Significance and Use
7.1 Not all sealants meeting this specification should be presumed to be suitable for all applications and all substrates. This specification assists in selecting sealants that meet certain minimum standards of performance.
7.2 This specification does not evaluate the adhesion of the secondary sealant to the IG unit spacer. Adhesion of the secondary sealant to the spacer is generally considered necessary for the successful performance of the IG unit edge seal.
7.3 When specifying a sealant using this specification, it is essential that the applicable type and use also be included in the requirements. This will ensure that the proper sealant is provided for the intended use.
7.4 IG units qualified by this specification shall have a low moisture vapor transmission sealant for a primary seal and a structural silicone sealant for a secondary seal.
7.5 This specification does not address appropriate sealant stiffness since the appropriate stiffness is a function of the particular insulating glass system in which the sealant is used (that is, varies with spacer, shape and set back, and sealant configuration). Test Method C1265 can assist in evaluating these aspects of the sealant in a particular IG system.
Abstract
This specification covers cold, liquid-applied, single or multi-component, chemically curing, elastomeric secondary edge sealants for sealed structurally glazed insulating glass units. Only the minimum acceptable test requirements for and the durability of these materials are described by this specification. A sealant that qualifies under this specification is classified into two types according to the number of components and into two uses according to application. Sealants should conform to the required values of extrudability, rheology, hardness, heat aging, weight loss, cracking, chalking, durability, tensile strength, and minimum shelf life.
Scope
1.1 This specification describes the properties of cold, liquid-applied, single or multi-component, chemically curing, elastomeric sealants used as the secondary seal of sealed insulating glass units, hereinafter referred to as the “sealant” (see Fig. 1). These sealants are intended to be a structural component of sealed insulating glass (IG) units used in structural sealant glazing (hereinafter referred to as SSG). Typical designs and considerations can be found in Guide C1249. Presently only certain silicone sealants are recognized as having the necessary durability for use as secondary sealant in IG units in SSG applications.
FIG. 1 Cutaway Section of IG Unit Edge Seal
1.2 This specification does not describe all of the necessary properties of the sealant. Only those properties for which there are ASTM test methods and industry-agreed-upon minimum acceptable test requirements are described by this specification. Additional properties will be added as ASTM test methods for these properties become available.
1.3 This specification only addresses the durability of the secondary edge sealants for structurally glazed insulating glass units. Durability of sealed insulating glass units can be found in specifications and guides that reside within ASTM Committee E06.
1.4 The committee with jurisdiction for this standard is not aware of any comparable standard published by other organizations.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information purposes only.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.