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W56- Leaflet | Toner Adhesion IGT

Toner Adhesion IGT
AMSTERDAM - Multi-purpose printability tester
Version: 2023-06

Introduction

Laser printing is an electrostatic digital printing process. It produces high-quality images by repeatedly passing a laser beam back and forth over a negatively charged cylinder (drum). This drum then selectively collects electrically charged powdered ink (toner), and transfers the image to the paper, which is then heated to permanently fuse the image to the paper. The degree of toner adhesion is effected by printer, toner and paper. The determine the degree of adhesion characteristics of the paper a print with pick oil can be made.
In leaflet W55 the method has been described for a constant speed of 0,4 m/s, according to EN 12883. When the toner is not pulled off from the paper the test can be carried out at higher constant speed.

In leaflet W56 the toner adhesion is determined at increased speed.

Principle

The paper is laser printed/photocopied. A strip of this toner printed paper is printed with pick test oil at an increasing speed on an IGT printability tester. After printing the densities are measured at several areas where the print has been made with pick test oil (toner has been pulled off) at a different speed and at the areas where no print has been made with the pick test oil (toner has not been pulled off). The densities are used in a formula to calculate the percentage of toner, which has been pulled off from the surface of the paper at the different speeds.

Toner adhesion at an increasing speed, print
Toner Adhesion at an increasing speed, print

Method of operation

Toner Adhesion at an increasing speed, print

Materials

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: increasing, end speed at choice
  • Printing force: 800 N
  • Camera lamp high (Not applicable for Amsterdam Basic type)
  • Checkbox Scan activated (Not applicable for Amsterdam Basic type)

IGT High Speed Inking Unit 4 (HSIU)

  • Water bath: 23,0 °C (73,4 °F)
  • Mode 3:
    • Startup time [5 s]
    • Distribution time 1 [30 s] | Distribution speed 1 [0,5 m/s]
    • Distribution time 2 [10 s] | Distribution speed 2 [0,2 m/s]
    • Inking time discs [20 s]

Preparation

  1. Print a stack of 10 sheets of standard paper, then 5 sheets of the paper to be tested, then another 5 sheets of standard paper at maximum density on a laser printer or copier.
  2. Condition the papers during >6 hours in the standard atmosphere.
  3. Cut the paper strips (preferable 55 x 297 mm), 5 strips per sample and mark them with top and/or bottom side, machine and/or cross direction and a code for the paper.
  4. Select method Toner Adhesion IGT.
  5. If desired, touch the checkbox Scan to scan and save (not applicable for Basic type Amsterdam)
  6. Mount the paper packing on the sector.
  7. Fill the ink pipette with the desired IGT pick test oil.
  8. Set the HSIU in Mode 3 (for changing settings and oil application, refer to your HSIU manual).
  9. Apply 0,3 ml of pick test oil to the inking unit or add 0,03 ml of pick test oil to maintain this layer and distribute the pick test oil.
    • NOTE: Do not add pick test oil more than 4 times.
    • NOTE: For another type of top roller see the manual of the inking unit.
  10. Place the printing disc on the shaft of the HSIU and ink the printing disc.

Execution

  1. Mount a strip of paper to be tested on the sector.
  2. Take the printing disc from the inking unit and place it on the 1st printing disc shaft of the tester.
  3. Touch the button [Print] en press both side buttons to make a print and, if present and activated, to make a scan.
  4. Release side buttons when the display says DONE.
  5. If the camera was activated, save or discard the results.
  6. Take the sample from the sector.
  7. Before starting a new test, clean the disc and the used segment of the inking unit (or use the next segment or add 0,03 ml of oil to the segment used) and start inking the disc again.
  8. Perform the test at least 10 times per sample for standard paper, then 5 times per sample for paper to be tested and after that
    5 times per sample for standard paper again.
  9. After finishing all tests, press [Back] and clean and store all parts.

Cleaning

  1. Clean the disc with lint-free rags and cleaning naphtha.
  2. Clean all rollers of the inking unit, including the metal ones with lint-free rags and cleaning naphtha.
  3. Make sure the Amsterdam is clean and if necessary dry with some ethanol on a lint free rag.

Assessment

If a scan was made

The print is scanned and shown in the display.

Toner Adhesion, test result

Magnification of the scan via touch screen is possible.
Touch the textbox [Batch] on the left of the display, fill in the information and push [OK]. To save both data and image push [OK] again. Afterwards the data and images can be transferred to a USB stick. For the correct procedure please refer to the manual of the Amsterdam.
Data are saved in a CSV format that can be loaded into Excel. Images are saved as PNG files. The data will relate the results to a specific image to enable you to combine both.
Scan is saved as black and white image, these are only to be used for illustrative reasons.

 

Ruler on test strip
  1. Mark points on the test strip after 40, 60, 80, 100, 120, 160 and 180 mm from the beginning of the print or place the ruler on the strip with the beginning of the ruler at the beginning of the print (= the centre of the initial print contact line) and the coves on the print.
  2. Measure the densities on the toner which has not been subjected to the pick test (D solid black) and on the toner which has been subjected to the pick test (D IGT) at the locations as mentioned in point 1. Measurements have to be made 10 times on every single strip.
  3. Calculate the toner adhesion as:
                                                             Toner adhesion = (D IGT : D solid black ) x 100%
    In which:
    D IGT = density of toner which has been subjected to the pick test
    D solid black = density of toner which has not been subjected to the pick test
  4. If desired make a graph of the test results.
  5. Repeat the points 1 thru 4 for every test strip.
  6. Calculate the average and if desired the standard deviation. Sometimes it can be useful to mention the highest and lowest values as well.

NOTES

  1. Pick test oils have a shelf stock time: <3 years; open time: <1 year.

Randstad 22 - 02

1316 BX Almere

The Netherlands

P.O.box 22022

1302 CA Almere

The Netherlands

+31 20 40 99 300 +31 20 40 99 339 info@igt.nl
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