BYK USA (Wallingford, Conn., U.S.) is exhibiting Garamite-1958, a powdered rheology additive that is based on patented mixed mineral technology (MMT). This clay-based additive is organically modified to provide thixotropic enhancement to solvent-borne and solvent-free resin systems, increasing sag resistance and enhancing anti-settling and anti-separation properties. It is suitable for use in most composite applications including spray-up, SMC/BMC, gelcoat and others.

Rheology control is critical to composites applications, whether it’s providing sag resistance for resins applied to vertical molds, anti-settling for resins containing mineral fillers or anti-separation in systems containing pigments or lightweight fillers. A good rheological additive must be easy to incorporate, enabling easy processing of the material during application, and show fast viscosity recovery in the system after application.

Garamite-1958 offers many advantages over other rheological additives, including fumed silica, BYK reports. For example, it performs significantly better in filled systems, enabling high filler loadings while maintaining workable high-shear viscosities as well as optimal recovery and sag resistance even for highly filled systems. Furthermore, in these highly filled systems, Garamite-1958 provides improved anti-settling in short- and long-term storage. In many systems, the additive has also shown it is more efficiency than fumed silica and has a better viscosity recovery profile.

Incorporation of Garamite-1958 into resin systems is achievable without the high shear mixing required for fumed silica. It can be mixed directly into resin or, for the highest rheological effect, premixed into styrene and then added as a pre-gel slurry.

In addition, the bulk density of Garamite-1958 is reported to be higher than other solid rheological additives, requiring less storage space. This higher bulk density also means less dust during the formulation and mixing processes.