The reclamation of waste products such as foods and chemicals, has for a long time been a standard application for High Shear mixing. Silverson Machines founder Nate Rothman wrote a piece on the treatment of waste food products for humans and animals, organic waste and even chemical waste products back in 1977.
Since then Silverson have been helping customers to rework and reclaim confectionery, bakery, paper and other waste products to help reduce production costs. Today, reclamation of waste is becoming as much about companies wanting to be more sustainable and reduce their excessive waste as it is about saving money.
The increasing want and need for companies to improve their sustainability and reduce their impact on the environment has opened up a whole new world of inventive and innovative applications for high shear mixing.
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Companies are no longer just trying to reuse and recycle, over the past few years Silverson have been increasingly seeing new applications which help to address some of the big issues in the fight against climate change and build a more sustainable world.
In this article, we look at waste reclamation and the recycling of excess product, as well as some of the new and ground-breaking applications for which manufacturers are choosing high shear mixing equipment.
High Shear Mixing Application: Battery slurries for electric cars
With the production and sales of petrol and diesel cars in the UK to cease by 2030, focus is being shifted towards the production of electric vehicles. These electric vehicles (EVs) receive energy from a battery which is converted into power by an electric motor.
These batteries can consist of several different components and will vary between manufacturers, one customer that Silverson has assisted was creating a battery slurry for hydrogen fuel cells. This slurry consisted of carbons, binders, propanol and ethanol along with other materials.
These batteries are used to store energy received from charging stations and the charge of the battery affects the mileage and distance the EV can travel, so it is important for manufacturers create the best possible batteries for their vehicles.
The slurry materials and processing poses several challenges, but most importantly, the slurry materials must be reduced to the finest possible particle size with maximum homogeneity. It is important that the process is repeatable and care must be taken not to over-shear the materials as this can impact the finished electrodes.
Using a high shear mixer, materials can be uniformly dispersed and reduced down to a fine droplet size. This pre-mix can then be fed easily through colloid mills or high pressure homogenisers to obtain the sub-micron particle size needed, speeding up the production process and avoiding blockages to processing equipment.
High Shear Mixing Application: Replacing chemical fertilisers
Impacts from human activity on land and in water can profoundly influence ecosystems. Soil erosion is one the many problems facing ecosystems which customers and manufacturers are looking to reverse and ultimately solve.
Part of this involves creating and producing new products which are organic and environmentally friendly to replace their chemical counterparts. In the case of fertilisers, chemicals fertilisers when used will eventually end up in water systems. To eliminate this manufacturers are working towards creating effective natural, plant-based solutions including the use of materials such as seaweed.
One of the advantages of using seaweed in fertiliser is that it makes it phosphate based rather than nitrate based and is therefore better for the soil and helps to maintain the long-term health of the soil.
Again, the reason that high shear is necessary for this application is that the seaweed must be disintegrated down into finer pieces, almost to a slurry, before being moved on for further processing, something with conventional mixing equipment is just not capable of.
To create the fertiliser, seaweed in its raw, harvested form, is added slowly into water while a high shear mixer carries out the initial disintegration. Once the seaweed has been reduced down, it is circulated through an high shear In-Line mixer to further reduce the size of the seaweed. With the combination of initial disintegration and refinement, seaweed pieces can reduced down to sizes of 1mm.
High Shear Mixing Application: Decontaminating soils
As well as using less harmful fertilisers on our soils, manufacturers are now looking for solutions to reverse the damage already done to soils through contamination and pollution, in order to secure food security for future generations.
Silverson has worked with one particular company who are developing a new product capable of degrading specific pollutions in soils so that the affected soil can be used again for planting. The product can be used to clear up hydrocarbons, which are found in crude oil, natural gas, and coal.
The decontamination is done using a specially selected fungus or bacteria capable of degrading the pollution. Before these can be spread they have to be encapsulated and this is done by mixing a binding/suspending agent, in this case alginates, into water.
A high shear mixer capable of effectively incorporating the alginates into water without the formation of agglomerates was essential for the development of this product. Long mixing times and over-shearing the product could affect the fungus viability and the viscosity of the product was very high.
Effectively incorporating the alginates was proving challenging for their previous conventional mixing equipment taking several hours at a time. The centrifugal force created using a high shear mixer draws the powdered alginate straight into the mixing workhead, eliminating agglomerates before they are able to form and shorting mixing times considerably.
High Shear Mixing Application: Vegetal glue to replace chemical equivalents
Replacing traditional chemical products with plant-based or vegetal alternatives is also expanding into other industries such as glues, in this case of this application for chipboard and wood panels. Silverson has recently helped a company specialising in the development of viable alternatives to fossil-based products by using new techniques to create renewable raw materials from vegetable proteins.
This application involves using a vegetal protein, which is supplied in fine particle powder form and is made from ‘residual oilcakes', the by-product of the vegetable oil making process. The vegetal protein for this glue uses the by-product of the rapeseeds used for making Colza oil, helping to minimise waste in the vegetable oil industry.
To manufacture the glue the protein is incorporated into water, although the final viscosity of the product was not particularly high (around 1000 – 1500 cps, similar to the viscosity of glycerine) the mixture was incredibly sticky.
It was important for the manufacturer that the mixing equipment was able to quickly incorporate the powder, to avoid it rafting on the surface. They had also had problems with localised mixing, the positive mixing action of a high shear mixer kept the product moving around the vessel continuously, eliminating this problem.
