When specifying a plastisol dip coating, one of the most important considerations is coating thickness. The amount of plastisol applied to a component can influence everything from how the finished part feels in the hand to how well it withstands impact, abrasion, and everyday use.
There is no single “ideal” coating thickness for every application. Instead, the right thickness depends on the component, its intended use, and the performance characteristics required from the finished product.
At Piper Plastics, controlling these variables is an important part of developing a successful dip coating process.
Why Does Coating Thickness Matter?
Plastisol dip coating can serve many different purposes. On one component, the coating may primarily provide a comfortable gripping surface. On another, it may protect the underlying metal or prevent the component from damaging surfaces it contacts.
The thickness of that coating plays a significant role in determining how it performs.
A relatively thin coating can provide a clean, protective layer while maintaining the shape and dimensions of the original component. A heavier coating can provide additional cushioning, impact protection, insulation, or a more substantial grip.
The goal isn’t necessarily to apply the thickest coating possible. It’s to apply the appropriate amount of plastisol for the application.
How Thickness Changes the Finished Part
Increasing or decreasing coating thickness can change several characteristics of a dip-coated component.
Grip and Comfort
For handles, levers, and other components that are regularly handled by the user, coating thickness can affect both comfort and grip.
A thicker layer of plastisol can create a softer, more substantial gripping surface and provide additional cushioning between the user’s hand and the underlying metal.
However, the ideal thickness depends on the product. A component requiring precise handling may benefit from a different coating profile than a heavy-duty industrial handle.
Impact and Surface Protection
Plastisol can also act as a protective barrier between a metal component and its surroundings.
A thicker coating can provide additional cushioning when parts are bumped, dropped, or brought into contact with other surfaces. This can be particularly useful when the underlying metal could otherwise scratch or damage another component.
The plastisol itself also helps protect the coated substrate from normal wear and environmental exposure.
Electrical Insulation
For certain applications, plastisol can provide electrical insulating properties.
In these cases, coating thickness may be one of several factors considered when developing the coating specification. The plastisol formulation, substrate, operating environment, and other application requirements must also be taken into account.
Appearance and Finished Dimensions
Thickness doesn’t only affect performance. It also changes the appearance and dimensions of the finished component.
A heavier coating can soften sharp contours and create a more rounded appearance, while a thinner coating may preserve more of the original geometry of the part.
This is particularly important when a coated component must fit alongside, inside, or through another part. Engineers need to account for the additional dimensions created by the coating when designing the finished assembly.
What Determines Plastisol Coating Thickness?
During dip coating, thickness isn’t determined by a single setting.
Several manufacturing variables work together to influence how much plastisol builds up on the component. These can include the temperature of the part, the plastisol formulation, the amount of time the component remains immersed, withdrawal conditions, and the geometry of the part itself.
Because these variables interact with one another, establishing the correct process is an important part of producing a consistent coating.
For example, two components dipped into the same plastisol may not necessarily develop identical coatings if their size, shape, material, or thermal characteristics are different.
Part Geometry Matters
The shape of the component can have a significant effect on the finished coating.
Corners, edges, recesses, changes in diameter, and other geometric features can influence how plastisol flows and builds around a part. This is one reason why dip coating specifications need to consider the actual component, rather than coating thickness as an isolated number.
For custom applications, evaluating the geometry of the part alongside the desired coating characteristics can help determine the best manufacturing approach.
Consistency Is Just as Important as Thickness
Specifying the right coating thickness is only part of the challenge. Manufacturers also need to be able to reproduce that coating consistently from one production run to the next.
Variables such as temperature, timing, dipping speed, and withdrawal speed need to be carefully controlled to produce repeatable results.
At Piper Plastics, we use custom-engineered, computer-controlled dipping equipment to manage critical process parameters during production. This level of process control helps us produce consistent results while adapting the dip coating process to the requirements of each application.
Finding the Right Coating for Your Application
When developing a dip-coated component, it’s helpful to think about what the coating actually needs to accomplish.
Does the product need a comfortable grip? Additional cushioning? Protection from impact or abrasion? Electrical insulation? A particular finished dimension or appearance?
The answers to those questions help determine the appropriate coating characteristics—and ultimately the manufacturing process required to achieve them.
Rather than treating plastisol coating thickness as a one-size-fits-all specification, Piper Plastics works with customers to develop a dip coating process around the needs of the finished component.
Have a part that requires plastisol dip coating? Contact Piper Plastics to discuss your application, coating requirements, and production needs.