The free-flow effect

Has your soup or barbecue marinade ever been ruined by a big clump of chili powder? Well, then you have already been a victim of a product that does NOT use the free-flow effect. The free-flow effect ensures an exact dosage of powders. As well as hassle-free production. That’s what makes our free-flow products an effective invisible helper for all powder producers.

Whether it is spices, instant beverages, milk powder, detergent powder, powdered animal feed, polymers, or pharmaceuticals: Powders tend to clog. The smaller the particles are the more likely it is that they will “glue” together which prevents them from free flowing. That’s one of the laws of nature. 

So, we use chemistry and physics to beat the laws of nature: Our free-flow products are so-called silica which means that they are made of silicon dioxide (SiO₂). They are much smaller than the host powder. Once mixed the silica particles cover the surface of the host powder and act as a spacer. Your powder flows continuously and effectively – that’s what chemists call the free-flow effect.

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

The free-flow effect ensures an exact dosage of powders. For example, when spreading fertilizers.

Evonik offers a wide portfolio of free-flow products: SIPERNAT® and ZEOFREE® are our main brands for precipitated silica, our main brand for fumed silica is named AEROSIL®. What all our free-flow products have in common: They enable effectiveness in three dimensions:

• Free-flowing powders can flow faster, so our products offer faster production rates and an increased throughput.
• Your host powder covered with silica is less sticky to your production equipment leading to reduced production downtime and maintenance costs.
• The free-flow effect is appreciated by industrial and end consumers, because free-flowing products are easier to dose – think of our example of the soup or barbecue marinade …

Some more good news: In most cases you do not need extra machines to apply our silica. Simply mix it with your host powder in the running production process: For example, via ploughshare, paddle, or belt mixer. Or via water bath for polymer granules. Or via spray tower. Our application engineers will help 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. Usually, an addition of less than 1% is sufficient to achieve the desired effect.

Finally, you can store our silica easily: for example, in 10-kilogram bags so that you will always have it to hand when you need it.

Free-flowing powders, like flour, can flow faster, so our products offer faster production rates and an increased throughput.

Our silica agents have great effects on the properties 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. Additionally, our silica products received an OMRI Listed® Certification. Which means, that they are proven suitable for organic farming. Please find more information on the safety of silica in our FAQs section. 

Another positive aspect is that a host powder covered with silica is less sticky to your production machinery. That saves maintenance costs and wastewater too.

Simply write an email to ask-se@evonik.com or press the contact button above. Your request will be forwarded to one of our free-flow specialists and they will get back to you as soon as possible.

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