How To Choose The Right Door And Window Sealant?

Sealant is one of the essential materials for the installation of doors and Windows, mainly used for the connection between the door and window frame and the external wall, the inner and outer sealing of the glass installation or the connection between the door and window frame and the outer side of the frame, which plays the role of sealing, waterproof, closing and beautiful.

Although the sealant accounts for the cost of door and window installation is very small, but once the door and window sealant fails, aging, cracking, falling off and other problems will seriously affect the air tightness and water tightness of doors and Windows, and even lead to doors and Windows and walls, water seepage, water leakage and other major problems.

Why does sealant fail?

1. Sealant quality reasons:

a. Improper selection of materials, the selection of sealant products rich in mineral oil. Over a long period of time, with the continuous precipitation of mineral oil, the joint colloid causes excessive shrinkage, rigidity, loss of displacement ability, and can not adapt to the displacement amount of thermal expansion and cold contraction of the substrate resulting in cracking.

b. The content of crosslinking agent in the formula is small, which is not enough to generate a perfect crosslinking network structure of the sealant reaction, and there are structural defects, which are easy to lead to colloidal cracking.

c. The sealant is not used within the validity period.

2. Application reasons

A. The formation of a large number of bubbles in the sizing process is easy to lead to colloidal cracking.

b. Uneven sizing thickness is easy to cause colloids to crack in thin places.

c. When the surface temperature of the substrate is too high or too low, the gel is easy to crack after the sealant is cured.

d. The sealant is subjected to external force during the curing process, which can easily lead to cracking of the gel after curing.

e. Subject to large external forces or large deformation of the substrate, such as earthquakes, typhoons, etc., colloids may crack.

3. The sealant does not match the application scenario

a. The displacement capacity of the selected sealant can not meet the displacement requirements.

b. The modulus of the selected sealant does not meet the joint requirements.

c. The sealant is poorly bonded to the substrate, resulting in poor sealing effect. Usually manifested as the stripping of the substrate and sealant.

How to choose the right door and window sealant?

1. Pay attention to the displacement ability of sealant

In the selection process of sealant, in addition to the standards it meets, it should also pay attention to its corresponding displacement level. Displacement capacity is the most key indicator to measure the elasticity of sealant, the higher the displacement capacity, the better the elasticity of sealant. The processing and installation of doors and Windows should choose products with displacement capacity of not less than 12.5 to ensure the long-term air tightness and watertightness of doors and Windows.

High displacement level products have a stronger ability to withstand changes in joint displacement, and it is recommended to choose products with high displacement level as much as possible.

2. According to the use of the correct choice of sealant products

Hidden frame window and hidden frame opening fan need structural sealant to play a structural bonding role, and silicone structural sealant must be used, and its bonding width and thickness must meet the design requirements.

In the process of door and window installation, the sealant used for stone joints or joints with stone on one side should be selected in line with GB/T 23261 standard stone special sealant.

Fireproof doors and Windows or building exterior doors and Windows that have requirements for fire integrity are more suitable for fireproof sealant.

For applications with special requirements for mildew prevention, such as kitchens, bathrooms and dark and damp parts, the joint sealing of doors and Windows should be made of mildew resistant sealant.