Definition
Coating test jam paper is a standardized substrate specifically designed for the performance evaluation of coatings, inks, and related coating materials. It is usually made of cardboard with a specific weight, thickness, surface flatness, and oil absorption, and is calendered to ensure consistent physical and chemical properties. As a coating carrier, the cardboard provides a reproducible reference base for simulating actual coating effects and quantifying coating properties in a laboratory environment.
Principle
The working principle of coating test jam paper is based on its properties as a uniform, inert substrate under controlled conditions. When the paint or ink to be tested is coated on the surface of the cardboard in the prescribed method and cured, the whiteness, gloss, smoothness and absorbency of the jammed paper itself will not have significant interference with the subsequent measurement, so that the test results mainly reflect the performance of the coating material. The core of this method is to eliminate errors caused by substrate variation by standardizing the substrate, ensuring that the test data between different batches and laboratories is comparable.
Measurement method
Testing with coating test jams typically follows a standardized set of operating procedures. First, prepare the jammed paper sample according to relevant standards (such as GB/T, ISO, ASTM, etc.) to ensure that it is in the specified temperature and humidity environment. The specimen is then evenly applied to the surface of the paper using a wire stick applicator, scraper or spraying equipment. After coating, dry or cure under standard conditions. Finally, various properties are measured on the coating, and common items include: coating thickness, gloss, color difference, adhesion, hardness, friction resistance, etc. Each test needs to record environmental conditions, coating parameters and measuring instrument information.
Influencing factors
The accuracy and repeatability of test results are influenced by a variety of factors. The performance of the jam paper itself is key, and the difference in surface smoothness may lead to uneven coating thickness distribution. Whiteness and color may affect the judgment of color and coverage; Different levels of oil absorption can change the leveling and curing process of the coating. Environmental conditions, especially temperature and relative humidity, can affect the rheological properties and drying speed of the coating. In coating operation, the choice of applicator, coating speed and pressure are also important variables. In addition, the drying or curing time and conditions of the coating must be strictly controlled to avoid measurement deviations.
Application
Coating film test cardboard is widely used in R&D and quality control processes in coatings, inks, adhesives and other industries. In the R&D stage, it is used to screen resins, pigments, additives, and optimize product formulations. In quality control, it is used to inspect the batch consistency of raw materials and finished products. Its test results support product conformity statements and serve product performance evaluation in various fields such as architectural decoration, furniture manufacturing, printing and packaging, and automotive painting. Standardized testing also provides a common technical language for technical exchange and trade within the industry.
Selection
Choosing the right coating film test jam paper requires comprehensive consideration of the purpose of the test and relevant standard requirements. First of all, the specific national or international standards to be followed should be clarified, which usually stipulate or recommend the technical parameters of cardboard, such as quantification, thickness, whiteness, gloss, etc. Secondly, the type of paper jam is selected according to the characteristics of the material being tested, for example, a high-gloss coating test may require a paper jam with an extremely smooth surface, while some tests may require a specific level of oil absorption. Users should also pay attention to the batch stability of the jammed paper, and the quality consistency certificate provided by the supplier is an important reference. In actual selection, it is feasible to conduct preliminary comparative tests to verify the compatibility of the jam with the test system.