High Shear Mixing Application: Alternative proteins
Eating less animal-based products can help to reduce pressure on forests and land used to grow animal feed and house livestock. In recent years there has been a shift from consumers towards plant-based products such as non-dairy milks and vegan alternatives with more products than ever now on the market. Silverson have been helping customers who are looking to produce new products which try to replicate the texture and taste of meat without the environmental impact.
Working with plant-based meat producers high shear mixing equipment has been helping them create the artificial blood and juices that go into their ‘meats'. This involved incorporating and deagglomerating their preparatory powders and thickening agents into their mixture as well as reducing these powders to the desired particle size for the correct mouthfeel.
High shear mixing can also offer advantages in the dispersion and hydration of proteins, starches and other functional ingredients used to obtain the desired texture and stability.
High Shear Mixing Application: Reclamation of excess food products
One way to reduce our impact on the environment is by using less and making more of what we already have. This is feeding through to production lines, especially in the food industry with more manufacturers making use of off-cuts and excess product. This in turn reduces their wastage and saves them money on raw material costs.
High shear has long been used for the reclamation of confectionery, with the high cost of raw materials such sugar and cocoa encouraging manufacturers to reclaim and rework “off-spec” product. But now this is expanding into other areas of the industry with cheaper processing costs, for example bakery products and excess pasta.
The reclamation of these products works in a similar way; the excess product is incorporated into a liquid, usually water, and reduced down into a slurry. This slurry can then be used in subsequent batches of the product. For this process to be effective, the mixing equipment must be capable of disintegrating solid material down into a homogenous mixture which can be forwarded on for further processing.
The clarification and recycling of oil waste is another innovative way in which the food industry is trying to combat excessive wastage. In a recent case, a Silverson customer wanted to manage the amount of oil they were using by prolonging the usable life of vegetable oil, with the goal of eventually reducing the wastage to zero.
The vegetable oil, which was being used in the batch frying process for their snack product, could be reused by incorporating a food grade powder which would reduce the Free Fatty Acid levels to below a threshold where it was safe to reuse.
An impeller was unable to prevent a thick residue building up in the vessel due to the limited movement it was creating in the tank and this was affecting the ‘cleaning' of the oil. The centrifugal force created using a high shear mixer, kept the product recirculating throughout the entire vessel while incorporating the powder.
Once a high shear mixer was incorporated into their process line the amount of new oil being purchased by the company was reduced from 30,000 litres every week to 30,000 litres every two weeks, cutting their processing costs by 50%.
High Shear Mixing Application: Graphene – the new wonder material
Graphene is a two-dimensional material consisting of a single layer of carbon atoms arranged in a honeycomb structure one million times thinner than a sheet of paper. It is the strongest known material – 200 times stronger than steel, it is highly conductive of both heat and electricity, and yet lightweight and flexible, making it a desirable material for use in many industries including aerospace, engineering, digital electronics, biomedicines, transport and energy.
Graphene was first isolated from graphite using a sticky tape method – removing flakes from a piece of graphite using a piece of sticky tape. By repeatedly separating the graphite fragments, flakes just one atom thick were created.
Although this method is still used in laboratories it cannot be replicated on a larger scale, and research into ways of isolating graphene in sufficient amounts to be commercially viable has been ongoing for some years.
A process called exfoliation – high shear mixing of graphite in a suitable solvent – has been proven to isolate small but significant amounts of graphene. High shear mixers are necessary for this application as they are able to reduce the graphite down to useable defect-free graphene.
The above are just some of the new applications relying on high shear to make them a reality. Other new applications include creating sustainable packaging from paper pulp and the creation of a cellulose plastic replacement product as a substitute for plastic bags.
Find out more about Silverson High Shear Mixing
Silverson Machines Ltd
- 01494786331
- sales@silverson.co.uk
- Waterside Chesham Buckinghamshire HP5 1PQ GB
About us
For more than 75 years Silverson has specialised in the manufacture of quality high shear mixers for processing and manufacturing industries worldwide.
With customers in over 150 countries, and serving industries as diverse as food, pharmaceuticals, cosmetics, luboils and petrochemicals, Silverson has become the world leader in the field of high shear mixing. Time after time, companies specify Silverson mixers as the “standard” equipment for their manufacturing process.
The key to this success is based on the professionalism and commitment Silverson shows to each of its customer’s needs. Whether supplying machines from its standard range of mixers or designing equipment specifically to meet an individual customer's requirements, quality is guaranteed.
With a customer base that includes many of the world’s largest companies, Silverson is constantly at the forefront of new technologies. Developing and applying new high shear mixing techniques to meet these needs, Silverson has the experience, knowledge and commitment to both quality and service to solve today's mixing needs and those of the future.
A truly international company, Silverson is represented by a network of associated companies, distributors and agents in over 50 countries, serving North America, Europe, Asia, Australasia, South America and Africa.
What we do in a nutshell
Silverson Machines are world leaders in the design and manufacturing of high shear mixers as well as specialising in Powder/Liquid Mixers, Hygienic Mixers and Disintegrator/Dissolvers. Our technology has many applications and spans food, pharmaceuticals, cosmetics, chemicals and the lube oils industries.
Where we supply to
UK Ireland, Europe, Africa, Asia, Australia, South America, North America
Industries we supply to
Chemicals, Food and Beverage, Pharmaceutical Cosmetics Toiletries, Plastics and Rubber
