When an enterprise user uses the weather-resistant adhesive produced by our company, the glue seam appears more serious foaming phenomenon. After the research of our company's technical experts, the following causes of foaming are obtained:
First, the influence of various operations during construction may cause foaming
1. The glue seam and the substrate humidity is large, there is rain;
2. Accidentally cut the foam rod during construction;
3. If the foam rod is not selected correctly, low-density foam cannot be used, and the closed-mouth foam rod must meet the relevant specifications;
4. The thickness of sizing is not enough or too thin;
The above factors can be avoided, in the construction must ensure that the glue joint and substrate is dry and clean, pay attention to the operation can not be scratched foam rod, according to the size of the joint to choose the appropriate foam rod.
Two, the temperature difference is too big cause glue seam foaming. First of all, in summer, the temperature is very high during the day and the humidity is very high. If the construction is especially easy to bubble in the morning or afternoon, because the silicone weatherproof adhesive is solidified by absorbing the moisture in the air at a certain temperature. When in the morning or afternoon after sizing, the silica gel curing speed is very fast, the silicone gel curing process will release chemical substances to form gas, aggregated together can not immediately escape from the gel. This will cause blistering phenomenon, generally this situation occurs in the facade of the sun and curtain wall assembly size long side of the glue seam, in the evening when the sun goes down sizing, can alleviate this phenomenon.
The phenomenon may be caused by the large temperature difference between day and night, the low temperature and the dry climate in winter. It takes a long time for colloid to cure in winter. When colloid is fully cured after construction, each unit of the curtain wall itself has a certain displacement. In addition, the temperature difference between day and night is too large to produce a greater displacement.
The above phenomenon only affects the appearance of some curtain wall joints, but does not produce any adverse results on the performance indicators of the colloid. The phenomenon will be alleviated with the decrease of the temperature difference.
Because the silicone weatherproof adhesive has excellent weather resistance and strong resistance to high and low temperature, it is recommended that it can be constructed under the following conditions:
1. Please avoid the construction in rainy weather and pay attention to the weather conditions during this period of sizing. It is better to have no rainy day.
2. When sizing, it is necessary to let the glue seam and the glue in contact with the substrate is dry.
3. Work between 11am and 3pm in winter and in the morning or evening in summer.
4 do a test before construction, to observe the solidification of the glue extrusion, determine the table dry time, in the table dry time dressing surface. 【 the 】