Ever wonder how precision cleaning using CO2 got started? How did a natural gas like CO2 get turned into a high tech cleaning process for the Aerospace, Medical, Optical, Microelectronic and Hard Disk Drive markets? Several important factors have influenced and ignited the need for cleanliness in manufacturing such as concern for the environment, economic competitiveness and technology.
1990's CFC Phase-Out
Alternative Precision Cleaning
According to Mark Skaer in an article entitled The 1990s: The Decade of Refrigerant Chaos - and Change, "The 1990's was termed decade of refrigerant chaos and change. Cooling was a hot and heavy subject debated throughout the entire world this past decade. The original protocol called for a 50% reduction in chlorofluorocarbon (CFC) chemical production by 1998. The refrigerants used in well over 95% of the world’s systems were to be eventually phased out during the decade of the 90s. Engineers, wholesalers, contractors, and mechanics were all affected. So were system manufacturers, chemical producers, and component manufacturers (theNews, http://bit.ly/2AH8Ygx)."
Similarly, in the 1990s manufacturers of industrial and commercial products were also significantly impacted by the chlorofluorocarbon (CFC) phase-out, and in particular the use of CFCs in precision cleaning processes. During this time, alternative precision cleaning practices (new and old, wet and dry) were widely investigated. Many manufacturing companies were looking for a cleaning replacement that did not affect ozone depletion, maximized energy efficiency and had recycling practices.
CO2 was considered an alternative method due to many attractive properties enabling its use as a cleaning agent. New dry cleaning alternatives emerged, including centrifugal liquid carbon dioxide (CO2) degreasing, CO2 snow, CO2 composite spray, laser and plasma. However, due to the maturity, widespread availability, and knowledge of aqueous cleaning equipment and processes at the time, industry predominantly changed to wet (aqueous) cleaning practices.
Aqueous cleaning did resolve the immediate cleaning problem however, with it came a vast amount of costs: equipment maintenance, bath monitoring and maintenance, drying processes, deionized water production, wastewater management, rust and corrosion prevention, larger factory space utilization and increased labor burden. Product designs and assembly procedures suitable for CFC cleaning processes required transformation to overcome aqueous cleaning constraints such as water entrapment, drying and potential corrosion. There was also an increased piece part cleaning and drying operations prior to assembly. Therefore, the quick fix proved to be costly and manufacturers were open to looking at other technologies that cleaned as good or better than aqueous processes at lower production costs.
New Dry Cleaning
Using CO2 to clean
CO2 performed in many ways similar to dry CFC solvent spray processes and could clean applications such as optical assemblies, wire bonded assemblies, sensors and data storage devices. These markets were some of the first commercial applications CO2 technology could clean with success and could present cost savings to compete with wet processes. CO2 composite sprays are unlike other snow guns in that the sprays are relatively lean and warm with much smaller fractions of microscopic CO2 particles uniformly dispersed in a heated propellant gas, which creates better surface preparation. In these instances, wet processes could not be considered due to material compatibility, cleaning efficacy or assembly procedure constraints.
More recently, companies are concerning themselves with sustainability. They are under pressure to reduce manufacturing wastes, improve productivity, lower production costs, achieve zero discharge of pollutants into the environment, and maximize water conversion. As such, there is a need for leaner and greener methods of cleaning during manufacturing.
However, conflicts exist between the "green and lean" manufacturing model with wet cleaning practices. For example, wet practices use a lot of energy and space. Also, water resource availability has supplanted upper atmospheric ozone depletion concerns and is a major issue in many manufacturing sectors.
Since the 1990s, precision cleaning with CO2 has demonstrated significant cost-of-ownership, environmental, and performance benefits compared to conventional aqueous and solvent-based alternatives. CO2 Composite Spray™ technology has evolved and emerged as a mature and bullet-proof precision cleaning technique. This spray technology offered today provides a significant manufacturing waste reduction strategy and an attractive return-on-investment. Many manufacturing companies are implementing CO2 composite spray cleaning technology within their production operations, attracted by its many attractive features, benefits, and integration possibilities.
CO2 Composite Spray Evolution Timeline
CO2 composite spray technology was invented and patented by David Jackson, President and CEO of CleanLogix LLC, in the early 1990s. Since that time, we have steadily evolved and improved the technology. The latest version of the technology, Vector Pro™, provides the highest performance and best economy to date, and is the foundation for countless precision cleaning and hard machining opportunities in the manufacturing industry. The spray quality and efficiency of our Vector Pro spray technology has journeyed far from the initial Snow Spray technologies of the 90’s. CO2 composite sprays are highly stable and provide adjustable cleaning capacity.