Definition
Gravure ink color spreader is a special experimental testing instrument used to simulate the gravure printing process and quantitatively evaluate the color performance and transfer characteristics of ink. It provides key data support for ink color matching, quality control, and printability research by uniformly coating gravure ink on specific substrates under standard conditions to form measurable color samples.
Principle
The core working principle of the instrument is to accurately simulate the ink transfer mechanism of gravure printing. It mainly uses a gravure roller or scraper system with a standard depth and number of lines to evenly scrape the measured ink onto the surface of the substrate. The process is carried out at a controlled pressure and speed, ensuring that the ink spreads and forms a uniform film that approximates the actual print. Subsequently, the formed color sample is collected and analyzed by colorimeter or spectrophotometer under the standard light source environment, so as to obtain objective parameters such as chromaticity value, density, and hue.
Measurement method
Standard measurement processes typically follow relevant industry standards. First, the gravure ink to be tested is placed in the ink storage part of the instrument. Then, a specific substrate (e.g. coated paper or plastic film with a specific weight of a certain weight) is selected to be fixed on the coating platform. Then, start the instrument so that the gravure roller or scraping system completes the application at a set speed and pressure, forming a flat, uniform ink layer. The color samples made need to be dried under the specified temperature and humidity conditions. Finally, using calibrated color measurement equipment, under standard lighting and observation conditions, multi-point measurement is carried out on the designated area of the dry color sample, and the average value is taken to obtain reliable chromaticity data, such as L*a*b* value, color aberration ΔE, ink strength, etc.
Influencing factors
The accuracy of the measurement results is influenced by several factors. Instrument factors include the depth and shape of the gravure roller, the stability of coating speed and pressure, and the accuracy and wear state of the scraper. The properties of the ink itself, such as viscosity, thixotropy, and drying speed, can directly affect the uniformity of the ink layer and the final color. The surface energy, smoothness and ink absorption of the substrate material are also key variables. Environmental conditions, particularly ambient temperature and relative humidity, can affect the leveling and drying process of inks. In addition, the standardization of the operation process, such as the amount of ink sampling, the drying time and conditions of the color sample after coating, and the calibration status of the color measurement instrument, all need to be strictly controlled.
Applications
Gravure ink spreader is widely used in R&D and quality control links in packaging printing, publishing printing and special printing and other related industries. In ink manufacturing, it is used for color development of new formulations, batch-to-batch color consistency control, and evaluation of pigment strength. In printing enterprises, it is used for ink color pre-inspection before going on the machine to reduce material waste during start-up and debugging. In addition, the instrument also serves third-party testing institutions to provide objective ink color performance evaluation reports for both supply and demand sides, and is applied to the verification of relevant industry standards.
Selection considerations
When choosing a gravure ink color spreader, it is necessary to comprehensively consider multiple technical parameters and actual needs. The coating accuracy and repeatability of the instrument are the core indicators, which are directly related to the reliability of the data. It is necessary to confirm whether it is compatible with the types and widths of substrates commonly used in the target industry. Examine whether it has the ability to simulate different printing conditions, such as pressure and speed adjustment ranges. The durability of the instrument structure and the standardization and replaceability of key components (such as gravure rollers, scrapers) also need to be paid attention to. Additionally, consider its compatibility with existing color measurement systems in your lab, as well as whether the operational process complies with or facilitates the implementation of relevant international, national, or industry standards. The completeness of the after-sales service and technical support network is also a factor to ensure the long-term stable operation of the instrument.