The Coating Distinctness of Image (DOI) Tester is an optical instrument used to quantitatively assess the imaging clarity of coating surfaces. It measures the ratio of specular reflection to diffuse reflection by analyzing the reflected image of a standard pattern on the coating, thereby obtaining an objective DOI value. This instrument is widely used in industries such as automotive and furniture to monitor coating processes and improve the appearance quality of products. When in use, it should be combined with other indicators, such as glossiness, to comprehensively evaluate coating performance.
2026-04-03
This article introduces the standardized application of visual color comparison boxes in ink color evaluation. It emphasizes that to ensure the accuracy and consistency of color judgments, the evaluation environment must be strictly controlled. The core principles involve using standardized light sources (such as D65), maintaining a neutral gray background, and fixing the observation angle (e.g., 0°/45°). Additionally, operational procedures must be standardized, including preheating the light source, allowing for visual adaptation, and isolating external light. These measures collectively reduce environmental interference, making evaluation results comparable across different personnel and conditions, thereby providing a reliable foundation for color quality control in the ink industry.
2026-04-03
Pearlescent coatings, due to the inclusion of special flaky pigments, produce a color effect that changes with the viewing angle, known as "goniochromism." Traditional single-angle measurements are insufficient for accurately capturing this characteristic. Multi-angle colorimeters quantify color differences, lightness, and chroma variations between different angles by simultaneously measuring color data from multiple fixed angles (e.g., 15°, 45°, and 75°), thereby providing a comprehensive assessment of the coating's color performance. This technology offers an objective and precise detection method for the research, development, production, and quality control of pearlescent coatings.
2026-04-03
The hiding power tester is a professional device used to evaluate the covering ability of coatings. It quantifies the hiding effect by measuring the reflectance ratio (contrast ratio) of the coating film on black-and-white substrates. The test follows international standards, using a precision applicator to control the coating amount, and measurements are taken after drying under standard conditions. The core components of the instrument include a light source, an optical probe, and sensors to ensure data accuracy. It is widely used in the coatings industry to help optimize formulations and monitor quality, providing a scientific basis for product development.
2026-04-03
The whiteness meter simulates the human eye's perception of white by measuring the diffuse reflectance of light, particularly in the blue light spectrum, from paint samples and converting it into a quantifiable whiteness value. It employs standard optical structures and mathematical models, such as the Ganz formula, to evaluate the lightness and chromaticity of paints. In the coatings industry, whiteness meters are used for research and development, production quality control, and weathering tests, helping to optimize formulations and ensure product consistency. Strict adherence to standard operating procedures, control of sample conditions, and measurement conditions are essential to ensure the accuracy and comparability of the data.
2026-04-03
A reflection densitometer measures the light reflectance of the ink layer, converting it into density values to objectively reflect the thickness and concentration of the ink layer. In printing, it is used to monitor solid density, ensuring stable ink supply, replacing subjective judgment, and achieving data-driven control. Additionally, it supports standardized production by maintaining color consistency through comparison with target values, and provides the basis for calculating quality parameters such as dot gain and print contrast. Proper use requires standardized calibration, selection of color patches, environmental control, and integration with colorimetric measurements for more comprehensive color management. This tool enhances the controllability and quality stability of the printing process.
2026-04-03
Haze is a phenomenon in high-gloss coating surfaces where light scattering causes the blurring of reflected images, reducing visual clarity. A haze meter quantifies the haze value by measuring the intensity ratio of specularly reflected light to scattered light at specific small angles, with lower values indicating a clearer surface. Testing must follow standard procedures, paying attention to calibration, sample preparation, and environmental control. Industry standards such as ASTM and ISO provide the framework for testing. The haze value is influenced by material properties, processing techniques, and measurement conditions. It is widely used in industries such as automotive and electronics to monitor the appearance quality of coatings.
2026-04-03
This article introduces a method for evaluating coatings with different gloss levels using a three-angle gloss meter. Gloss is defined as the ratio of reflected light to incident light on a surface, and the instrument quantifies this by measuring specular reflection at three angles: 20°, 60°, and 85°. Five coating samples were selected and measured under standard environmental conditions. The results show that high-gloss coatings exhibit higher values at a 20° angle, while matte coatings show higher values at an 85° angle, indicating that multi-angle measurements provide a more comprehensive reflection of coating characteristics. During measurement, attention must be paid to surface cleanliness, environmental stability, and instrument calibration to ensure accurate results.
2026-04-03
This article introduces the method of measuring the surface gloss of ink using a gloss meter. Gloss is a key indicator of the visual quality of ink, and the instrument quantifies gloss by measuring reflected light at specific angles. The article explains the measurement principle, how to select the appropriate angle (e.g., 20°, 60°, or 85°) based on the gloss range, and provides a detailed list of steps for sample preparation, calibration, and measurement. It also emphasizes factors that affect the results, such as surface flatness, ink film thickness, and drying degree, which need to be controlled during operation to ensure accurate and reliable measurements.
2026-04-03
This article discusses the role of colorimeters in controlling color consistency in paint production. Since human perception of color is easily influenced by lighting and subjective factors, colorimeters provide an objective basis for production by measuring spectral data and quantifying color differences in the CIELAB color space. The article points out that colorimeters should be used for monitoring in raw material inspection, production processes, and finished product testing, and that unified measurement standards and reasonable color difference tolerance ranges should be established. Additionally, it emphasizes the importance of instrument calibration, standardized sample preparation, and proper operation to ensure data accuracy. Overall, the application of colorimeters helps paint companies achieve stable color quality and reduce the occurrence of issues.
