Dispersing under vacuum is practical approach to eliminate air entrapment during the dispersing process. For high viscosity liquids it is very time consuming to remove the air bubbles. It generally requires a special apparatus and the use of additives to remove the air. Dispersing under vacuum negates this time consuming step.
A Vacuum mixer has been routinely used for adhesives, inks, sealants, and color concentrate materials. With environmental regulations driving the paint industry to higher solids, low VOC products, air entrapment can be a bigger concern.
VMA-Getzmann company has three product lines for Vacuum mixing:
- CDS system
- Dispermat VL
- Dispermat VE
The CDS system is an accessory that is compatible with the Laboratory Disperser models. It consists of a sealing system for the motor shaft, a receptacle with sample container, and receptacle cover. A vacuum source is attached to the receptacle. The cover is attached to the motor shaft and is lowered onto the receptacle. A vacuum seal created by an o-ring. The cover is transparent so the operator can view the dispersion. A sealable opening is available on the cover if material needs to be added once the dispersion has started.
The Dispermat VL is designed to perform only High Speed Vacuum mixing or dispersing. The VL models share the same high performance motors used for the Lab Disperser line. The motor controls, safety features, lift motor, and optional PC interface are also shared. There is flexibility to reposition the impeller when dispersing under vacuum. The glass cover that fits over the vacuum container can be configured to meet the customer requirements. An optional scraper system is available for liquids that do not flow easily. Containers come in a wide capacity range of 1 to 60 liter containers.
The Dispermat VE is similar in design to the VL except it provides more flexibility to use different container sizes on the same vacuum mixer. The containers can be made of metal or disposable materials. The container size can range from 250 ml to 10,000 ml. A special platform and vacuum vessel are used. The platform will secure the container during the dispersing process. The vacuum vessel will cover the user the container. The vacuum sealing system is secured to the top of the vessel to create the vacuum. A scraper system is also available as an option.