The Best Types of PSA Tapes for Powder Coated Surfaces
Pressure-sensitive adhesive (PSA) tapes are widely known for their versatility and bond strength to most surfaces, which is why they’re used in many applications across multiple industries. That doesn’t mean that any PSA tape can form a strong bond with any surface. Powder coated surfaces are one of those substrates that present unique bonding challenges, requiring specialized solutions that only specific PSA tapes can provide. The very nature of these surfaces makes it uniquely hard to achieve strong adhesion. Why is this, and which tapes form the best bonds with powder coated surfaces?
Find out how you can choose the best tape for this type of substrate.
What are Powder Coated Surfaces?
Powder coating is a finishing process that involves applying a dry powder to a surface and then curing it under significant heat for one or mor hours to create a smooth and durable layer. This method is used to provide a protective and visually pleasing finish to a variety of materials, particularly metals and plastics. The powder can be made from different resins, including polyester, epoxy, and polyurethane, and each material offers different levels of durability, flexibility, and resistance to environmental factors.
You’ll normally find these types of surfaces on:
Vehicle frames, rims, and other automotive components.
Washing machines, refrigerators, and other household appliances.
Garden furniture, playground equipment, fencing, and other outdoor applications.
Industrial machinery parts, tools, and storage units.
Window frames, doors, metal facades, and other architectural features.
The Challenges of Adhering to Powder Coated Surfaces
While these powder coated surfaces are durable, their unique features also make them challenging to form a strong bond. Adhering PSA tapes in applications with powder coated surfaces can be challenging because of several factors:
Low Surface Energy: powder coated surfaces typically have low surface energy (LSE), meaning their attraction to other molecules is low, making it difficult for adhesives to form strong bonds. Materials with less than 36 dynes per centimeter, such as Teflon and polyethylene, are considered LSE materials. Find out more about bonding to LSE substrates here.
Additives: powder coated paint often uses additives to improve durability, enhance gloss, and to improve UV stability. Depending on the additive, these can interfere with the adhesive's ability to bond. This additive may be beneficial for the durability of the coating, for example, but poses a challenge for strong and long-term bonds if the right PSA tapes are not used. Another common additive, polytetrafluoroethylene (PTFE), helps the coating remain hydrophobic.
Hydrophobic Surfaces: the hydrophobic nature of many powder coated surfaces reduce its surface energy, which inhibits surface wet out which allows them repel water and other liquids, including adhesives. This non-wetting property prevents many adhesives from spreading and forming a strong bond (a process known as wetting).
Environmental Factors: temperature sensitivity and exposure to UV light and chemicals can affect the performance of PSA tapes on powder coated surfaces. High temperatures can soften the adhesive, while UV light can cause degradation. While these environmental factors aren’t detrimental to the surface, they can impact PSA tape performance. Since powder coated surfaces are often used in these types of environments, it’s important to select a tape that can match the surface’s environmental resistances.
Temperature Sensitivity: the operating temperatures of applications with powder coated surfaces can vary significantly, from high to low temperatures, impacting the performance of PSA tapes. Moreover, making bonds prior to the powder coating process and subsequent bake cycle will impact the performance of many tapes. Some tapes may lose their adhesive properties or become brittle at extreme temperatures, so select tapes that can operate in the extremely high or low temperatures where your powder coated surfaces are.
Surface Smoothness and Glossiness: powder coated surfaces are very smooth and have a glossy surface, which can reduce the surface bond contact area for the adhesive and make it difficult to achieve a strong bond.
What Do You Need in a PSA Tape for Powder Coated Surfaces?
When selecting a PSA tape for powder coated surfaces, consider the following factors:
Bond Pre or Post Powder Coating: strong initial and long-term adhesion is crucial for ensuring the tape remains in place over time. The first most important question to answer is whether you will be making your bond before or after the powder coat process. Making the bond prior to powder coating means you will likely be bonding to high surface energy metals, which opens up a wide range of PSA options. On the other hand, you will need to choose an adhesive that can withstand the high temperatures seen in ovens during the bake cycle, thereby reducing your PSA options. These bake cycles can often require temperatures of 350°F to 450°F for minutes to hours. At the same time, bonding after powder coating also requires tapes designed for LSE materials, which need to be able to maintain a strong bond on the surface in the operating environment.
Temperature Resistance: tapes must withstand the operational temperatures of the final product, whether high or low. Make sure to choose a PSA tape with a wide operating temperature to ensure a strong bond in any environment. If you know the precise operating temperatures, this will help you select the best tape for the job.
Chemical Resistance: PSA tapes should be durable against any solvents, oils, or other chemicals they may encounter during use. Your powder coated surface may be able to repel the chemicals, but the tape you choose may not. Make sure to look for the applicable resistances your PSA tape needs, even if it’s only moisture resistance.
Thickness and Conformability: consider the contours and textures of the powder coated surface. More textured paint surfaces may require a thicker layer of adhesive or a thicker tape to fully wet out the peaks and valleys of the paint surface. More Conformable tapes may be required to ensure consistent contact and adhesion depending upon the complexity and contours of the shape of your surface.
UV Resistance: for outdoor applications, consider potential degradation from sunlight and UV exposure. UV-resistant tapes maintain their properties even after prolonged exposure to the sun.
The Best Types of PSA Tapes for Pre-Powder Coat Bake Cycle
Acrylic-Based PSA Tapes
Most acrylic PSA tapes bond very well to high surface energy (HSE) materials like steel and aluminum. They also have a wide range of operating temperatures and chemical resistances, making them suitable for many different types of environments. However, only some acrylic PSA tapes can withstand the severe conditions of a powder coating oven for hours.
Some acrylic PSA tape options for bonding before the powder coat bake cycle include:
Silicone Based PSA Tapes
Silicone PSA tapes provide exceptional temperature and chemical resistance, allowing them to be used in extreme conditions and very high temperatures. Many of these types of tape adhere well to powder coated surfaces and are often used in high-temperature masking, splicing, industrial assembly, and anywhere performance in harsh conditions is essential.
Some silicone PSA tape options for bonding before the powder coat bake cycle include:
The Best Types of PSA Tapes for Powder Coated Surfaces
Acrylic-Based PSA Tapes
Acrylic PSA tapes can be modified to bond well to most materials, including LSE substrates and powder coated surfaces. They also have a wide range of operating temperatures and chemical resistances, making them suitable for many different types of environments. These types of tapes are often used in automotive trims, appliances, and many other applications. Their strong adhesion to low surface energy materials makes them a durable and very reliable option.
Some acrylic PSA tape options for powder coated surfaces include:
Rubber Based PSA Tapes
Rubber PSA tapes are most known for their high initial tack and strong immediate bond. They are suitable for temporary and indoor applications where ease of use is prioritized, but they are not known to perform well in outdoor applications or those with high temperature extremes. They are often used in indoor furniture, appliances, and HVAC systems.
Some rubber PSA tape options for powder coated surfaces include: