Among many choices, one process stands out for its ability to produce a clean, dry part at a reasonable price: solvent metal degreasing machines
Today manufacturing engineers and plant managers face a difficult challenge when choosing among the many surface cleaning options available. Aqueous, semi-aqueous, hydrocarbon solvents, HCFCs, new fluorinated and brominated solvents are just a few of the possibilities. Among these many choices, however, one process stands out for its ability to produce a clean, dry part at a reasonable price: solvent metal degreasing machines.
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Reasons Of Failure
- Obsolescence of component (15%)
- Accidental causes (15%)
- Surface degradation (70%)
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Principles of hermetically sealed metal degreasing
The hermetically sealed metal degreasing process is the ideal technology for high quality parts cleaning. It is able to remove the most stubborn soils. It reaches into small crevices in parts with convoluted shapes. Parts degreased by solvent with cleaning, immersion and vapour come out of the process perfectly cleaned. An additional drying stage under deep vacuum recovers almost all solvent present on parts surface and in the system, reducing the consumption close to “0” (Zero Emission).
Hermetically sealed solvent cleaning machines are particularly effective with parts that contain recesses, blind holes, perforations, crevices, and welded seams. Solvent vapours readily penetrate complicated assemblies as well. Solid particles such as buffing compounds, metal dust, chips, or inorganic salts contained in the soil are effectively removed by the washing mechanical action of the machine. Firbimatic solvent cleaning machines can also be equipped with ultrasonic cleaning, which is an option, in order to remove heavy oil deposits and solid soil, by installing transducers in the treatment chamber.
The process
When ultrasonic energy is transmitted to a solution, it imparts a scrubbing action to the surface of soiled parts through cavitation – with quick build up and collapse of thousands of tiny bubbles.
Typically these modern vacuum degreasers perform the cleaning operation in a sealed chamber into which solvent is introduced after the chamber is closed. Solvent vapour then performs the final cleaning stage, and all vapours are recovered through the drying circuit at the end of each cycle.
If needed, residual solvent vapours are driven through an activated carbon recovery system, in order to reduce even further the already negligible fugitive emission. With the vacuum sealed chamber, solvent loss is reduced by more than 99,9 %. Operation is programmed and fully automated, allowing a variety of cleaning programmes, including hot solvent high pressure spraying in conjunction with mechanical action through rotating, oscillating and swinging movements of the basket.
Although Firbimatic hermetically sealed units can be more sophisticated, the superior cleaning results and the significant savings in solvent consumption have determined their undisputed success in full compliance with safety and environmental regulations.
No component has ever failed because it was too clean!
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The reasons for failure
A research made by the Massachusetts Institute of Technology of Boston by Dr. E. Rabinowicz showed that 70 % of failure reasons of lower performance of components is to be motivated by the degradation of the surfaces and that the most of such failures take origin from mechanical wearing (50 %) and corrosion (20 %).
The Firbimatic cleaning systems, are in total compliance with the international standards protecting operators and safeguarding the environment, capable to successfully treat both metal and non-metal surfaces.
These cleaning units must completely remove both organic and inorganic contaminants from the treated pieces, pinpointing from time to time the cleaning cycle most suitable for the type of component and pollutant and they must be specially effective with parts of complicated shape.
The solid dirt particles such as powders, swarfs, shavings and inorganic salts must be successfully removed as well as layers of burnt oil and other solid contaminants (oxides and lapping and polishing pastes) deposited on the component which often require on the other hand the action of ultrasonics.
Architectural features of Firbimatic modified alcohol machines
Closing system of the washing chamber: dual seal technology and commissioning tests under-vacuum at the beginning of each cycle. This allows a high level of safety (with the category of AIII solvents). The dimensioning of the distiller is to avoid additional heaters in the tanks. Thermal energy recycling of the distiller and in this way the power consumption is lower (- 30%). The heating in the distiller is indirect and electronic temperature control, this avoids pasting oil residue on the bottom of the device. The resistive elements for the heating of the distiller can be disassembled easily for cleaning.
Possibility of double distillation to evacuate the distilling oils in bypass to avoid manual intervention or stop the production consisted. Firbimatic uses only a very powerful vacuum pump for the vacuum system and drying (Multisolvent). Automatic defrosting of the cooling unit is installed on the machine. All tanks are heated through vapor distillation (tanks 1 and 2), this allows excellent cleaning and a low energy consumption. Integration of a high flow circulation pump to create turbulence in the bath of the first tank in the washing chamber.
Tanks and piping can be completely insulated. The machines are designed for use with modified alcohol and non-halogenated hydrocarbons, without modifications. versions are available DUAL SOLVENT (perc and alcohol). Circulations forced under pressure and the size of the still allow you to wash from 4 to 8 baskets / hour.
Consumption of solvent cleaning machines
For solvent cleaning machines, we can estimate an average consumption of very few liters of solvent per year if the following conditions are met:
- Correct choice of the treatment program; that is by using only the pre-loaded programs in the machine by our technicians during commissioning and start-up of production.
- Proper management of the distillation of the solvent; that is by performing the steps of distillation according to the amount of contaminant brought to machine and not manually forcing the procedure of distillation.
- Regular maintenance and cleaning; operating according to the appropriate time period indicated in the user manual.
