Mixing powders into liquids can be a challenging task, one which only becomes more difficult when using the incorrect mixing equipment. A French company mixing Xanthan Gum, CMC, Carbomers and pigments for different products were unaware how simple it can be to incorporate these powders before switching to Silverson.
Fast impeller anything but fast - mixing times of 24 hours!
Previously, the company had been using a fast impeller to incorporate the aforementioned gums and thickeners. This process was anything but fast, in some cases, the impeller was left to run for an entire day to complete the mix! Despite these very long mixing times, the resulting mix was of poor quality with lumps of un-hydrated, undispersed powder still present. This meant further lengthening process times with a filtration stage to remove the agglomerates.
After coming across the Silverson YouTube channel, and watching our ‘How to’ video on dispersing Xanthan Gum the company got in touch with their nearest sales office - Silverson France. Our mixing experts knew from prior experience that dispersing these powders should not be this difficult or be taking such a long time for a poor-quality product. After discussing with the company what they wanted to achieve, a Flashmix Powder/Liquid mixer from our demonstration fleet was sent to their facility so that they could carry out trials on-site
Xanthan dispersed in 35 minutes during trials
The company wanted to reduce their mixing times and eliminate agglomerates when incorporating a range of different powders for products including descaler and hand sanitisers. Ideally, they wanted one mixer that could disperse all of these powders effectively at different volumes, from 3500 litres up to 27000 litres.
Trials were run to test the effectiveness of the Flashmix dispersing the following powders:
- Xanthan Gum into Vinegar and into Water
- Methylcellulose and Hydroxypropyl Methylcellulose polymers
- Sodium Carbonate
- Natural pigment (Walnut stain)
A trial was run at the company's facility using a Flashmix FMX50 Powder/Liquid mixer fitted with General Purpose Disintegrating Head. The company tested the mixer on a number of its products, incorporating the powders listed above, and using different-sized vessels to test the capabilities of the mixer across a range of volumes and powders.
The first trial involved dispersing 17kg of Xanthan Gum into 3500 litres of Vinegar. With the FMX50 all of the Xanthan Gum was introduced into the mix within 50 seconds. The mixture was then left to recirculate for 35 minutes. After this time the mixture was to the exact standard required, with no agglomerates so there was no filtration stage needed. This reduced the mixing time by over 23 hours compared to the fast impeller!
Why the Flashmix?
The Silverson Flashmix was able to produce these great results because, unlike many powder/liquid mixers, which use vacuum to pull in powders, the Flashmix literally forces powder into the liquid stream. The specially designed pumping rotor creates very high liquid flow rates, driving liquid through the workhead and then pumping it back into the process vessel. This means that when the powder feed valve is opened, the powder passes straight into the high shear rotor/stator workhead, where the powder and liquid are intensively mixed, allowing no time for agglomerates to form. Bypassing the rotor/stator workhead is impossible, so all powder is hydrated and uniformly dispersed throughout the mix, achieving the full yield and thickening effect.
The Flashmix was successful in all the applications tested and produced great results. Not only did it substantially reduce the mixing time, but it also saved additional time associated with cleaning. The Flashmix was cleaner than the impeller as there was less dust and the bags were more manageable for the operators to handle as the powder could be added at ground level. Because of the huge improvements to their process, the company purchased the Flashmix immediately after the trials.
Take a look for yourself - Agglomerate-free 2% Xanthan Gum Solution in 10 minutes
Silverson offers a range of mixers for the dispersion of gums and thickening agents, the selection of which is dependent on factors such as batch size, viscosity of the end product and the percentage and grades of gum used. In the video below, see how a Silverson High Shear in-tank Batch mixer is able to create a 2% Xanthan Gum Solution in 10 minutes: