Alodine, also referred to as iridite, is a chromate conversion coating that is applied only to the surface of aluminum. It gives good corrosion protection as well as providing an excellent base for painting. The process, developed for a major commercial aircraft overhaul facility, involves a cold alodine application followed by a cold water rinse and final hot water rinse.
The above system uses modular MK Series immersion washers for surface treatment. The same alodine process line was also manufactured for another aircraft overhaul facility using the MKT24 Series (below). In this application the customers parts were smaller and the compact MKT had the ideal size/weight ratio. Load and unload roller conveyor sections were added to facilitate staging through the system.
Another Alodine system is shown below. This line also uses the modular Console Series. The line consists of Wash, Heated Rinse, Alodine 5700, Cold Rinse, Heated Rinse and Hot Air Knife Dryer. This is easily and conveniently accommodated in two standard MKD/Q16 Consoles.
A variety of features can be added to the system to enhance the performance of any particular stage. The alodine stage is improved using a turbulation system. The turbo is powered by a high volume all stainless steel pump. Closed looped manifolds with multiple injectors direct the coating solution to the working zone. The system provides an even flow of turbulent solution over, under, around and through components. The flow is adjustable. RAMCO turbo system have been proven to accelerate processing time in most immersion applications. A filtration system is included with the turbo to remove fine particulate. It uses a stainless steel filter canister with a bag element and is equipped with a stainless steel oil filled pressure gauge.
Another enhancement is MultiPort Oscillation. MuliPort can be added to the alodine stage (or any stage) to ensuring solution reaches all surfaces of complex components. MultiPortú permits platform oscillation within different zones of the process chamber. With MultiPort seven strokes are available to choose from, each with a distinct altitude and zone of operation. As an example you can oscillate in and out of solution using a short stroke in just the upper half of the chamber, or switch to an extended long stroke in and out of solution through the entire chamber. This feature lets you fine tune applications for the optimum agitation stroke.
The combination of MultiPort and Turbo/Filter increases overall solution flow to the target working zoning, improves filling and draining of intricate cavities and thereby provides more consistent Alodine coating.
Other options such as Ultrasonics can be used to enhance performance.