Definition
A solvent wipe resistance tester is a type of laboratory equipment used to evaluate the resistance of surface materials such as coatings, coatings, or printed layers under the action of specific solvents. The instrument quantitatively detects the ability of the surface layer to resist solvent erosion or dissolution by simulating the scenario where the material may come into contact with solvents in actual use, and provides key data for material durability evaluation.
How it works:
The core working principle of the instrument is based on the combination of mechanical reciprocating friction and solvent action. The device typically consists of a platform to hold the sample, a wipe head that can apply constant pressure, and a drive system. The wipe tip wraps a standard wipe material (e.g., cotton cloth) and impregnates with a prescribed solvent to reciprocate the sample surface at a set speed, stroke, and pressure. During the test, the solvent resistance of the coating is quantified by recording the state when it first appears exposed or when it reaches a predetermined number of wipes. Its basic action relationship can be expressed as:
Wiping force = applied pressure × contact area
The instrument ensures consistency and repeatability of the testing process by precisely controlling these parameters.
Measurement method
Measurements are usually made in accordance with relevant national or international standards (e.g. test methods for coatings to resistant to liquid media in ASTM, ISO, GB/T, etc.). The main steps include: preparing a flat specimen that meets the dimensional requirements and adjusting its condition; Select a standard solvent that matches the purpose of the test (e.g., ethanol, acetone, ethyl acetate, etc.); Install the wiping material soaked in solvent on the wiping head and apply the specified pressure; Set the wiping speed and the length of a single stroke; Start the instrument to wipe. There are generally two termination conditions: one is to observe that the coating is rubbed through to the substrate, and record the number of wipes at this moment; The second is to check the degree of change in gloss, color, wrinkling and other changes on the surface of the coating after reaching the predetermined number of times. Results are reported in terms of passes or failures.
Influencing factors
Test results are influenced by multiple factors. In terms of instrument parameters, the wiping pressure, speed, frequency and the geometry of the wiping head directly affect the shear force and solvent amount acting on the coating. Solvent properties are key variables, including the chemical composition of the solvent, polarity, volatility, and dissolution parameters to the coating material being tested. Environmental conditions such as temperature and humidity can affect the volatilization rate of solvents and the physical state of the coating. The sample's own factors, including coating thickness, curing degree, adhesion, and substrate properties, all had a significant impact on the results. Operational consistency, such as the frequency of wiping material replacement and solvent replenishment intervals, also need to be strictly regulated.
Applications:
This instrument is widely used in industries that require durability verification of surface treatment layers. In automotive manufacturing, it is used to test the resistance of interior coatings, exterior paints, etc. to cleaning agents or fuels. In the electronics industry, it is commonly used to evaluate the resistance of enclosure spraying, printed circuit board solder masks, or display coatings to cleaning solvents. Furniture and building materials industry for testing the stability of wood paints, metal coatings or plastic finishes to common chemicals. In addition, it is also a common tool for quality control and R&D comparison in the fields of ink printing, packaging materials and industrial protective coatings.
Selection considerations
Choosing the right solvent resistance wipe tester requires comprehensive consideration of testing needs and technical specifications. First of all, it is necessary to clarify the standard system to be followed to ensure that the stroke, pressure range, speed control and counting functions of the instrument comply with the standard regulations. The accuracy and stability of core mechanical properties such as pressure control and operation smoothness directly affect data reliability. The instrument should have good solvent compatibility, i.e., key components that are resistant to corrosion from the test solvent. User-friendly design, such as easy sample gripping, easy wiping tip replacement and solvent addition, can improve efficiency. The completeness of data logging capabilities, such as automatic counting and shutdown, helps reduce human error. In addition, the supplier's technical support and after-sales service, as well as the durability and maintenance convenience of the instrument itself, are also factors that guarantee long-term use.