W49 | W71 – Leaflet | Print Gloss
Print Gloss
AMSTERDAM - Multi-purpose printability tester
Version: 2022-11
Introduction
When ink is printed on paper a part of the ink is absorbed. If the ink is absorbed either too slow or too fast, it may result in a change of the dry ink properties. When absorption is fast, this may result in a reduction of e.g. printing gloss. For the offset printing process this property is very important.
The following listing shows the different methods, dependent to the roughness of the paper used:
W49-AMS - rubber 85 Shore A for very smooth papers.
W71-AMS - rubber 65 Shore A for very smooth or rough papers.
To test inks, the method can be executed in the same way, but instead of a test ink, the ink to be tested is used together with the standard coated paper C2846.
W49-AMS - rubber 85 Shore A for very smooth papers.
W71-AMS - rubber 65 Shore A for very smooth or rough papers.
To test inks, the method can be executed in the same way, but instead of a test ink, the ink to be tested is used together with the standard coated paper C2846.
Principle
A paper strip to be tested is printed with a standard gloss ink with the Amsterdam printability tester. After the ink has dried completely, the gloss is measured.
Method of operation
Materials
- [402.634.720] Printing disc, black rubber, 50 mm, 85 Shore
- [402.687.720] Printing disc, black rubber, 50 mm, 85 Shore
- [404.009.029] Strips of reference paper, 55 mm, IGT code C2846 (for testing ink only)
- [466.000.710] IGT High Speed Inking Unit (HSIU)
- [466.003.003] Top roller, 4 segments for conventional inks
- [408.000.200] IGT ink pipette 0,01 ml resolution
- [404.380.010] IGT Red Brilliant Standard
- [555.000.060] IGT Gloss meter G60 or
- [555.000.075] IGT Gloss meter G75 or
- [555.000.268] IGT Gloss meter G3 (G20-60-85)
- Strips of paper to be tested, preferable 55 x 340 mm², 3 strips per sample
- Lint free rags
- cleaning naphtha and ethanol
Testing conditions
Standard test atmosphere according to ISO 187 (23,0 ± 1,0 °C and 50 ± 2% RH)
SAMPLE CONDITIONING
Be aware of the fact that a different way of conditioning of the samples can have influence on the results.
Standard settings
AMSTERDAM – MULTI-PURPOSE PRINTABILITY TESTER
- Printing speed: constant 0,2 m/s
- Printing force: 625 N
- Ink film thickness 2,4 µm or 4,8 µm (for less smooth papers)
IGT HIGH SPEED INKING UNIT (HSIU)
- Water bath: 23 °C (73,4 °F)
- Mode 2:
- Start-up time [10 s]
- Distribution time 1 [20 s] | Distribution speed 1 [0,5 m/s]
- Inking time discs [15 s]
Preparation
- Cut paper strips of 55 x 340 and mark with top and/or bottom side, machine and/or cross direction and a code for the paper.
- Select the method Print Gloss.
- Fill the ink pipette with the ink to be used.
- Set the HSIU in Mode 2.
- Apply 0,10 ml (or 0,21 ml for less smooth papers) of ink to a segment of the top roller and distribute the ink.
- Place the printing disc on the shaft of the HSIU and ink the printing disc.
Execution
Mount a strip of paper or board to be tested on the sector.- Touch the button [PRINT] to rotate the sector and the 1st printing shaft into the start position.
- Press both side buttons to make a print.
- Release the side buttons when done.
- Remove the printed strip from the sector.
- Clean the rollers of the inking unit or use a clean segment for the next test.
- Touch [BACK] and start up a new test. It is recommended to perform the test at least three times.
Mount a strip of paper or board to be tested on the sector.Store the printed strips in the standard atmosphere at a safe place so that it cannot be damaged for at least 24 hours.
Cleaning
- Clean the rubber printing disc with lint-free rags and cleaning naphtha.
- Clean all rollers of the inking unit, including the metal ones with lint-free rags and cleaning naphtha.
Assessment
- Measure the gloss on the dried ink of the printed sample with a gloss meter on every strip.
- Calculate the average and if desired, the standard deviation.
NOTES
- Due to drying of the ink, it is not advised to add some ink to the same segment of the inking unit after a test. Clean the used segment first or choose the next segment of the top roller.
- IGT Red brilliant Standard test ink has a shelf stock time <1 year, open time <6 months.
Randstad 22 - 02
1316 BX Almere
The Netherlands
P.O.box 22022
1302 CA Almere
The Netherlands
