One of the more frustrating aspects of being a paint applicator is having to deal with the buildup of paint on your racks and fixtures. These custom components are a considerable investment for many applicators and ensuring that they remain functional and lasting is critical to managing a process’s operation cost. Several different methods are used to maintain these components including burn-off ovens, fluidized sand beds, & chemical paint stripping; each with its own advantages and disadvantages.
For paint stripping, several factors are considered to determine the most appropriate product to use. Considering that racking components are often made from ferrous materials; alkaline or caustic solutions are a great option to consider. These products are a workhorse in efficiently removing a variety of different paints and are becoming more prevalent in the coating industry. Compared to other chemical solutions, these products are among the most cost-competitive – making them easy to scale in either an inline or offline process.
Caustic paint stripping products utilize an aqueous hydroxide solution as the primary builder; this component facilitates the depolymerization of the paint molecules, causing the paint to degrade. Additionally, other organic components are also used in these products to help swell and lift the paint from the substrate as it is being broken down. Typically, these two portions of the product (aqueous and organic) aren’t homogenous, especially after first use. Because of this, you’ll often find that these products are offered either pre-blended or as a two-component system, depending on what makes the most sense for the application. Since these chemistries are biphasic, there is a greater amount of control over the process. Independent controls allow you to fine-tune these products to the optimal level for your specific needs – balancing your operational efficiency & allowing you to control your chemical use cost.
Other factors that will influence the effectiveness of paint stripping include temperature, agitation, and filtration. Increasing the operating temperature of any paint stripper is going to increase its performance; the organic ingredients in caustic strippers possess high boiling points, so these products can readily be heated up to 200°F. Agitation not only ensures that the two phases remain thoroughly mixed while processing, but also creates turbulence and impingement on the parts – increasing the rate at which the paint is broken down and removed. Lastly, filtration is another important aspect of these processes. Ensuring that the paint removed from the racks is subsequently removed from the bath is the best way to prolong the life of the solution and keep it functioning properly.
Contributed by: Connor Callais