Low-Shear Handling of Suspensions with an Intermittent Dispersing Phase

10.05.2021
Powders in the conventional sense are known as solids. Their classic manufacturing process is called Powder Compaction: Dry powders are compacted with a pounder to form a solid unit (a disc or other form). Finished products are i.e. eye shadow or blush.
Low-Shear Handling of Suspensions with an Intermittent Dispersing Phase

2-component filling pump ViscoDuo VM HD. (Image source: ViscoTec Pumpen- u. Dosiertechnik GmbH)

However, in some manufacturing processes these powders are formulated in a liquid phase. This often results in complex fluid characteristics. The behavior is sometimes rheopex, i.e. shear-thickening over a period of time. Shear causes the solid component to compress, the liquid is extracted, and the product can therefore no longer be dosed. The solution: These rheopex fluids or liquid powders can be dosed using a low-shear dosing method. The ViscoTec endless piston principle is particularly advantageous for this application. It allows continuous and low-pulsation dosing and filling.

After the actual dosing process, the intermittent dispersing phase is evaporated - the suspended solids form a solid structure. In this way, color gradients can be achieved in addition to shapes, such as lettering or patterns. Different products can also be combined.

The ViscoDuo VM HD, a 2-component Hygienic Dispenser, is used to combine different products. The mixing ratio of two material components can thus be flexibly adjusted.

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