Reflective Tape Longevity: Factors and Considerations
When reflective tape is applied to a surface, its longevity depends on various factors. Before discussing these, let’s define “lifespan.” In this article, “lifespan” refers to the number of months or years that a reflective product performs at an acceptable degree. To achieve this, reflective tape must stay on, remain intact, and provide retroreflectivity at an acceptable level. Once reflective tape falls below a certain light return threshold, its lifespan is considered over. For tapes like sign sheeting or DOT C2 tape for trucks, minimum acceptable levels of reflectivity are set by regulation, making it easier to establish the end of life for these tapes. Generally, reflective tapes should be replaced when they have lost 30% of their original reflectivity, and at a 50% loss, they are considered to be at the end of their useful life.
It’s important to note that outdoor life should not be confused with shelf life, which will be covered in another article. The lifespan discussed in this article is from the time the tape is put into service to the time it no longer functions adequately.
Material Composition and Types – Factory Longevity Estimate in Typical Conditions
Virtually all manufacturers assign an outdoor life expectancy for their reflective tapes. Generally, this is the amount of time a particular tape will reflect at levels sufficient to maintain its Type category. For example, a Type 1 tape is expected to maintain Type 1 reflectivity requirements as well as chromaticity levels for about 5-7 years. Brighter tapes that far exceed the minimum requirements for their type are normally given a longer outdoor rating, ranging from 7 to 12 years. Here are a few examples to give you an idea of how long you can expect any particular reflective tape to perform:
- Engineer Grade Reflective Tape (Type 1)
- Material Composition: Typically constructed from glass beads embedded within a polymer film. Known for affordability and good reflectivity.
- Lifespan: Approximately 5 to 7 years.
- Usage Scenarios: Commonly used for non-critical applications such as temporary traffic signs, vehicle graphics, utility posts, and general safety marking.
- High-Intensity Prismatic Tape (Type 4)
- Material Composition: Incorporates prismatic lenses embedded in a durable polymer film and backed with an air space (air backed prismatic). Reflects light more efficiently for higher visibility.
- Lifespan: Around 7 to 10 years.
- Usage Scenarios: Suitable for permanent traffic signs, construction vehicles, and other high-visibility needs.
- Metalized Prismatic Reflective Tape (Type 5 or equivalent)
- Material Composition: Utilizes highly efficient prismatic lenses coated with a metalized mirror finish, returning light at incredible intensities and narrow angles.
- Lifespan: Typically around 8-10 years.
- Usage Scenarios: Used for traffic delineators, chevrons on emergency vehicles, marine applications (SOLAS), bollards, etc.
- Diamond Grade and DG3 Reflective Tape (Type 8 and Type 11)
- Material Composition: Utilizes ultra efficient or full-cube prismatic lenses backed by a layer of air space, enhancing reflectivity significantly. Often referred to as air-backed prismatic films.
- Lifespan: Typically around 10-12 years.
- Usage Scenarios: Used for emergency vehicles, heavy-duty road signs, and high-risk areas requiring maximum visibility.
Environmental, Application Surface, and Work Environments That Reflective Tapes Must Endure
Environmental Exposure
Factory lifespan estimates take into consideration the following environmental factors. However, if any of these elements are above normal levels, the factory estimate will be diminished, often significantly.
- UV Radiation: Continuous exposure to sunlight can degrade the polymer film, reducing reflectivity over time. UV-stabilized tapes are recommended for outdoor usage in sunny climates.
- Temperature Extremes: Fluctuations in temperature can cause the tape materials to expand and contract, potentially weakening adhesion and causing cracks or peeling.
- Moisture and Humidity: Continuous exposure to moisture, rain, or dew can impact the adhesive and reflective layer. High-quality, weather-resistant tapes are designed to withstand these conditions.
Application Surfaces
Proper application to a sound surface is critical. Less than optimal surfaces or incorrect applications can reduce a tape’s outdoor life.
- Surface Preparation: The longevity of the tape greatly depends on the surface it is applied to. Clean, dry, and smooth surfaces ensure better adhesion. Contaminants such as oil, grease, or dirt can shorten the tape’s lifespan.
- Surface Material: Different materials like metals, plastics, and painted surfaces may impact the adhesion quality. Specific tapes are formulated for optimal performance on various substrates.
- Sealing the Backing: Tapes are most vulnerable at the point where they contact the surface. It is important that the backing of the tape be sealed completely to the surface it is applied to. If weather, dirt, grime, or water are able to get behind the tape, the outdoor life can be substantially decreased.
Work or Service Environment
The environment in which a reflective tape is placed has a marked effect on the life of the tape. Salt air, continuous impacts, blowing sand, regular pressure washing, and other factors can degrade a tape over time. Tape in these kinds of environments should be replaced when a decrease in reflectivity is noticed. If tape is coming apart or cloudy, it should be replaced.
- Impacts: Areas with frequent mechanical contact or abrasion can see faster wear. Opting for tapes with high abrasion resistance will enhance longevity. DOT C2 tape on trucks is an excellent example of this. Tapes that are impacted in their line of service can begin to come apart. This normally takes place over a long period of time; however, in certain work environments, this process can be accelerated.
- Pressure Washing: High-pressure washing with harsh detergents can lower the life of a film, especially if the pressure degrades the seal between the backing of the tape and the surface.
Maintenance and Durability
Maintenance Practices
- Regular Cleaning: Keeping the tape free from dirt, grime, and other obstructions can maintain its reflective efficiency. A simple wipe-down with a mild detergent and water can suffice. This removes dirt and grime that can etch the surface over time.
- Inspection: Periodic checks for any signs of wear, peeling, or discoloration help address issues before they compromise safety and visibility.
Resistance to Physical Wear
- Abrasion: Areas with frequent mechanical contact or abrasion can see faster wear. Opting for tapes with high abrasion resistance will enhance longevity.
- Impact: High-impact areas require tapes with added tensile strength to resist tearing and damage.
Extending the Outdoor Life of Reflective Tape
One simple way to extend the life of any reflective tape is to use a crystal clear laminate to protect it. This extends the life of the tape in two ways.
- UV Protection: Applying a crystal clear UV resistant cast laminate of another film protects it from UV rays. Since the suns rays damage reflective films over time, this application can greatly increase the life of the tape.
- Abrasion Protection: Good quality case laminate is crystal clear tough. It adds a layer of protection against abrasion which keeps the tape in better condition over time.
- Protection from Delamination and Lifting: A clear laminate prevents tape from lifting by sealing the edges to the substrate. It also holds the edges of the tape together so that even with impacts, the tape stays intact and functioning.
Compliance and Outdoor Ratings
Manufacturer’s Outdoor Expected Life
- 5 to 7 Years: Typical for engineer-grade tapes, indicating reliable performance under normal conditions.
- 7 to 12 Years: For high-intensity prismatic and diamond-grade tapes, reflecting their capability to maintain high visibility for longer periods.
- NOTE: These times can be either extended or reduced depending on the environment, maintenance, and additional protection. For critical applications like DOT C2 reflective tape for trucks, periodic replacement of all the tape a few years before the expected end of its lifespan is a prudent measure to protect other drivers and reduce the risk of excess liability in the event of an accident. Lamination is not recommended for these tapes; instead, replacement is advised. You do not want to have an accident and then realize that the DOT tape on your truck was sub-standard.
Quality Standards
- Compliance with Standards: Tapes meeting standards such as ASTM D4956 (American Society for Testing and Materials) provide assurance of quality and longevity.
For a dive into the specifics of each tape type, including technical details, I recommend consulting the technical data sheets available at the following link: Technical Specifications.
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