Effective and gentle drying in a vacuumJanuary 2017
Gentle vacuum drying for non-flammable and flammable solvents
Vacuum drying chambers are used in many areas of science and industry in order to dry heat-sensitive materials quickly and effectively.
Conventional drying processes can damage heat-sensitive materials such as food, medication, chemicals or electronic components, or change their product properties. Carrying out the drying process in a vacuum drying chamber reduces this risk to a minimum. Vacuum drying is one of the most effective and gentle drying methods available. The aim of this method is to gently dry a high-grade product that contains water or a solvent without endangering the materials. Drying in a vacuum drying chamber is particularly recommended for compounds containing flammable solvents. Due to the oxygen in the air in particular, these compounds often develop an explosive atmosphere during the drying process. This is prevented when dried in a vacuum drying chamber. Vacuum drying also minimizes the risk of scaling or oxidation residue.
In the vacuum-drying process, the material to be dried is subjected to a reduced pressure environment, which reduces the boiling point and aids evaporation of the water or capillary transport. The targeted supply of heat and pressure control optimizes the drying process. Another positive effect is the low energy costs, as the vacuum makes it possible to dry materials at very low temperatures.
Huge range of applications
Typical applications for vacuum drying chambers include drying heat-sensitive products, semiconductors, and electronic components such as connectors, switches, and relays after cleaning. The chambers are also used to condition materials such as plastics and resins, as well as for certain aerospace tests, for fast and gentle drying of powder or granulate, or for drying materials with low heat conductivity. Further applications include drying tissue samples in the fields of cancer research and pathology, drying easily decomposable materials such as pigments, proteins, or vitamins, or drying seed materials such as cornmeal in order to eliminate moisture.
“Without vacuum drying chambers, it would be difficult or even impossible to dry electronic components – which need to be dried at a lower temperature – or PCBs, which are fitted with lots of different parts,” says Achim Schwörer, BINDER Sales Representative for Baden-Württemberg.
Vacuum drying chambers are also used to dry small components. “One of our customers, for example, uses a BINDER vacuum drying chamber from the VD series to dry riser tubes for nasal sprays,” explains Achim Schwörer. “The extremely thin plastic tubes are cleaned and then need to be dried again. In a normal forced convection drying chamber, it wouldn't be possible to completely remove the moisture from the tubes.” The same technology is applied to medical equipment. The tiniest implants and screws are cleaned in special baskets and then dried in a vacuum drying chamber. The optical industry also makes use of this technology and dries heat-sensitive lenses at low temperatures in the chambers in order to prevent water spots on the surface. “The best drying results are achieved in a vacuum – in a normal forced convection chamber, the small parts either wouldn't dry at all or it would take a very long time,” says Achim Schwörer.