Sealant glossary

Each profession or industry has its own jargon or technical terminology, be it medical doctors, geologists, craftsmen in the building trade, joiners, painters or glaziers. This permits convenient communication within the respective communities. We would like to explain some technical terms to you relying on the following extract from the Glossary of IVD (“Industrieverband Dichtstoffe” – Association of the Sealants Industry). The complete glossary (“Dichtstofflexikon”) in German with translation of the keywords into English and French is available from us or from IVD directly.

Adhesion failure

Sealant detaching from the adherent surface of the substrate (DIN EN 26927:1990), loss of adhesion.

Back-filling material, back-up material

Material introduced into a joint to limit the thickness of the sealant, thus determining the rear section of the sealant. (DIN EN 26927:1990)

Cohesion failure

Failure within the sealant (DIN EN 26927:1990)

Cross-linking

In macromolecular chemistry (the chemistry of large molecules or polymer chemistry) cross-linking means the three-dimensional linking of polymer chains to form polymer networks. This cross-linking is the cause of solidification of chemically reacting sealants, e.g. silicone sealants

Elastic recovery

The ability of a deformed sealant to regain its original dimensions totally or in part after the forces causing deformation have ceased to act upon it. (DIN EN 26927:1990)

Elongation at break

Maximum elongation of a sealant in a joint leading to failure (destruction) of cohesion in the sealing material or to adhesion failure. The elongation at break must not be confused with the maximum movement tolerance.

External quality control

Sealants tested to specific quality standards, e.g.. DIN 18545 are routinely tested for compliance with quality requirements by independent testing institutions.

Haftgrund/ Haftgrundierung

view Primer

Joint

Intended space or space due to tolerance between building components/parts (DIN 52460:2000)

Joint edge

Lateral limit of the joint width (DIN 52450:2000)

Maximum allowed distortion

Deformation range (including elongation, compression and shearing) within which the joint seal remains intact and functioning. (DIN 52460:2000)

Maximum movement tolerance

maximum allowed distortion under which the joint seal retains its sealing properties.

MS-Polymer

A raw material used for manufacturing sealants

Open time

Minimum waiting time between applying a primer and introducing the sealant. (DIN EN 26927:1990)

Polymer

substance composed of molecules made up of repetitive series of identical or different atoms or groups of atoms.

Primer

Material for surface coating of joint edges applied before introducing the sealant in order to ensure adhesion of the latter. (DIN EN 26927:1990) –> Open time (of primer)

Sealing

Introduction of suitable materials into a joint in order to prevent penetration of moisture and/or air between building components and other parts or components made of identical or different materials. (DIN EN 26927:1990)

Shore-A-Hardness

A measuring method for the rubber industry used for vulcanised rubber mixtures. It is only of limited value for testing sealants since the time of “vulcanisation” cannot be determined. –> DIN 53505

Specific gravity

The specific gravity describes the mass to volume ratio. An example: 1.2 g / ml = 1 millilitre (cm3) weighs 1.2 g

Tensile modulus

Tensile strength of a sealant at a given amount of elongation. (DIN EN 26927:1990)

Three-point adhesion

In case of three-point adhesion the sealant also adheres to the joint bottom with the consequence that deformation of the sealant for accommodating movement is obstructed.

Three-surface adhesion / corner joint

In case of a corner joint the two adherent surfaces of the sealant meet in the top of a triangle.

Tensile strength

Force required to break a test material when stretched.

Tooling

Process by which the sealant is pressed into the joint after processing in order to ensure adhesion of the sealant to the joint edges and to improve the visual impression of the joint surface. (DIN EN 26927:1990)

Viscosity

This term is used for the assessment of flow characteristics of fluids and pastes

Wetting

The property of a substance, e.g. primer, adhesive, or sealant to spread (flow) over the intended adherent surface. Adhesion can become effective only on wetted surfaces.