Wacker Chemie AG

WACKER Showcases All-Round Additive for Thermoplastics

WACKER, the Munich-based chemical group, will be attending K 2010, the 18th International Trade Fair for Plastics + Rubber, with a high-performance additive for compounding thermoplastics. Sold under the name GENIOPLAST® Pellet S, this silicone product can be used with all conventional thermoplastics. It works in two different ways: first, by improving the surface properties of the plastic article and, second, by making compounding and shaping of thermoplastics more efficient and economical.

GENIOPLAST® Pellet S is a highly concentrated silicone additive in pellet form. Its active ingredient is a non-crosslinked, ultra-high-molecular, linear silicone polymer (silicone gum). The carrier material for the silicone is a pyrogenic silica which has been tailored for this purpose. Since this silica is compatible with all thermoplastics, the additive can be used to compound every type of thermoplastic – unlike conventional silicone masterbatches.

The silicone active ingredient imparts a smoother surface to thermoplastic polymers. This means that GENIOPLAST® Pellet S also enhances the polymer’s scratch and abrasion resistance. These surface-enhancing effects come without undesirable side effects. Basic polymer properties, such as tensile strength, hardness and heat distortion, as well as printability and weldability are not impaired. Adding GENIOPLAST® Pellet S to mineral filled thermoplastics additionally boosts the notched impact strength and elongation at break. The additive also acts in synergy with flame-retardant fillers.

The additive is easy to meter and is readily incorporated, also along with any mineral fillers, into thermoplastics. The silicone active ingredient improves filler dispersion and its friction-lowering properties make compounding easier. Thus, GENIOPLAST® Pellet S acts as a compounding auxiliary. By lowering energy requirements and boosting throughput, it offers plenty of scope for cutting down on costs.

The additive also benefits injection molding by improving the flow properties of the thermoplastic melt. This not only boosts mold filling and thereby leads to less scrap. Also, cycle times become shorter because more material can be injected into the mold per unit time. Finally, the molded parts are easier to demold, as well. The overall effect of using GENIOPLAST® Pellet S in injection molding, then, is to cut the unit costs. Extrusion, e.g. production of cable sheaths, is another processing method that benefits from incorporating the additive into the compound – again, the additive enhances the process and lowers costs.

Thermoplastic polymers modified with GENIOPLAST® Pellet S are already finding great success in practice. Key applications include cable sheaths and molded parts for automotive interiors, such as dashboards and door panels.

GENIOPLAST® Pellet S has a comparatively high silicone content of 65 weight percent, far above that of masterbatches. This renders the product highly efficient: just 0.1 to 1 weight percent is sufficient to bring about the process improvements mentioned above. And additions of 1 to 5 weight percent are sufficient to enhance the properties of plastic articles.

Visit WACKER at K 2010 in Düsseldorf, Hall 06, Booth A10.

Small cylindrical pellets with a huge effect: GENIOPLAST® Pellet S makes it easier to produce and process thermoplastic compounds and helps to improve the surfaces of the plastic articles made therefrom. (Photo: Wacker Chemie AG)