Based on the research of our company's technical experts, we have identified the following causes of blistering in the adhesive seam of a certain enterprise user who experienced severe blistering when using our company's weather resistant adhesive:
1、 The impact of various operations during construction may cause blistering
1. The humidity of the adhesive joint and substrate is high, and there is rainwater;
2. Cut the foam rod carelessly during construction;
3. The selection of foam rod is wrong, and the foam rod with low density must be closed type foam rod conforming to relevant specifications;
4. The thickness of the adhesive application is not enough or too thin;
The above factors can be avoided. During construction, ensure that the adhesive joint and the base material are dry and clean. Pay attention not to scratch the foam rod during operation. Select the appropriate foam rod according to the size of the joint.
2、 Excessive temperature difference can cause blistering in the adhesive seam. Firstly, let's talk about the situation in summer. During the day, the temperature is very high and the humidity is high. If you work in the morning or afternoon, it is particularly easy to foam because silicone weather resistant adhesive solidifies by absorbing water from the air under certain temperature conditions. When applied in the morning or afternoon, the curing speed of silicone gel is very fast. During the curing process of silicone gel, chemical substances will be released to form gas, which cannot immediately escape from the gel when gathered together. This can cause blistering, which usually occurs between the sunny side of the curtain wall and the long side of the curtain wall component. Applying glue in the evening when the sun sets can alleviate this phenomenon.
Due to the large temperature difference between day and night in winter, the temperature is low, and the climate is relatively dry, which may cause this phenomenon. In winter, the solidification of colloids takes a long time. After the construction of colloids, when they are not fully cured, each unit component of the curtain wall itself has a certain displacement. In addition, the large temperature difference between day and night produces a greater displacement. When the colloids are not fully vulcanized, their resistance to displacement is poor, which leads to the phenomenon of weather resistant adhesive joint bulging.
The above phenomenon only affects the aesthetics of some curtain wall adhesive joints, but does not have any adverse effects on the performance indicators of the gel. This phenomenon will be alleviated as the temperature difference decreases.
Due to the excellent weather resistance and strong high and low temperature resistance of silicone weather resistant adhesive, it is recommended to construct under the following conditions:
1. Please avoid construction on rainy days and pay attention to the weather conditions during the adhesive application period, as there will be no rainy days
2. When applying adhesive, it is necessary to ensure that the adhesive seam and the substrate in contact with the adhesive are dry
3. Construction is carried out during the period from 11am to 3pm in winter, and in the morning or evening in summer
4. Conduct a test before construction, squeeze out the adhesive to observe the curing condition, determine the surface drying time, and trim the surface within the surface drying time. End