Degradation of adhesive properties due to moisture can be the main cause of failure of bonded structures in service. The ubiquitous nature of water and its ability to penetrate into adhesive structures poses considerable problems. If the adhesive product is exposed to a humid environment for a long time or a short time under elevated temperature conditions, it is easy to produce irreversible chemical and physical changes inside. The natural process of moisture uptake in adhesive structures is often very slow, making it difficult to achieve sufficient levels of degradation in structural test elements on practical timescales. Therefore, accelerated moisture diffusion methods using Humidity Chambers are needed to generate similar degradation conditions with less time investment.
How does moisture damage the performance of adhesives?
Moisture affects the adhesive through plasticization and swelling, which can reduce joint strength. In addition, water can disrupt interfacial bonds, causing irreversible damage, or failure by corroding the underlying metal substrate, as predicted by adhesion theory. A common method used to accelerate moisture absorption is to increase the spreadability of the adhesive by increasing the temperature of the conditioning environment. Further acceleration can be achieved by increasing the relative humidity level.
To assess the extent of damage that has occurred due to moisture content, tests are performed in the industry using skilled humidity testing chambers. It is a unique test cabinet designed to create temperature and relative humidity in a room to detect changes in the physical properties of materials and determine the actual working life of test equipment. It meets the testing standards of ASTM D1776, ASTM D1776M-15, BS950 Part-1(D65).
A few key functions provided in the machine are:
It is designed to simulate environmental factors using sophisticated techniques controlled by the user from the front panel.
It is manufactured using glass wool insulation to reduce heat loss and produce better testing conditions.
It allows the operator to easily set multiple parameters.
The device can be operated using worry-free controls.
The profile program can be configured into 8 programs to automate the machine so that it can work at 8 different time intervals at a time.
The temperature for all 8 time intervals can be set individually.
