Testing Methods For Printing Inks

Testing methods for printing inks encompass compositional analysis, physical property testing, and assessments of chemical safety and environmental performance. Compositional analysis may employ Fourier Transform Infrared (FTIR) spectrophotometry to identify major constituents-such as solvents, pigments, plasticizers, and film-forming agents-and to determine their mass fractions. Physical property testing involves several parameters: surface tension is measured in accordance with ISO 304; viscosity is determined using a rotational viscometer following ASTM D2196; pH and conductivity are measured based on GB/T 9725; and contact angle and wettability are evaluated using a contact angle goniometer.
Testing for chemical safety and environmental performance is conducted in accordance with relevant standards for eco-labeled products. Parameters include the content of volatile organic compounds (VOCs) and heavy metals (such as lead, mercury, cadmium, nickel, and hexavalent chromium), as well as limits on hazardous substances like ammonia and its compounds, methanol, formaldehyde, and phenol. Relevant testing standards include international standards (e.g., ISO 304, ASTM D1331) and national standards (e.g., GB/T 13217.5, HJ/T 371-2007). Commonly used testing equipment includes surface tensiometers, rotational viscometers, and ICP emission spectrometers; testing may be performed by third-party institutions holding CMA or CNAS accreditation.