Gas retention capacity of secondary sealant in IGU production

Gas retention capacity of secondary sealant in IGU production

-by DETEK machine

A wide variety of sealants are used to seal insulating glass units and the most important performance features of a sealant are the following:

(a) Compatibility with glass, spacer, desiccant and glazing materials.

(b) Low water vapour transmittance.

(c) Good adhesion.

(d) Resistance to service conditions, such as UV and structural movement.

Or in short:

Sealant Functions

1.    Gas & Moisture Barrier

2.    Chemical Fog Resistance

3.    Long Term Durability

4.    Thermal Performance

5.    Structural Capacity of Unit

Sealant Types

Hot Melt Butyl

Polysulfide

Polyurethane

Polyisobutylene

Silicone

Extrudable Polyurethane

The most common sealant types used for insulating glass units are butyl, polysulphide, polyurethane and silicone. Some manufacturers use two of these sealants in combination to create a dual seal. In such cases, compatibility should be checked. There is a wide range of formulations available in each sealant type and manufacturers should be consulted about the properties of their formulation. It should be noted that some of these sealants are incompatible; i.e. they cannot be used together.

The most common used inert gas is Argon, European standards aim to gas fill level of 90% with permitted annual leakage less than 1% setting high requirements for the process. However, the secondary sealant is not water and gas tight, so we must make the primary sealant seal tight.

The purpose of this article was to provide the new glass processor companies with basic understanding of gas inside insulating glass, and how to detect the gas concentration and keep it within insulating glass unit.