Printing Quality Assurance

Recently, printing industries have been facing a revolutionary hallenge in digital processing, in order to meet clients’ different needs, such as enquiring small quantity but of large variety, closing deals as quickly as possible, and undergoing compressed working time. Having to face such strict conditions, emphasis put on the printing quality is thus very crucial.

In order to minimize the errors caused by macrography and experienced head staff, it’s been years that the printing industries use scientific tools to test printing quality. However, these tools are not only costly, but also too heavy to be taken out of the laboratory and to be applied in the real production line. With the microphotography development background, our company, Lumos Technology Co., Ltd., has combined Canon’s optical technology to develop a portable microscope, the X-Loupe Portable Microscope Camera, with 60, 150, and 300 magnifications and 8 million pixels of resolution.

With this advanced development, we provide not only an efficient inspection intrument for the printing process, but also an auxiliary observing tool for the printing related R&D departments, the laboratories and the production line. The excellent optical rendering capacity and large view finder can minimize eye fatigue under long working hours, reduce time for decision making and increase accuracy, so that the work can be more efficient and the process can be reduced.

In addition, with the mobility and portability of the X-Loupe, staff is able to directly photograph samples in the production line. The X-Loupe can help cut down the spot-check procedure, and can be used by the sales representatives as a convenient tool to show and discuss the printing matter with the clients.

Applying the X-Loupe to test printing processes

To test raw materials under microscope:

  1. Examine the fineness of grind.
  2. Examine the surface physical property of the raw material.
  3. Examine the surface chemical property of the raw material.
  4. Examine the coating hardness of the raw material.
  5. Examine the surface tension of the plastic raw material.

To test semi-finished products under microscope:

  1. Examine the rub resistance of surface.
  2. Examine the adhesive force.
  3. Examine the level of dryness.
  4. Examine the printing dots.
  5. Examine the printing color control strip.
  6. Examine the strip of 3D lenticular print.

To test finished products under microscope:

  1. Examine the rub resistance of surface.
  2. Examine the adhesive force.
  3. Examine the printing dots.
  4. Examine the printing color control strip.
Illustration: Micro-observation of rub resistance after the test
(Photographed with the X-Loupe G20, 150X)

The X-Loupe is able to obtain the actual test data as follows:

It can at least observe 0.5% and 99.5% tiny dots of plate control wedge on the printing plate and 0.01mm to 0.02mm dots on the printed material. It can also be combined with various printing testers, such as rubbing resistance tester, grind gauge…etc. to assist the micro-measurement of the tested materials and products.

Also by combining with the digital microscope and image processing software, more precise dot area of 0% and 100% can be obtained.

The X-Loupe can observe whether the color overlay is within allowable error of ±0.1mm. Combining with a protractor, it can evaluate the angle of the outlets to avoid apparent moiré pattern. For example, the allowable error for black screen is 45 degrees, 75 degrees for magenta screen, and 15 degrees for blue screen. In addition, it can also calculate the screen ruling.