In their 75 years of business, Silverson Machines has sold mixers to thousands of customers around the world. The popularity of Silverson high shear mixers can be attributed to their longevity, ease of scale up, high quality and versatility. A single Silverson mixer can perform the duties that previously required multiple pieces of process equipment. This versatility streamlines operations and eliminates the need for dedicated agitators, emulsifiers, homogenisers, and dispersers.
These advantages sees the mixers used across a range of industries for a variety of applications, showcased in the Silverson ‘How to’ video series. First launched in 2017, the series continues to grow and now has over 40 videos on different applications. The latest videos added to the series cover a range of mixing processes:
How to mix Ice Cream Mixes
In the latest video, Silverson demonstrate how to manufacture Ice Cream mixes and how a typical premix would be made.
Formulations vary widely, but ingredients usually include milk, cream, skimmed milk powder, fat including dairy fat such as butter or vegetable fat, sugars, flavours, colouring, and emulsifiers. Other ingredients, such as hydrocolloids can be used as stabilisers so it is essential that the mixing equipment is able to incorporate these ingredients into the mix.
The action of the high shear mixer disperses any powders without the formation of agglomerates and ensures that the fat and aqueous phase ingredients are emulsified and reduced to a uniform and fine droplet size, which gives the product the desired stability.
Depending on the scale of manufacturing and recipe, the premix may be subjected to further processing with a high-pressure homogenizer to obtain the smallest possible droplet size. With this process, using a Silverson mixer to create a uniform premix offers considerable reductions in process time.
How to mix Graphene
In the infancy of graphene research, Silverson mixers were used in one of the successful techniques used to extract graphene from graphite, through shear exfoliation. This process used the high shear of a rotor stator mixer to exfoliate defect-free, few-layer graphene from graphite in solvent systems or certain surfactants.
Now that research has moved on, the high shear energy of Silverson mixers is still proving essential for graphene formulations at a laboratory scale. The high shear energy ensures that the graphene is dispersed correctly throughout an entire mix so the desired end properties are achieved. GEIC (Graphene Engineering Innovation Centre) based at the University of Manchester have tested many formulations under microscopy and seen that the level of dispersion achieved with a Silverson Laboratory mixer, far outperforms conventional lab stirrers. Not only can the Silverson disperse the graphene effectively, it will also disperse any pigments, dispersants or resins in the formulation as well, completing the whole process.
One of GEICs main focuses is bridging the gap between what has been done in the laboratory and scaling up to pilot production, which is what industry needs in order to commercialise graphene products. To this end, the team at GEIC has recently purchased a production scale Silverson Batch Mixer. This has completely changed how they work on collaborative projects with their partner companies from different industries and how they can provide large scale samples for them. Since using the Batch mixer, GEIC’s production times have been reduced from several days to a few hours.
How to mix Carrageenan
In this video, viewers can see how Silverson High Shear mixers are able to overcome the common problems associated with mixing different types of Carrageenan and create an agglomerate-free dispersion. In particular, the video shows how a Silverson in-tank Batch mixer is able to disperse Carrageenan as quickly as it is added to the vessel. The high speed, high shear mixing action will rapidly draw the powder and liquid into the workhead, where any agglomerates are broken down as they pass through the precision gap between the rotor and stator. This process is completed as rapidly as possible, cutting mixing times by up to 90%.
Processing times can be further reduced with a Silverson high shear mixer as premixing of gum with other powders or non-aqueous phase ingredients is not required – this also simplifies the process.
Other advantages of using high shear mixing technology include obtaining the maximum yield from raw ingredients. As all the agglomerates in the mix are broken down by the high shear action of the mixer there is no wastage, allowing the manufacturer to reduce the gum content and their raw material costs.
You can find the entire series of ‘how to’ videos on the Silverson YouTube channel. Each video also has a corresponding application report available to read for free on the Silverson website.
If you’d be interested in a no-obligation trial to see how a high shear mixer could benefit your application, please contact: sales@silverson.co.uk