2026-04-03
This article introduces the use of high-performance liquid chromatography (HPLC) to detect additives in ink. Ink additives, such as photoinitiators and antioxidants, affect its performance and safety, making accurate detection crucial. HPLC technology analyzes samples by separating their components and is particularly suitable for medium to non-polar compounds in ink. Prior to detection, ink samples require pretreatment such as solvent extraction and purification. Method optimization includes selecting the appropriate chromatographic column, gradient elution of the mobile phase, and detector compatibility. During analysis, qualitative identification is achieved by comparing with standards, while quantitative analysis is performed using standard curves. The article also highlights challenges such as matrix interference and co-elution, which can be addressed by optimizing purification steps or coupling with mass spectrometry. This method provides reliable support for ink quality control and safety assessment.
2026-04-03
This paper introduces a method for determining heavy metal content such as lead, cadmium, chromium, and mercury in coatings using atomic absorption spectrometry. The method is based on the absorption of characteristic wavelength light by atoms for quantification, requiring acid digestion pretreatment of coating samples and optimization of instrument conditions to improve accuracy. During the determination, a standard curve must be established, and quality control measures such as blank tests and spiked recoveries should be implemented. This method offers high sensitivity and good selectivity, providing reliable data support for the safety assessment of coatings.
2026-04-03
This article introduces the method of measuring ink pigment concentration using a UV-Vis spectrophotometer. The principle is based on the Lambert-Beer law, where the concentration is calculated by measuring the absorbance of the pigment solution at a specific wavelength. During operation, it is necessary to first prepare a homogeneous sample solution and establish a standard curve. Factors such as solvent selection, instrument calibration, and operational standards should be carefully controlled during measurement to minimize errors. This method is suitable for pigments with characteristic absorption in the ultraviolet or visible light regions, offering advantages such as high sensitivity and ease of operation. However, it also has limitations, such as restricted applicability to mixed pigments or insoluble particles.
2026-04-03
A spectrophotometer objectively quantifies colors by measuring the spectral data of ink. Based on the Lambert-Beer law, it converts colors into calculable spectral values, replacing traditional methods that rely on the human eye and experience. In ink color matching, this instrument is used to establish color standards, predict formulations, evaluate color differences in proofs, and control color consistency in production. It can significantly improve the accuracy and efficiency of color matching but cannot fully replace the human eye's perception of special effect colors. Proper use of this instrument is crucial for achieving precise color management.
2026-04-03
This article introduces the application of ultraviolet spectrophotometry in determining the lignin content in pulp. Lignin is a key component affecting pulp quality, and this method utilizes the characteristic absorption of lignin under ultraviolet light for measurement, offering simplicity and speed. The article explains the principle of the determination, which is based on the Lambert-Beer law, calculating lignin concentration through absorbance, and outlines the complete process from sample preparation to result calculation. Additionally, it mentions the need to consider influencing factors such as sample pretreatment and solvent selection to ensure accurate results. This method has established relevant standards for practical production monitoring and process optimization, and may be combined with other technologies in the future to enhance analytical performance.
2026-04-03
The paper absorbency tester evaluates the absorption properties of paper by measuring the penetration of liquid on the paper. In the sizing process, sizing agents alter the hydrophilicity of the paper fiber surface, thereby affecting the paper's resistance to liquids. By quantifying the absorbency index, the tester helps adjust the dosage of sizing agents and process conditions to optimize the final performance of the paper, such as printing and moisture resistance. The testing process must adhere to standard methods to ensure reliable results, which are used for production monitoring and problem diagnosis to enhance product quality and process efficiency.
2026-04-03
This article introduces the method for determining pulp chromaticity using spectrophotometry. It first explains the importance of chromaticity to pulp quality, then elaborates on the basic principle of spectrophotometry, which quantifies color by measuring the light reflection of pulp, commonly represented using the CIELAB color system. Next, the article lists the required instruments and standardized sample preparation requirements, and describes step-by-step the operational procedures for calibration, measurement, and data recording. Finally, it highlights considerations for result analysis and the application of this method in production control and relevant international standards. Overall, this is an objective and precise measurement technique that helps standardize the evaluation of pulp color.
2026-04-03
This article introduces the working principle, calibration process, operational steps, and factors affecting the measurement results of a paper whiteness tester. The instrument evaluates whiteness by measuring the reflectance of blue light from the paper. Calibration requires the use of a standard whiteboard and adherence to relevant standards. During operation, attention must be paid to environmental conditions and sample preparation, and the instrument requires maintenance after measurement. Understanding these key points helps ensure the accuracy and comparability of measurement results.
2026-04-03
This article analyzes the correlation between puncture strength and burst strength of cardboard. The two properties measure the ability of cardboard to resist dynamic impact and static pressure, respectively. Although the testing principles differ, both are closely related to the fiber structure and lamination process of the cardboard. The article explores the relationship between the two from the perspectives of testing methods, mechanisms, and data, noting that they are influenced by factors such as fiber bonding strength, humidity, and additives, and can be linked through empirical formulas to establish statistical relationships. Understanding this correlation helps optimize quality control and predict material performance.
2026-04-02
This article analyzes the impact of temperature and humidity on paper folding endurance testing. Paper folding endurance tests are typically conducted under standard temperature and humidity conditions, such as 23°C and 50% relative humidity. Variations in humidity can affect the flexibility and bonding strength of paper fibers, and both excessively low or high humidity may reduce the number of folds. Temperature changes interact with humidity, influencing the degree of plasticization of the fibers. In practical testing, it is essential to strictly control environmental conditions and ensure that samples are fully equilibrated to obtain reliable results.
2026-04-02
