Degradation in adhesive bonds due to moisture is probably the major cause of in-service failure in adhesively bonded structures. The ubiquitous nature of water combined with the ability to penetrate into the adhesive structure poses considerable problems. If adhesive products are exposed to moisture at rising temperature for a long or short time period, it can easily produce irreversible chemical and physical changes within itself. The natural process of moisture absorption in adhesive structures is normally very slow, and this makes it very difficult to reach an adequate degree of degradation in a structural test element in practical timescales. Hence, there is a need for employing an accelerated moisture diffusion method using a humidity chamber to produce a similar degradation condition investing less time.
How can moisture damage the properties of an adhesive?
Moisture influences the adhesive by plasticization and swelling, which may decrease joint strength. In addition, water can disrupt interfacial bonds in a causing non-reversible damage, as predicted by the theories of adhesion, or cause failure by corrosion of the underlying metal substrate. The usual approach used to accelerate moisture uptake is to increase the diffusivity of the adhesive by elevating the temperature of the conditioning environment. Further rate of acceleration can be achieved by raising the relative humidity level.
To evaluate the amount of damage occurred due to moisture content is tested in industries using a proficient Humidity Test Chamber. It is a unique test cabinet designed to create temperature and relative humidity inside the chamber to detect the change in the physical characteristics of the material and to ascertain the actual working life of the testing device. It complies with the testing standards of ASTM D1776, ASTM D1776M-15, BS950 Part-1(D65).
Few key features offered in the machine are:
- It is designed to simulate the environmental factors using sophisticated technology controlled by the users from the front panel.
- It is manufactured using glass wool insulation to reduce heat loss and produce better testing conditions.
- It allows the operators to set multiple parameters easily.
- The device can be operated utilizing hassle free controls.
- Profile programs can be configured to 8 programs to run the machine automatically so that it can work at 8 different time intervals in one go.
- The temperature for all the 8-time intervals can be set individually.
For more information about the testing instruments we deliver or to get any technical guidance, kindly contact our team here.
