Stable and flexible 

Molded components are found in almost every area of life. Without molding technology, producing engine blocks, medical instruments and mini electronic components with the necessary precision would be impossible. In order to retain their new form during curing, molds need stable binding agent systems – and silanes. 

Sand and binding agent systems have long been a key component of casting production. But it was only when organofunctional silanes were introduced that the development of binding agents based on organic resins became possible. Silanes are also used here as a purely inorganic binding agent system. 

Although silanes make up no more than one percent of resin-based binding agent systems, their effect is immense. Without silanes, these casting resins often do not cure. Adding silanes, however, allows extremely high strength value to be achieved. 

The fields of use for casting technology have been added to over the years, changing the demands and requirements on the materials. The mixture of casting resins is crucial to the further processing: If the mixing ratios are wrong, the components may not bond correctly. This impairs the desired properties of the product, such as stability, elasticity, break resistance and thermal conductivity. 

Dynasylan® product range for greater stability 

Under its Dynasylan® brand, Evonik offers an extensive range of organofunctional silanes specially for the casting industry. They are perfectly tailored to the respective resin system. Drawing on decades of experience, the experts know exactly which product works best in which structure. Dynasylan® primarily ensures greater stability in the sand-based mold. Because silanes are also hydrophobic, they keep moisture out at the same time. Adding Dynasylan® also reduces the amount of synthetic resin needed, benefiting the environment.

Casting resin processes include: 

  • Croning or shell molding process 
  • Cold box process (polyurethane process) 
  • Hot box process 
  • Warm box process 
  • No-bake process (cold resin process) 
  • Silica ester crosslinking 
  • Sulfur dioxide process 

Casting is one of the industrial segments with the highest energy consumption. This is one of the reasons why the recipes are constantly modified in order to achieve optimum results at lower drying temperatures or with shorter curing cycles. Silanes can also make a vital contribution here. 

Silanes not only make the difference in organic resin systems – their diverse properties are also sought-after for the production of purely inorganic molds. Dynasylan® ethyl silicates, for example, are used as fire-resistant binding agents in fine casting, and also help to reduce drying times. The result is a standardized process that can be automated. Because silanes also allow drying and curing times to be controlled, more complex shells can be produced.

The benefits at a glance: 

  • Moisture is eliminated 
  • Resin can be stored for longer 
  • Improved initial and final strength 
  • Less resin needed