There is a definite trend toward the increasing use of “Glass Encapsulation Technology” in the automotive industry. In this technology a glass object such as a window is placed within a mould and an elastomer is injected around the window giving a tight sealing system. A wide variety of materials are currently used as the sealing materials in either static or semi-static encapsulated glazing systems, including a wide range of “elastomers”. New <PP/SEBS> thermoplastic elastomer compounds are being developed that are characterized by their consistent properties; including high melt-fluidity, very good surface appearance, sealing properties, and resistance to weathering.
Compound performance is highly dependent on formulation variables as well as the chemistries of the base materials. KRATON® SEBS polymers1 are block copolymers of styrene and ethylene/butylene. They function as thermoplastic elastomers which can be compounded into a wide range of hardnesses by mixing with a wide variety of ingredients like polyolefins, plasticizers, stabilizers, fillers, pigments, etc. KRATON SEBS polymers are also stable, consistent materials characterized by excellent mechanical properties and resistance to weathering, as well as by consistent thermoplastic rheology.
A new KRATON SEBS polymer has been developed for this application which has an especially improved flow and surface appearance while retaining the level of mechanical performance measured by the standard grade. This development is expected to enhance the utility of KRATON formulated compounds in glass encapsulation. These new formulation concepts are being chosen and further developed by SEBS compounders active in the automotive industry, such as Thermoplastiques Cousin-Tessier2, as part of their tool-kit to fulfil glass encapsulation requirements.