Overview
Ink decolorization testing machine is a special testing equipment that simulates the degree of decolorization of ink on the surface of printed products under friction. Its working principle is usually based on standardized friction motion, which evaluates the wear resistance of the ink adhesion layer through a specific pressure and number of frictions. The instrument plays a key role in quality control and R&D in the packaging and printing industry, and its test results are valuable for predicting the appearance retention ability of printed materials during transportation, handling, and daily use.
Technical principle
The core action unit of the device is usually a friction head that makes a reciprocating linear motion on a horizontal plane, with a surface covered with a standard friction material (such as white test paper or a specific fabric). The specimen is fixed on the test platform, and the friction head repeatedly rubs the specimen surface at a specified stroke and speed under the set pressure. After the test, the degree of decolorization is quantified by comparing the color change between the friction area of the specimen and the non-rubbed area, or by evaluating the amount of ink transferred to the friction material. The evaluation method can be quantitatively analyzed by using gray scale card or colorimeter according to the standard, and the calculation of color difference ΔE can refer to the following formula:
ΔE = √[(L₁ - L₂)² + (a₁ - a₂)² + (b₁ - b₂)²]
Among them, L, a, and b represent the coordinate values of the CIE Lab color space, and subscripts 1 and 2 represent the measured values of the samples before and after the test, respectively.
Specific applications in the packaging and printing industry
In the field of packaging and printing, the wear resistance of ink directly affects the shelf display effect and brand image of the end product. The application of ink decolorization testing machine runs through multiple links.
In the factory inspection of raw materials, printing companies can use this equipment to quickly screen the matching of printing materials (such as paper and film) and their surface treatment processes (such as varnishing and lamination) with ink, and evaluate the adhesion fastness of ink on different substrates.
In the production process optimization process, technicians can compare the test results of different types of inks (such as water-based inks, UV inks), different drying and curing conditions, or different printing process parameters, providing data support for selecting a more wear-resistant ink system and determining the optimal production process.
In the finished product quality verification process, for food packaging, daily chemical product packaging, book covers and other products that need to withstand frequent friction, decolorization test is an important step to verify whether it complies with internal enterprise standards or relevant industry standards, which helps reduce the risk of customer complaints and market returns.
Relevant test standards
A number of domestic and foreign standards organizations have formulated test methods for the abrasion resistance of printed materials, and these standards specify in detail the technical parameters, test conditions and evaluation procedures of the testing machine. Here are some common criteria:
| Standard system | Standard number and name |
| Chinese national standards | GB/T 7706 Lithographic decoration prints |
| Chinese national standards | GB/T 7705 Letterpress decoration prints |
| International standards | ISO 2834 Printing techniques Print preparation |
| American Society for Testing and Materials standards | ASTM D5264 Printed Abrasion Resistance Test |
| Japanese industrial standards | JIS K5701 Test Method for Printing Ink |
In practical applications, enterprises need to choose appropriate test standards according to the end use of the product and customer requirements. Test conditions such as pressure, frequency of friction, friction speed, friction material, etc. must be set strictly according to the standard to ensure the comparability and reproducibility of the test results.
Conclusion
As an effective quality control tool, the ink decolorization testing machine provides the packaging and printing industry with a means to quantitatively evaluate the abrasion resistance of inks. Through the scientific application of this equipment, enterprises can proactively identify potential risks and optimize materials and processes in the product development and production process, thereby improving the durability and overall quality of printed products and meeting the market's requirements for packaging appearance durability. As the industry's focus on sustainability and quality consistency deepens, the application of such standardized testing instruments will become more widespread.