China's spring climate is characterized by dryness, low humidity, large temperature difference in the north, and heavy rain and humidity in the south. Climate environmental impact on site construction conditions, sealant solidification will have an impact, but also may have an impact on construction efficiency and quality. Baiyun Chemical Co., Ltd. shares with you the matters needing attention in spring construction of door and window sealant based on years of experience in application of door and window sealant.

Door and window sealant is mainly used for sealant sealing of frame and glass of doors or windows, and sealant sealing of frame and wall, which plays a sealing and waterproof role, as shown in Fig. 1. Almost all door and window sealants on the market are single-component silicone sealants, which need to react with water vapor in the air to cure. The curing process is affected by environmental temperature and humidity. The lower the environmental temperature and humidity, the slower the curing speed of sealant will be.
Before the construction of door and window sealant, the compatibility and adhesiveness test of sealant with base material and related accessories should be qualified. Sealant should be stored in the storage period stipulated by the manufacturer. At the same time, the dry, anti-sticking and cured quality performance of the sealant can meet the requirements of door and window assembly.

During the construction process, the construction should be carried out in accordance with the construction environment recommended by the sealant manufacturer. For example, the recommended construction environment of Baiyun silicone sealant is: temperature 4 ~40 C, relative humidity 40%~80%. Different manufacturers may have different requirements for construction environment, which should be confirmed before construction.

In spring, it is rainy and humid in the south, which easily causes the surface of the base material at the seam to be wet. If the base material surface is not dry enough before construction, there is water vapor, which may cause sealant foaming, see Figure 2 left; wet seam will also affect the sealant bonding performance, thus affecting the construction quality, as shown in Figure 2 right. In wet weather construction, it should be fully confirmed that the dry surface of the base material can be constructed. In addition, too high humidity will have a slight impact on the dry time of the sealant meter and the time of surface debonding.

It is suggested that the curing speed of sealant may be slowed down due to the dry weather and low humidity in the north of China in spring. It is suggested that the curing time after the construction of sealant can be prolonged appropriately, and that the large stress on sealant joints caused by the construction of sealant should be avoided, resulting in the deformation of sealant joints. See Figure 3. For the assembly construction of doors and windows in doors and windows factories, gluing construction is needed on both sides of the windows and doors inlaid glass. Usually, gluing construction is carried out on one side first, and gluing construction is carried out on the other side after solidification of the sealant. For the construction of turning over, it is necessary to ensure that the sealant solidified to a certain extent to resist the deformation of the seam caused by turning over. It is suggested that heating or humidifying measures should be adopted in the construction process to improve the indoor temperature and humidity conditions and accelerate the curing speed of sealant.

In a word, due to the great difference of climate between the north and the south in spring construction, there will be different concerns in the construction process between the South and the north. Spring weather changes greatly, resulting in corresponding changes in the construction environment conditions, we should do a good job in the quality control of door and window sealant construction. If the environmental conditions exceed the requirements of construction technology, it is suggested that small area gluing test should be carried out first, and the bonding test should be carried out to confirm that the bonding is good and the appearance is no problem, then large area use should be carried out to ensure the construction quality of the door and window sealant.