Mastering Metal Cleaning: Top Considerations for Effective and Safe Solutions
Sea-Land Chemical Company |
Metal cleaning is essential across various industries, ensuring that components are free of contaminants, rust, and residues that could affect performance or longevity. With numerous cleaning methods available, each offering unique benefits and drawbacks, selecting the right approach can be challenging. Whether you’re looking to enhance efficiency, reduce costs, or prioritize environmental and safety concerns, understanding the nuances of these cleaning methods is key to optimizing your processes.
5 Considerations for Developing a Metal Cleaner
By considering the specific alloys, soil types, part geometry, efficiency, and cleaning fluid type, you can develop a metal cleaner that meets your performance needs while balancing cost, safety, and environmental impact.
1. What Alloys Are Being Cleaned?
Different alloys, like stainless steel or aluminum, react differently to cleaners. It’s crucial to choose a cleaner that won’t damage the specific metal; consider factors like corrosion or tarnishing.
2. What Types of Soils Are Being Removed?
Identify the contaminants—such as oils, coolants, or particulate matter. The cleaner must be effective against these specific soils to ensure thorough cleaning without leaving residues.
3. Geometry of the Parts Being Cleaned
Parts with complex shapes or internal cavities require cleaners that can effectively reach and clean these areas. Specialized application methods or cleaners with good wetting properties are often necessary.
4. Efficiency of Cleaning Process
The cleaner should work efficiently, minimizing time, energy, and operational costs by operating at lower temperatures and shorter cycles. It should also generate minimal waste to reduce disposal costs and meet environmental standards. Additionally, a long-lasting cleaner that’s gentle on equipment reduces the need for frequent maintenance and fluid replacement.
5. Cleaning Fluid Types
Solvent-based cleaners are strong against oils and grease, offering quick drying times. However, they may pose environmental and safety risks, such as VOC emissions. Aqueous cleaners are safer and more environmentally friendly, ideal for removing water-soluble soils. However, they may require longer drying times and more energy for heating.
Solvent Based Metal Cleaning Fluids
Traditional solvents are used as the base of these cleaners. Common solvents used include trichloroethylene (TCE), perchloroethylene (PERC), and N-Propyl Bromide (NPB). The benefits of working with a solvent-based cleaner include
- Excellent affinity for hydrocarbons, non-polar soils
- Fewer steps
- Lower surface tension & viscosity for better wetting
- Less waste is generated
- Easier to reuse/recycle
However, solvent-based cleaners also offer a wide range of disadvantages:
- Growing regulatory restrictions, select states have banned TCE
- VOC’s
- Environmental, health, safety and air quality concerns
- EPA has published risk assessments for halogenated solvents
The EPA continues to assess health and environmental risks associated with these products. This has led to the growing favorability of aqueous-based metal cleaners. Chemists continue to access these formulations and how they can do the same cleaning.
Aqueous Metal Cleaners
Cleaning with an aqueous cleaning requires different steps and equipment. A solvent-based cleaner will evaporate, while its counterpart, aqueous cleaning, requires the use of cleaning, rinsing, and drying steps. Additionally, aqueous metal cleaners require heat, agitation, time, and specialty formulations to boost performance. The components of an aqueous metal cleaning formulation are;
- Builders: increase alkalinity, buffer
- Chelants: water quality & solubilize soils
- Surfactants: emulsification, detergency, wetting
- Hydrotropes: solubilize soils
- Corrosion Inhibitor: rust & stain protection
When selecting these additives, special consideration is needed to clean each application and part.
Advantages and Disadvantages of Aqueous Cleaners
Aqueous cleaners, which begin with a water base, present several key advantages that make them a compelling choice for metal cleaning applications. First and foremost, the water-based composition offers a significant cost advantage over solvent-based alternatives. Water is not only more affordable but also more readily available, reducing the overall expense of the cleaning process. This cost efficiency makes aqueous cleaners an attractive option for industries seeking to manage expenses without compromising cleaning effectiveness.
Perhaps the most substantial benefit of aqueous cleaners lies in their improved safety and environmental profiles. Unlike many solvent-based cleaners, which can be hazardous to both human health and the environment, aqueous cleaners are generally less toxic and pose fewer risks. They typically produce fewer volatile organic compounds (VOCs), which contribute to air pollution and are harmful to workers’ health. This reduction in hazardous emissions makes aqueous cleaners a more sustainable choice, aligning with growing regulatory demands and corporate responsibility initiatives focused on environmental stewardship.
Furthermore, aqueous cleaners offer greater flexibility in formulation. Manufacturers can tailor these products to meet specific performance requirements, allowing for customization based on the particular needs of different applications. Aqueous cleaners can be engineered to achieve the desired results, whether it’s enhancing cleaning power, ensuring compatibility with certain metals, or adjusting for specific temperature conditions. This adaptability ensures that industries can rely on aqueous cleaners for various metal cleaning tasks, from general maintenance to highly specialized operations.
Several disadvantages must be considered when considering the use of aqueous metal cleaners. Corrosion can be a significant issue, particularly with ferrous and copper alloys, which often require additional post-inhibition treatments to prevent damage. Additionally, the wastewater generated during the cleaning process will require treatment. The cleaning process often requires 2 to 5 separate steps in different compartments, including cleaning, rinsing, and drying. Different cleaning formulations will be needed for different metals to ensure compatibility.
Moreover, aqueous cleaners tend to require more intricate formulations to be effective. Compared to solvent-based cleaners, aqueous cleaners also demand more energy, particularly for maintaining the necessary heat during cleaning and drying phases. This higher energy requirement often results in longer wash cycles, making the process less efficient overall.
Common Part Cleaning Methods
Spray Cleaning
A detergent or solvent-based cleaner is sprayed onto the surface. Effectiveness depends on nozzle shape, angle, and pressure, making it suitable for easily accessible surfaces.
Immersion Cleaning
Parts are fully submerged in a cleaning fluid, either aqueous or solvent-based. Heat (for aqueous solutions) and soaking time enhance performance. Rinsing and drying occur in separate tanks, ideal for parts with complex geometries.
Ultrasonic Cleaning
Uses ultrasound vibrations to create cavitation bubbles in the cleaning fluid. These bubbles burst, releasing energy that scrubs away contaminants, perfect for deep cleaning parts with intricate shapes.
In summary, developing an effective metal cleaner requires careful consideration of several key factors, from the types of alloys and soils involved to the geometry of the parts and the efficiency of the cleaning process. By understanding the unique challenges posed by each component and selecting the appropriate cleaning fluid—whether solvent-based or aqueous—you can optimize the cleaning process for both performance and cost-effectiveness. The right combination of these elements ensures that your metal parts are thoroughly cleaned, protected, and ready for their intended application, ultimately enhancing the quality and longevity of your products.
