Definition
The Ink Wash Resistance Brush Meter is a specialized inspection equipment used to evaluate the ability of ink coatings on the surface of printed materials to resist peeling or abrasion under simulated washing or friction conditions. The instrument quantifies the binding fastness between the ink layer and the substrate material through standardized mechanical action and load conditions, providing key data support for the durability of printed materials. Its test results are widely used in quality control in industries such as printing, packaging, textiles and consumer goods manufacturing.
Principle
The core working principle of the instrument is based on simulating friction and washing in actual use. During testing, the specimen is fixed on a horizontal platform so that the standard bristles or friction head reciprocateically rub the ink surface along a fixed trajectory at a specific pressure. Standard washing solution can be added simultaneously during the friction process to simulate wet rubbing conditions. The instrument is usually equipped with a counter to record the number of frictions, and the critical number of times when the ink layer is obviously exposed or damaged is determined by vision or instrument assistance, which is the value to characterize the washing resistance of the ink.
Measurement method
The measurement process follows a standardized process. First, the specimen is prepared according to relevant standards (such as GB/T, ISO, ASTM, etc.) and fixed flat on the instrument test bench. The type of brush head, applied load and friction speed are selected according to the standard requirements. The test can be set to dry or wet friction mode, and wet friction requires the use of a specified concentration of washing solution. After starting the instrument, the brush head moves back and forth according to the set stroke, and the operator regularly observes the state of the ink layer, stops the test when the ink layer wears out in the specified area or the substrate material is exposed, and records the number of frictions as the measurement result. Some advanced models are equipped with optical sensors that automatically determine the end point.
Influencing factors
The measurement results are influenced by multiple factors. The characteristics of the ink itself, such as the adhesion of the resin binder, the dispersion of the pigment and the degree of curing, constitute the basic influencing factors. The surface energy, roughness and absorbency of the substrate directly affect the adhesion strength of the ink. In the test parameters, the hardness of the bristles, the applied pressure, the frequency of friction, and the composition and temperature of the washing solution will all change the physical and chemical conditions of the friction interface. Ambient temperature and humidity may also play a role in the results by affecting the state of the material. Therefore, standard testing requires strict control of the above variables to ensure comparability of results.
Applications
This instrument is mainly used in areas where print durability needs to be verified. In the packaging industry, it is used to test the wear resistance of printed marks on food and daily chemical product packaging when handling, storing or coming into contact with humid environments. Textile printing is used to evaluate the retention of printed patterns on fabrics after repeated washing. In stationery and consumer goods manufacturing, it is used to test the abrasion resistance of product shells or label printing. In addition, this equipment is also commonly used in ink formulation research and development, printing process optimization, and raw material inspection to provide a basis for product durability design.
Equipment selection considerations
The selection should comprehensively consider the testing requirements and technical parameters. First of all, the standard system to be followed should be clarified to ensure that the instrument structure, brush head specifications and motion parameters meet the standard provisions. The test load range and adjustment accuracy need to cover the requirements of the sample to be tested. The stability of equipment operation and counting accuracy are the basis for ensuring data reliability. For diverse test scenarios, models with wet and dry friction mode switching, compatibility with multiple brush heads, and adjustable test speed can be considered. The degree of automation, such as automatic dosing, automatic endpoint determination, and data logging functions, can improve testing efficiency and consistency. In addition, equipment maintenance convenience, safety protection design, and supplier technical support capabilities should also be included in the evaluation.