Efficiency is Trendy
I attended this year’s parts2clean show to see what’s new and what the current trends are in the industrial parts cleaning industry. There was one word I heard everywhere: efficiency. No doubt, users of industrial parts cleaning equipment want to—and often have to—decrease costs per unit cleaned in order to remain competitive. In almost all discussions specifications for particulate and film-like cleanliness played a role. The results to be met are more or less high, depending on the industry sector involved. So on the one hand, more cost-effective processes are required, and on the other hand, increasing cleanliness specifications have to be fulfilled reproducibly and in shorter cycle times.
A prerequisite for mastering this balancing act is a cleaning system and process that is adapted to the given cleaning task in the best possible way. In wet-chemical cleaning processes, which are frequently employed in the metalcutting and forming industry from coarse to fine cleaning, this involves the selection of a suitable cleaning agent, a corresponding machine and process engineering and bath maintenance.
The effectiveness and efficiency of the chosen agent critically depend on its dissolving capacity. A guideline for the selection is the “like dissolves like” principle. Water-based cleaning agents are available in neutral pH, alkaline or acidic formulations. They are also employed if, in addition to cleaning, the part surface is to be phosphated or activated or if rust must be removed from it, or if the cleaning cycle is preceded by a thermal deburring or nitriding process. As far as the solvents are concerned, a distinction is made between chlorinated hydrocarbons (CHC), non-halogenated hydrocarbons (NH) and modified alcohols alias polar solvents (P). Due to their lipophilic and hydrophilic properties distillable modified alcohols are effective for the removal of non-polar (lipophilic) and polar (hydrophilic) contaminations. They are used as an alternative to hydrocarbons as well as aqueous cleaners.
As process efficiency also depends on the machine engineering, solvents are usually used in fully enclosed automated vacuum parts degreasing/cleaning machines, which are equipped with an integrated distillation unit. In these machines, the solvent can be continuously distilled and regenerated for consecutive cleaning cycles. Thus, they allow for closed-loop use of solvents that enable not only sustainable handling without any contact with the operator, but also a long solvent life. The filtration system and its performance also play a role in the solvent’s life.
This is also true when using an aqueous cleaning system. They are available as machines with one or several work chambers, as continuous-type systems or multi-tank immersion cleaning lines. In a multi-tank immersion cleaning line, the number of treatment baths is virtually unlimited, with the benefit that very high dilution effects are achievable.
Accordingly, fine and ultrafine cleaning are classic application domains of this equipment type. Moreover, multi-tank immersion cleaning lines are advantageous for handling large throughputs since they can treat multiple batches simultaneously.
An approach to make cleaning processes in work chamber machines faster, provide higher throughputs and hence, lower per-unit costs, is reducing idle times. This is made possible by equipping the machines with powerful pumps and large-diameter piping. Energy-optimized pumps and motors, heat recovery systems and stand-by solutions for periods without parts to be cleaned help to decrease the energy consumption of cleaning machines and thus contribute to boost efficiency in parts cleaning. Furthermore, there is a trend toward automation: Any manual operation is not only costly, but also includes some risk of additional contamination.
The employment of alternative cleaning methods such as plasma and carbon dioxide snow jet cleaning is also an option that is used more and more to further optimize cleaning quality and cost effectiveness. However, these techniques are mostly not regarded as a substitute, but instead, as a complement to traditional wet chemical processes.
There are quite a few options to increase efficiency in industrial parts cleaning, and it will be interesting to see how technology will develop further.
The aim is to assess and compare the technical cleanliness of parts produced by different manufacturers or at different locations.
A turbine manufacturing plant phases out an obsolete vapor degreasing system, making the change to aqueous-based cleaning.
Although not every shop has been affected by cleanliness specifications, many suppliers to automotive OEMs are already complying with stringent cleanliness standards. In Ford Motor Co.’s case, it has created its own cleanliness standards in order to save money and credibility.