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During the die-casting of light metals, any direct contact between the hot liquid molten metal and the steel casting mold needs to be avoided. In addition, the mold must be cooled quickly after each casting. These two points are crucial to the process. Why? If the molten metal reacts with the casting mold steel, it will form an alloy that prevents release. If the casting mold is too hot (or too cold), its dimensions will change and the cast parts will either have the wrong geometry or will block the machine.

To avoid this, cooling release agents are used. These compounds are normally based on mixtures of water for cooling and emulsified mineral oils or waxes to ensure a sufficient release barrier between the mold and the molten metal. The oil-water-mix is stabilized by emulsifiers such as surfactants. But, oils and waxes actually repel water from the surface and, as a result, limit the effectiveness of the cooling.

Another layer of complexity is added by the fact that liquids are affected by the Leidenfrost Effect when they are applied to hot surfaces. In our case of light metal die-casting, this means that the cooling release agents — when applied to cool down the hot mold — form droplets that bounce across the hot mold surface instead of forming the required release barrier. This is caused by the evaporation of the liquid during contact with the hot mold, which leads to the formation of an insulating vapor layer around each drop.

Family owned GELITA, with more than 140 years of protein research experience, has an unparalleled legacy of developing new concepts to address a wide range of technical applications such as this.

The company has created an innovative and patented solution called NOVOTEC® CR800. Instead of oils, waxes and emulsifiers, proteins are used to improve the release process. Much like the revolutionary NOVOTEC® CL800 — a new additive for metalworking fluids — the company has created this new liquid product that’s based on a novel class of functional proteins. Presenting a paradigm shift in a wide range of domestic and industrial applications, GELITA scientists are changing surface technology from hydrophobic to hydrophilic.

The new additive for mold release agents, NOVOTEC® CR800 forms thermodegradable layers of hydrated protein chains that facilitate cooling by reducing the Leidenfrost Effect. The thermal decomposition of the proteins generates a reductive atmosphere, which takes oxygen away from the metal surface. Thus, the cast parts have a much cleaner and better surface as the cooling is more efficient and the release agents undergo controlled degradation during each molding leaving only a small amount of water-soluble residue instead of cracked oil. Subsequently, cast parts can then be processed via bonding, welding, painting or coating without the need for intensive cleaning.

By solving the three major issues of light metal die-casting — speed (better cooling performance), safe release (elongated mold lifecycle) and less residue (higher surface quality) – NOVOTEC® CR800 can be used as a versatile tool to improve the performance of water-miscible release agents and pave the way for products dedicated to modern micro-spray devices.

Field trials in the production of crankcases showed that the use of a NOVOTEC® CR800-based cooling release agent accelerated the production speed by up to 20% and reduced water and chemical usage by up to 30%. It is also worth to mention that all cast parts in this trial passed standard controls such as X-Ray, with positive results.

In a nutshell, NOVOTEC® CR800 lays the foundation for new, sustainable and economical cooling release products that allow shorter production cycle times, enable significant water and wastewater savings, and improve the overall health and safety of employees, quality of cast parts and the lifecycles of machines and tools.

Want to learn more about NOVOTEC® CR800 and other groundbreaking innovations? Please don’t hesitate to contact us.