The Anticaking Effect

Imagine having a barbecue. You get some beer from the fridge, step out into your garden again and realize: The bush next to the barbecue has caught fire! You rush to get your fire extinguisher from the basement, but over the years the extinguishing powder has clumped. The result: The fire extinguisher can’t do its job and the bush has burned. As well as your steaks.

This little dramatic scene describes why anticaking agents are needed: They prevent powders from clumping. Especially powders that must be storable for a long time. Like spices, cement, powdered animal feed, milk powder, pharmaceutical powders, fertilizers, cosmetic powders, thermoplastic polymers, waxes, or, as already mentioned, extinguishing powder. 

To give powders enhanced storage stability, we have designed nano-structured silica particles called silica. This silica is a form  of silicon dioxide (SiO₂) and they provide two protective shields against caking at the same time. The first one: Placed around the much bigger particles of your host powder, silica particles act as tiny but stable spacers to prevent bridging – which is the chemical term for clumping. The second one: With its sponge-like structure, our silica can absorb moisture, water, oily liquids, and pressure to give your product additional storage stability. 

The anticaking effect is the cousin of the free-flow effect. While our anticaking products provide safe storage of powders, our free-flow products enhance the production and handling of powders. If that is your topic, find out more here.

Anticaking agents have a lot of noble jobs. One is to save lives by preventing the powder within fire extinguishers from clumping.

The storage of powders has two major enemies: any kind of wetness and pressure. While hygroscopic powders absorb moisture and clump due to liquid bridges, soft powder particles can become deformed during storage and cake.

To defeat these enemies, we offer a wide range of anticaking silica: Our precipitated silica products are labeled SIPERNAT® or ZEOFREE® while our fumed silica products are labeled AEROSIL®. Their noble job is to extend the storage stability of your powders: 

• They act as spacers between the much bigger particles of your host powder to prevent caking.
• They absorb moisture to prevent liquid bridges between particles.
• They also absorb fats and oils so that they are even suitable to extend the shelf life of waxes, for example.
• Usually, an addition of less than 1.5% is needed to achieve the desired effect.

Another plus point is: In most cases you do not need additional machines to apply our silica. You can simply mix it with your host powder in the running production process: For example, via PLOUGHSHARE®, paddle, or belt mixer. Or via polymer granulation. Or via spray tower. Our application engineers will assist you to find the most efficient way to bring your product and our product together. And they will also help you to find the most efficient ratio between silica and host powder.

And, of course, our silica does not only solve storage problems, but it’s also easy to store. It comes, for example, in 10-kilogram bags so that you will always have it to hand when you need it.

Silica is safe: The European Food Safety Authority confirmed safety of silica as food additive. 

The impact of the anticaking effect on nature can be summarized in just two words: “less loss”. Products that use our anticaking agents can not only be stored longer; they also can be used longer. Which means that less products have to be dumped due to decay. A good point for nature.  

Another good point is: Our silica agents have enormous effects on the stability of your products and our silica products are safe. That’s why they are even approved for use in food, feed, and pharmaceuticals. For example, in October 2024, the European Food Safety Authority (EFSA) confirmed safety of silica as food additive. Which means, that they are proven suitable for organic farming. Please find more facts on the safety of silica in our FAQs section.

Simply drop us a line at ask-se@evonik.com or press the contact button above. Your request will be forwarded to one of our anticaking specialists and they will get back to you as soon as possible.

Our clients, of course, will get assistance from their regional contact and from our application engineers. We are looking forward to hearing from you!