The recommended application temperature for the door and window sealant is between 4 and 40 degrees Celsius, and it should be used in a clean environment with a relative humidity of 40% to 80%. This will result in better bonding performance. If the temperature is too low, it may cause a slower curing speed, a slower bonding speed, and even a situation where it does not bond with the substrate. If the temperature is too high, it may cause the surface temperature of the substrate to be too high, and the curing reaction speed of the sealant may be too fast, with small molecular gas by-products unable to be promptly expelled, thus causing bubbles. If the temperature is below 4 degrees Celsius, it is necessary to strengthen the quality control of the construction process to ensure that there are no problems with curing and bonding before proceeding with the construction.

1. Choose a type of adhesive with a relatively fast curing speed. Do not use the weather-resistant sealant that contains mineral oil, because the oil-filled adhesive will shrink significantly during the curing process. This may alleviate the bulging phenomenon to some extent, but such products do not meet the international standards for weather-resistant sealants. 2. When constructing under the condition of a small deformation of the joint and a temperature difference between the panels, if it is cloudy the next day, complete the construction as soon as possible on the same day. Because there is no sunlight exposure, the temperature difference between the panels is small, and the deformation of the adhesive joint is small, making it less likely to cause the bulging phenomenon. 3. At the narrowest point of the adhesive joint (when the panel inside is exposed to sunlight for construction and the glue is applied), the bulging phenomenon can be improved.

Judgment of the bulging phenomenon: Firstly, the joint of the curtain wall panel exposed to sunlight shows a large area of unevenness, while the joints not exposed to sunlight are all smooth; Secondly, by cutting the joint, it can be seen that the uneven joint with fully solidified glue is solid. Judgment of the bubbling phenomenon: Firstly, the surface of the sealant is mostly continuous or single bubble-like protrusions; Secondly, when cutting the corresponding position of the sealant, it is hollow, and this may exist on the sunny or shady side of the curtain wall.

The manifestation of this problem is that the appearance of the sealant is uneven, and after cutting, its interior is solid, which is known as bulging phenomenon in the industry. The reason for the bulging phenomenon is that the weather resistant adhesive of the curtain wall joints has not cured to a sufficient depth within 24 hours, which cannot resist the significant deformation of the joints and ultimately leads to uneven surface of the adhesive joints.

This is mainly a manifestation of mold growth in the sealant. Why does the sealant get moldy? We live in this world, and it is actually filled with a large number of microorganisms. For example, the spores of mold will grow rapidly under conditions of moisture, warmth, and nutrients. In our kitchens and bathrooms, the surface of the sealant often has some residual water marks and some residual nutrients, so it is more likely for these molds to grow on it. If mold grows on the surface of the sealant, it will not only make the surface of the sealant unattractive, but also have a certain impact on our health.

The elasticity of weather-resistant glue is stronger than that of structural glue, but structural glue performs better in terms of adhesion and load-bearing capacity. Both have properties such as resisting acid rain, UV radiation, and aging. In terms of application, structural glue is mainly used for the structural assembly and non-structural assembly of curtain walls. While weather-resistant glue is used for sealing and waterproofing at joint positions between various materials. In summary, the hardness, strength, and price of structural glue are all higher than those of the same grade of weather-resistant glue. However, the choice should be made based on the specific application.