Mixing Tips

Gums & Thickeners – How to Avoid Agglomerates

Suppliers of gums and thickening agents will advise you to sprinkle the powder slowly on the liquid surface to reduce the formation of lumps and fisheyes, because the washing action of conventional agitators cannot readily break these down, resulting in inconsistent product quality and poor yield.

With a Silverson High Shear mixer the opposite approach should be taken; the powder should be added to the liquid all at once, in a controlled manner but as quickly as possible. The mixing/shearing action of the rotor/stator workhead rapidly disperses and hydrates the powder before the viscosity starts to increase, ensuring an agglomerate-free solution is achieved with maximised yield and consistent, repeatable results.

Case Study: Gum Solution Made 40x Faster with High Shear Mixing
Dispersing Gums & Thickeners

Blending Liquids of High and Low Viscosity

Achieving an optimal blend of liquids with varying viscosity levels requires a strategic approach. When mixing liquids of high and low viscosity, it is recommended to start with the low-viscosity liquid and gradually introduce the higher-viscosity liquid. This sequence offers several advantages, including enhanced energy efficiency and improved mixing performance.

By initially adding the low-viscosity liquid, the mixer can operate at a more efficient level since it doesn’t need to be specifically sized to handle the highest viscosity component. This approach optimises the mixer’s performance and reduces the overall energy consumption during the blending process.

When incorporating colouring or dye into the mixture, it is advisable to add it last. This deliberate sequencing serves as a visual indicator, allowing you to visually assess the consistency of the blend.

How to Blend Liquids of Varying Viscosities

Optimal Particle Size Reduction

When dispersing powders where a degree of particle size reduction is required, best results can be obtained by adding the powder to the smallest possible volume of liquid. This focuses the mixer’s energy on dispersing and milling the powder rather than moving the full volume of the batch, and the concentration of powder provides attrition which accelerates the reduction of particle size. Once the required particle size is achieved the remaining liquid can be rapidly blended into the mix using the Silverson mixer.

Rapidly Mill Materials to a Low Micron Size in a Single Operation

Efficient Emulsion Preparation

When forming an emulsion, it is crucial to add the dispersed phase to the continuous phase correctly. While this might be less critical at laboratory scale, it becomes essential when dealing with larger volumes, a common problem when scaling up. 

Silverson In-Line mixers mixers are ideal for the preparation of emulsions, including water-in-oil (W/O), oil-in-water (O/W), and water-in-oil-in-water (W/O/W) emulsions. Adding the dispersed phase just prior to the In-Line mixer will ensure an instant emulsion, maintaining uniformity and stability throughout the process.

Instant Stable Emulsions

Need to Increase Production, but Limited on Space and Budget?

Adding a Silverson In-Line mixer to your existing process can reduce mixing times by up to 90 percent, allowing you to substantially increase productivity without the need for additional vessels or other capital equipment.

Maximise Production with up to 90% Faster Mixing!

Maximise the Efficiency of Your Milling Process

Where conventional milling equipment is being used, pre-milling the product with a Silverson mixer will create a uniform premix that will pass through the conventional mill at a much faster rate, because media mills work best when fed with a product of a consistent and low particle size. In many cases the Silverson mixer can dispense with the need for conventional milling altogether. Silverson offers a range of mixers including single and multistage In-Lines and the Multishear Mill, designed for processing even the hardest materials such as pigments, dyestuffs, filter cake, titanium dioxide, etc.

Improve the Performance of Your High-Pressure Homogeniser

High-pressure homogenisers are costly to buy and operate; they are maintenance intensive devices and have a relatively low throughput. Processing product through a Silverson Homogeniser mixer prior to the high-pressure homogeniser produces a low globular size, uniform premix, which will pass through the homogeniser at a much faster rate, normally in a single pass. In many cases, the low globule size produced by the Silverson mixer can eliminate the need for a homogeniser altogether.

Silverson Mixer/Homogenisers

Trouble Scaling Up from the Laboratory to Full Production?

Do you find it difficult to replicate the results from the pilot plant? The key to successful scale-up is to use equipment that matches as closely as possible the production plant. Many suppliers of laboratory mixers are specialists in small units, but do not produce large scale equipment. Silverson’s laboratory mixers are scale models of their production counterparts, and will give identical end results, enabling you to replicate in the laboratory, the performance of every mixer in Silverson’s product line with accurate and repeatable results.

Laboratory Mixers

Looking to Eliminate Aeration from Your Mixing Process?

Silverson In-Line mixers offer aeration-free operation. The mixer, pipework and vessel form a closed system, and the flooded suction provided by the self-pumping In-Line mixer cannot introduce air into the product. This makes it ideal for the processing of aeration-sensitive products such as shampoos and detergents.

Aeration-Free Mixing

Dispersing Powders without the Need to Premix

Unlike eductor funnels and other conventional powder/liquid mixing systems, when using a Silverson Flashmix, ingredients don’t need to be premixed before addition to the feed hopper. For example, suppliers of gums and thickeners sometimes advise premixing them with other powders to reduce the formation of agglomerates in conventional processes. This is not necessary with Silverson powder/liquid mixing systems, because the high shear rapidly incorporates the powder into the liquid and shears any agglomerates down, ensuring complete dispersion and hydration of the powder and maximised yield.

Powder/Liquid Mixing Solutions

Accelerate Your Solubilisation Process with a Silverson In-Line Mixer

If you are solubilising rubbers or polymers into solvents, oils or asphalts, your in-tank agitator might incorporate the material efficiently, but the washing action of the agitator cannot reduce the solids in size so it takes a long time to completely solubilise the polymer. A Silverson mixer will accelerate the process as the liquid and solid materials are subjected to intense high shear as they pass through the workhead, reducing the particle size and so exposing an increasing surface area to the surrounding liquid. The combination of finely reduced particle size and vigorous mixing rapidly solubilises the polymer or rubber. Silverson offers a range of equipment to suit all batch sizes and types of polymer, including systems that can handle whole bales of material into the solvent, eliminating preliminary chopping and grinding stages.

High Speed Solubilisation of Resins

Optimised Order of Ingredient Addition

A Silverson High Shear mixer can simultaneously carry out a range of mixing tasks – disintegrating, dissolving, emulsifying or homogenising, etc. – many products can be manufactured in a single step using a Silverson mixer. Where gums and thickening or stabilising agents are included in the formulation, add these last. This allows other powders in the formulation to be dispersed easily while viscosity is low, and prevents degradation of structured products when adding ingredients that may affect pH.

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