Initial drying resistance tester AATCC 201

In materials science, construction engineering, and industrial manufacturing, the crack resistance and surface resistance characteristics of materials during the drying process directly affect their service life and quality stability. The initial drying resistance tester, as a professional testing device, simulates the drying environment and quantifies the stress changes of materials in the early stages of drying, providing crucial data support for materials research and development, process optimization, and quality control.

The initial drying resistance tester is a specialized device used to determine the crack resistance and surface resistance of materials in the early stages of drying. Its design aims to solve the problem of traditional testing methods' inability to accurately quantify drying stress. This instrument simulates the stress state of materials during actual drying by controlling environmental parameters such as wind speed and temperature, and monitors in real time the minute deformations or cracks on the material surface caused by shrinkage or expansion. Its core modules include an axial flow fan, a test wind tunnel, a sample holder, an airflow control device, a timer, and high-precision sensors. In fields such as architectural coatings, putties, plastic films, and composite materials, this equipment has become an important tool for evaluating the weather resistance, crack resistance, and process adaptability of materials, providing a scientific basis for materials research and development and production.

Working Principle

The initial drying resistance tester operates on a dual-core mechanism of "environmental simulation + stress monitoring," achieving precise replication of the drying process through multi-physics coupling technology. Its environmental simulation system consists of an axial flow fan and a hot air heating module: the axial flow fan generates a stable airflow, and the airflow speed is precisely controlled at a set value (e.g., 3 m/s) by an airflow control device, simulating natural air drying conditions; the hot air heating module heats the air through resistance wires, and in conjunction with a temperature sensor and PID controller, stabilizes the temperature inside the wind tunnel at a target value (e.g., 25℃ to 80℃), covering the drying requirements of different materials. In the sample fixation and stress transmission stage, the test plate coated with the material to be tested is placed parallel to the test piece holder inside the wind tunnel. The airflow acts perpendicularly on the sample surface, inducing shrinkage stress. Some high-end models use built-in elastic elements or strain gauges to convert minute deformations on the sample surface into electrical signals, enabling real-time monitoring of stress changes. The data acquisition and analysis system consists of a high-precision anemometer, temperature sensor, displacement sensor, and data acquisition card. Each sensor converts physical signals into digital signals, which are then transmitted to the computer via the data acquisition card. The software algorithm filters the raw data to eliminate noise interference and ultimately generates stress-time curves, quantifying the drying resistance characteristics of the material. For example, when testing architectural coatings, a certain type of instrument can record the time of crack appearance, the number of cracks, and the maximum stress value, providing direct data support for material improvement.

Operating Procedures

To ensure the accuracy of test results, the initial operation of the drying resistance tester must strictly follow the standardized procedures. During the pre-experiment preparation stage, check that all pipe interfaces, bolts, and electrical connections are secure to avoid leaks or short circuits; clean the sample holder and the inner wall of the wind tunnel to prevent residual samples from affecting subsequent tests; start the preheating program to raise the internal temperature of the equipment to the set value (this step can be skipped for room temperature tests). During sample preparation and installation, apply the material according to standard requirements (e.g., for architectural coatings, control the coating thickness to 1.5±0.1mm), and fix the sample plate to the sample holder, ensuring it is parallel to the airflow direction and free from movement; close the wind tunnel observation window to prevent external airflow from interfering with the test environment. During the parameter setting and test start-up stage, set the wind speed (e.g., 3m/s), temperature (e.g., 25℃), and test duration (e.g., 6 hours) through the control panel; after starting the axial flow fan and data acquisition system, observe whether the anemometer and temperature sensor readings are stable; only begin testing after confirming they are correct; do not touch the sample or equipment during the test to prevent human error. In the results recording and post-processing stage, the test plate needs to be removed after the test, and the number, length, and distribution of cracks recorded; the stress-time curve from the data acquisition system exported, and the average drying resistance value calculated; the equipment cleaned and the power turned off to prepare for the next test. For example, one laboratory, through standardized operating procedures, controlled the test repeatability error within ±5%, significantly improving data reliability.

Application Areas

The initial drying resistance tester has a wide range of applications, covering multiple industries such as construction, chemical, electronics, and new energy. In the construction field, this equipment is a core tool for evaluating the drying performance of building coatings, putty, and exterior wall insulation materials. For example, by testing the drying resistance of coatings under conditions of 3 m/s wind speed and 50℃, its crack resistance performance in actual construction can be predicted, optimizing formula design;

In putty testing, the instrument can quantify its shrinkage stress, providing data support for preventing wall cracking. In the chemical industry, this equipment is used to test the drying characteristics of plastic films, rubber products, and composite materials. For example, in plastic film production, by simulating stress changes under different drying conditions, blown film process parameters can be optimized to reduce film surface defects. In rubber product testing, the instrument can assess stress release characteristics during vulcanization, improving product dimensional stability.

In the electronics field, this equipment is used for testing the drying performance of circuit board coatings, packaging materials, and optical films. For example, in circuit board coating testing, the instrument can simulate drying stress under high temperature and humidity conditions to evaluate the adhesion between the coating and the substrate. In optical film production, by testing the deformation of the film during drying, the coating process can be optimized to improve product light transmittance. In the new energy field, this equipment is used to test the drying characteristics of lithium battery separators, photovoltaic backsheets, and hydrogen fuel cell membrane electrodes. For example, in lithium battery separator testing, the instrument can quantify shrinkage stress during drying to prevent separator deformation from causing battery short circuits. In photovoltaic backsheet production, by simulating outdoor drying conditions, the weather resistance of the backsheet material can be evaluated, extending the lifespan of photovoltaic modules.

Maintenance and Repair

Maintenance and upkeep of the initial drying resistance tester are crucial for ensuring its long-term stable operation.

For routine maintenance, the equipment casing and wind tunnel interior should be cleaned regularly to prevent dust accumulation from affecting heat dissipation; check for loose axial fan blades to avoid unstable airflow due to vibration; and clean residual samples from the sample holder to prevent corrosive substances from damaging metal components.

For periodic maintenance, sensor accuracy should be checked quarterly, displacement sensors calibrated using standard weights, and anemometer parameters adjusted using a wind speed calibrator; the air filter should be replaced every six months to prevent dust from entering the wind tunnel.

Annually, a comprehensive inspection of the electrical system should be conducted by professionals, replacing aging wiring and contactors. For troubleshooting, if there is no airflow output after startup, check the axial fan power supply or replace the damaged fan motor.

If temperature control is unstable, check for a broken circuit in the hot air heating module's resistance wire or adjust the PID controller parameters; if the data acquisition system has no signal, check for loose sensor connections or replace the data acquisition card.

The initial drying resistance tester, with its precise environmental simulation capabilities, adaptability to multiple scenarios, and scientific data analysis system, has become an indispensable "technical tool" in the field of materials research and development and quality control. From optimizing the crack resistance of architectural coatings to improving the stability of new energy materials, from meticulous daily maintenance to rapid troubleshooting, its full life-cycle management not only ensures the reliability of test results but also promotes the development of materials science towards higher performance and greater sustainability. In the future, with technological iteration and upgrades, this equipment will demonstrate its value in more emerging fields, injecting lasting momentum into materials innovation and industrial upgrading.