GUANGZHOU BAIYUN TECHNOLOGY CO., LTD. zhengjinghui@china-baiyun.com 86-20-3731-2985
As an important auxiliary material widely used in bonding and sealing in the fields of building curtain walls, doors and windows, interior decoration, etc., sealant plays a role in every subtlety, even in winter, it has never stopped working diligently to isolate the cold from the "barrier".
Today, let's take a look at how to correctly apply silicone structural sealants in winter.
The ambient temperature is very low in winter, and the following problems may occur:
(1) Under low temperature and low humidity conditions, the curing speed and bonding speed of silicone structural sealant are slower than normal, which will lead to longer curing time and affect construction.
(2) When the temperature is too low, the wettability of the silicone structural sealant and the surface of the substrate is reduced, and there may be imperceptible fog or frost on the surface of the substrate, which affects the adhesion between the silicone structural sealant and the substrate.
PART 01
Countermeasures for slowing down curing
(1) Take appropriate heating measures;
(2) The two-component sealant is first subjected to a pull-off test to determine the appropriate mixing ratio;
(3) One-component sealants need to be tested for surface drying time to determine whether they can be cured in this environment;
(4) It is recommended to extend the curing period after sizing to ensure that the sealant has sufficient curing and curing time.
PART 02
Countermeasures against bond failures
(1) The adhesion test should be done in advance before construction, and the construction should be carried out in strict accordance with the recommended method of the adhesion test.
(2) If necessary, consider using xylene to clean and apply primer solution to promote the speed of bonding and reduce the risk of poor adhesion due to low temperatures.
(3) After the completion of the silicone structure sealant injection, the curing process should be in a clean and ventilated environment, and when the temperature and humidity of the curing environment are low, the curing time should be appropriately extended. Among them, the curing of one-component structural adhesive sealant has an obvious relationship with the curing time. In the same environment, the longer the curing time, the higher the degree of curing.
If necessary, measures can be taken to increase the ambient temperature and humidity. In the end, the sealant tapping test should prevail, and the curing time of the finished single parts should be fully determined. After the finished sealant tapping test is qualified , it can be installed and handled.