Sustainability has become a crucial consideration in virtually all sectors of industry, driving the development of new technologies and manufacturing methods. The core principles of sustainability—commitment to long-term improvements in economic, environmental, and social benefits—have profoundly influenced corporate and cultural perspectives on products. However, the concept of "green" has often been accepted as synonymous with sustainability. This has led to a misunderstanding that sustainable products are associated with higher costs. True sustainability extends beyond this notion and does not necessarily entail increased expenses. In the context of pretreatment and painting processes, significant advancements have been made towards sustainability. This discussion will explore how Chemetall has applied the essential concept of sustainability to manual wand pretreatment, an industry-standard practice.
Manual Wand Use with Traditional Zinc and Iron Phosphating
The manual wand pretreatment process is a method for cleaning and preparing metal surfaces prior to painting or coating. This involves the use of a handheld or mechanical spray wand that applies pretreatment chemicals, traditionally including cleaners, phosphates, and sealers, to remove contaminants, enhance paint adhesion, and improve corrosion resistance.
The standard phosphate process begins with applying a heated cleaner to eliminate oils, dirt, and other impurities from the metal surface, followed by rinsing to wash away the cleaner and any residue. A heated phosphate pretreatment chemical is then applied at relatively high pressure through the spray wand, creating a protective layer that enhances paint adhesion and corrosion resistance. Often the cleaning and phosphating steps can be combined into a cleaner-coater program that does not require the intermediate rinse step. Finally, the surface is rinsed again to remove any excess pretreatment chemicals. A sealer may or may not follow the rinse to provide additional adhesion and corrosion protection.
Chemetall has provided phosphate pretreatments for manual wand processes for many years. This manual process is typically used for large parts unsuitable for automated lines which require extremely large spray or immersion booths. Despite its effectiveness and long-standing use, phosphate manual pretreatment presents several challenges:
• Inconsistent Application: Manual application can result in variability in the amount of pretreatment chemical applied, leading to inconsistent coating quality and performance.
• Accessibility Issues: Complex parts or extremely large parts can be difficult to reach with appropriate temperature, pressure, and time for the iron phosphate coating to form.
• Environmental Concerns: The use of phosphates must comply with environmental and discharge regulations, which can limit the use or volume of pretreatment chemicals.
• Energy Intensive: The process requires significant energy to heat the cleaners and phosphate coatings continuously.
• Flash Rust: Parts that sit for extended periods before painting can develop flash rust, affecting the final coating's quality.
• Safety: The use of high temperature, high pressure, acidic materials require special handling and PPE.
Manual Wand Use with Thin Film Pretreatments
Chemetall was the first company to introduce a multi-metal thin-film technology to the market — long before most of the current developments
had taken place. Now, Oxsilan® and Gardobond® represent mature alternatives—comparable in terms of quality to phosphating. With a view to their technical and economic profile, these thin film technologies clearly show advancements in terms of higher productivity and multi-metal capability, resulting in considerably lower process costs. These globally recognized, pioneering thin-film pretreatment technologies are used across multiple industries, such as Aluminum Finishing, Appliances, Automotive OEM and Components, Coil, General Industry Manufacturing, and ACE (Agriculture, Construction, Earthmoving).
The baseline advancement in sustainability with thin film pretreatments is that thin films can achieve the same degree of corrosion protection as 5-10X times thicker phosphate coating weights, reducing material consumption and pretreatment times even before selecting the method of application. Improvements in efficiency up to 65% have been realized in practical applications.
The development of thin film pretreatment manual wand programs has provided the opportunity to increase the sustainability of the industry’s manual wand processes. Chemetall has developed programs utilizing thin film pretreatment technology to achieve higher quality while enhancing overall process sustainability.
Thin film pretreatment processes offer numerous advantages over traditional iron phosphate manual pretreatment programs. These thin film processes are designed to be more energy-efficient, environmentally friendly, and cost-effective.
One of the primary benefits of lower temperature pretreatment processes is the significant reduction in energy consumption. Traditional iron phosphate treatments typically require high temperatures, often exceeding 120°F, to be effective, leading to substantial energy costs. Conversely, thin film pretreatment processes operate at much lower temperatures, typically ambient, reducing the energy needed to heat the pretreatment tank. This lowers operational costs and decreases the pretreatment process's environmental carbon footprint.
Lower temperature systems can also extend equipment life and reduce maintenance costs. High-temperature systems can strain equipment, leading to increased part replacement costs and downtime.
Thin Film pretreatment conversion coatings do not require heat or high pressure, needing only ample contact with the substrate. This eliminates the need for high-pressure applications required in iron phosphate pretreatments.
Another significant advantage of thin film pretreatment processes is their reduced environmental impact. Traditional iron phosphate treatments use phosphates, which can harm the environment and also lead to iron solid waste that requires regular removal and disposal. Thin film pretreatment processes, such as zirconium-based treatments, eliminate the need for phosphates, reducing environmental impact and minimizing precipitate production. This makes the process more environmentally friendly and reduces labor and treatment/disposal costs.
Water conservation is another benefit of thin film pretreatment processes. Traditional iron phosphate treatments require significant water volumes under pressure to create the coating. Thin film pretreatments do not require high pressure, reducing water usage and waste flow. This is particularly important in regions with limited water resources, high treatment costs, or heavy regulation on water usage.
Furthermore, thin film pretreatment processes can improve coating quality by providing better adhesion and corrosion resistance than iron phosphate treatments. This results in a more durable and long-lasting corrosion resistant layer, beneficial in industries where the pretreatment-paint longevity is critical, such as automotive, heavy industry, and aerospace.
In summary, lower temperature, lower pressure, thin film pretreatment processes offer significant economic, environmental, and quality advantages over traditional iron phosphate manual pretreatment methods. These processes support sustainability by reducing energy and water consumption, minimizing harmful chemical use, and improving the environmental performance of industrial paint operations. They represent a superior choice for industries committed to sustainable practices and environmental stewardship. Contrary to the misconception that sustainable products are more costly than traditional technology, advancements in thin film pretreatment manual wand pretreatments demonstrate otherwise.
For more information on these technologies or this topic, please contact Chemetall.