Vapor Degreasing
Encyclopedia
Vapor degreasing is a surface finishing
process. It involves solvents in vapor form to cleanse the workpiece in preparation for further finishing operations.
the contaminants on the workpiece and remove them by dripping off the part. A basin of solvent is set up with a heating coil to bring the solvent to boil
. As the solvent evaporates it rises to the fill-line in the chamber, above which is air with a much lower density than the solvent. This contains the vaporized solvent in a closed space where the workpiece is placed. The solvent condenses on the more frigid workpiece and the now liquid solvent dissolves the greases on the part. With the impurities contained in the liquid beads, the solvent runs off the part. Some systems are designed to capture and reclaim this solvent, making the process much more economical.
Other adaptations to the simple system include:
Surface finishing
Surface finishing is a broad range of industrial processes that alter the surface of a manufactured item to achieve a certain property. Finishing processes may be employed to: improve appearance, adhesion or wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance,...
process. It involves solvents in vapor form to cleanse the workpiece in preparation for further finishing operations.
Process
The acting principle behind the vapor degreaser process is that the solvents will dissolveDissolution (chemistry)
Dissolution is the process by which a solid, liquid or gas forms a solution in a solvent. In solids this can be explained as the breakdown of the crystal lattice into individual ions, atoms or molecules and their transport into the solvent. For liquids and gases, the molecules must be compatible...
the contaminants on the workpiece and remove them by dripping off the part. A basin of solvent is set up with a heating coil to bring the solvent to boil
Boiling point
The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid....
. As the solvent evaporates it rises to the fill-line in the chamber, above which is air with a much lower density than the solvent. This contains the vaporized solvent in a closed space where the workpiece is placed. The solvent condenses on the more frigid workpiece and the now liquid solvent dissolves the greases on the part. With the impurities contained in the liquid beads, the solvent runs off the part. Some systems are designed to capture and reclaim this solvent, making the process much more economical.
Other adaptations to the simple system include:
- Several tanks for solvents and rinsing
- Having a solvent spray to coat the workpiece prior to entry into the chamber to speed up the process and to allow for more complex parts to be cleaned. The spray must be below the vapor line.
- Vacuum degreasers.
Benefits
- Can be used on electronic parts to remove excess oilOilAn oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
, greasePetroleumPetroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
, waxWaxthumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...
and other non-water soluble particles because water is not used. - Used where water-based system are impractical.
- Cleans and prepares part surfaces for various finishing processes like paintingPaintingPainting is the practice of applying paint, pigment, color or other medium to a surface . The application of the medium is commonly applied to the base with a brush but other objects can be used. In art, the term painting describes both the act and the result of the action. However, painting is...
, weldingWeldingWelding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...
, solderingSolderingSoldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...
, and bonding. - Issues of part oxidation and water spotWater spotA water spot is an area of dried mineral deposits left on a surface after being allowed to air dry. Water quality, specifically the amount and type of minerals in the local water supply as measured by the total suspended solids or TSS test and other mineral levels such as sodium level, has a big...
s are not present. - With vacuum degreasers, there is no solvent emitted. However they have a high cost and low production rate.