Are weatherproof sealants the same as structural sealants?

Silicone sealant is divided into two categories: structural sealant (structural adhesive) and weather resistant sealant (such as: door and window glue, external wall glue, anti-mold glue, fireproof glue, etc.).

They have many performance requirements are similar, but like weatherproof glue more emphasis on atmospheric change resistance, ultraviolet resistance, aging resistance and other performance; The structural sealant (structural adhesive) is more important requirements for strength, extensibility, bonding properties and other mechanical properties.

Although the two are the same sealant, but because the application of the two scenarios and focus are not the same, they should be selected according to the role and purpose of use of the sealant.

1.Weather Resistant Silicone Sealant

Weather-resistant sealant is a single component, neutral curing silicone sealant, specially manufactured for various curtain wall weather-resistant sealing silicone sealant, with excellent weather-aging resistance.

Silicone weather-resistant sealant is formed by reacting with water in the air to form elastic silicone rubber at room temperature, which is mainly used for sealing the joint between the curtain wall plates.

Because the plate is often affected by temperature change, the main structure deformation and displacement, resulting in joint width will also change. This requires that the weather resistant adhesive has a good ability to withstand joint displacement.

2.Structural Silicone Sealant

The structural sealant (structural adhesive) used in aluminum alloy glass curtain wall is mainly silicone structural adhesive, because structural adhesive is usually used to connect glass and glass, glass and aluminum, withstand wind, seismic action, weight and temperature changes, etc., plays an important structural role in the curtain wall, so the mechanical properties of its higher requirements.

3.How to choose silicone sealant?

The selection of suitable weather resistant sealant and structural sealant should pay attention to the following problems.

(1) The two shall not be used for each other. In particular, structural adhesives should not be used as weather-resistant adhesives. Although the price of structural adhesive is expensive, other properties are also very good, but the weather resistant adhesive is mainly used for external building sealing, and there are higher requirements for weather resistance, which is difficult for structural adhesive.

(2) Both must use neutral glue, should be used within the validity period, expired weather resistant glue and structural glue should not be used.

(3) The glue used must hold the national certificate and various performance test reports, when used in curtain wall engineering, the manufacturer should also be required to provide the corresponding test report.

(4) For structural adhesive, in addition to doing a variety of performance tests, should also do the compatibility test with the contact material, the so-called compatibility refers to the structural adhesive in contact with these materials, only the bonding effect, does not affect any chemical changes in the bonding performance.