 899mm.
After printing a 300
If you use this value, tolerance that were not visible at 300mm may occur when printing 600mm on the X-axis (width) or 899mm on the Y-axis (length).
No.2 method marked in red
Without using the test print of No.1,
After making the image size arbitrarily large and measuring the size of the actual printed image with a ruler,
The method is to calculate that value and directly insert it into the correction factor.
Although it is a little cumbersome, I recommend this method.
3. Practice
Make the Ai file size 600 x 899mm and print it with ARTJET UV Printer.
After printing is complete, measure the actual printed size using a ruler.
For example, let’s assume that the X-axis (width) is accurate at 600mm, and the Y-axis (length) is 895mm.
When the correction factor value is 1.00000, the actual printed size of an 899mm image file is 895mm, so the following equation is established.
899mm : 895mm = 1.00000 : X
899mm x X = 895mm x 1.00000
X= (895mm x 1.00000) / 899mm
X = 0.99555
Size correction is completed by entering the value 0.99555 in the correction factor and length section.
And save !!
4. How to do it when you want to increase it by 0.2mm
If you watch the YouTube below, it explains in more detail how to increase and decrease the size.
https://www.youtube.com/watch?v=XUPhv9I3CWc&t=167s
IV. It won’t be a big problem
In the case of a large UV printer, the print size is large, and if size correction is not performed, the size varies greatly.
For this reason, people who use large-sized UV printers know that this function exists, and sometimes run it themselves.
In the case of small UV printers, the print size is not large, so users do not pay much attention to it and the size error is not actually large.
However, sometimes when printing in large sizes, you find that the size does not fit.
At this time, you can perform size correction.
Although the test has not been conducted yet, when crop mark cutting is performed with a laser cutting machine,
If it is biased to one side, there may be room for improvement by performing size correction.
That’s it for today.