color measurement before rewinding

Inline color measurement before rewinding

For contactless color measurement operation on the machine. The opacity of paper and board in color the stack and the opacity of paper and board are measured; for white grades also the optical brightener. The finished paper is measured directly before the reel. This ensures a very good correlation to the laboratory measurement results. The device works in a rough environment. Ambient light, web speed and web flutter have no influence on the measurement results.

Inline Closed Loop Color Control

An automatic Closed Loop Color Control one ensures constant quality. Even colour transitions can be run automatically. For the machine operators this means:

  • 100% control during the production process
  • Shorter transition periods
  • Avoidance of rejects
  • Saving of dyes or optical optical brightener

Advantages of the X-Rite Inline System:

  • X-Rite delivers a complete turnkey system
  • Installation of a color control system takes 3 days
  • A machine downtime of typically one hour is necessary
  • Extremely low maintenance costs

The colorimeter is mounted directly in front of the reel. The ERX50 is used to measure coloured paper (i.e. without opticaloptical brightener) and white paper and cardboard. Here the is measured optical brightener separately.

If there is no paper on the machine, the customized measuring frame (EFX) swivels the measuring device out of the web. As soon as the paper is listed again, the measuring device automatically swivels into measuring position and starts measuring.

Quality Control

The quality control software (ES15Win and ES18Win) controls the measuring device and displays the measured values clearly on the screen. Colored bars indicate the deviation of the produced paper from the target value. The machine operator can see at a glance whether his paper is too light or too dark, too red or too green, too yellow or too blue.

Closed Loop Color Control

The color control software (ES19Win) controls up to 3 ink pumps plus one brightener pump. This ensures a very constant quality even with fluctuations in raw materials. Even colour transitions can be run in automatic mode. This relieves the machine operator during this critical phase, he can take care of all the other settings.

The installation of the system normally takes two days for the color measurementcontrol, another day is needed for the control. A machine stop of only one hour is necessary. A connection to the control system is also possible.