Episode 2 – Ask the Technical Expert: Application Temperature vs. Service Temperature: What’s the Difference?
Here’s a scenario I’ve seen many times.
A customer needs a label that will withstand freezing temperatures.
They select a label material whose specifications say it can perform at those temperatures.
The product is labeled.
And the labels start falling off.
The reaction is understandable:
“But the specification says this label is rated for cold temperatures.”
It probably is.
The question is when it encounters those temperatures.
That’s the difference between two specifications every label buyer should understand: application temperature and service temperature.
They sound similar.
They aren’t.
What Is Application Temperature?
Application temperature refers to the temperature of the environment and, importantly, the substrate when the pressure-sensitive label is initially applied.
This is the point at which the adhesive needs to make contact with the surface and begin developing its bond.
If the surface is too cold for a particular adhesive, the adhesive may not flow and wet out across the surface sufficiently to develop the intended bond.
That’s why simply checking the temperature of the room isn’t always enough.
If a product just came out of a refrigerator or freezer, the container itself may be much colder than the surrounding environment.
That’s the temperature I’m interested in.
What Is Service Temperature?
Service temperature describes the temperature range the label construction can withstand after it has been properly applied and the adhesive has had an opportunity to build its bond.
That range can often be considerably broader than the allowable application temperature.
This leads to one of the most important lessons I teach customers about cold-temperature labeling:
That distinction can completely change the material you select.
Surviving the Cold Isn’t the Same as Bonding in the Cold
Think of adhesion as a process rather than an instantaneous event.
When you press a pressure-sensitive label onto a surface, you want the adhesive to establish intimate contact with that substrate.
Then the bond develops.
Only after that do we ask the second question:
What does the label need to survive?
Maybe the product goes into a refrigerator.
Maybe it’s frozen.
Maybe it moves between warm and cold environments repeatedly.
Maybe it encounters water, ice or condensation.
Those conditions matter, but they’re not necessarily the conditions under which the original bond should be created.
Pressure-sensitive adhesive manufacturers distinguish between application and service conditions for exactly this reason.
The Problem Gets Even More Interesting With Condensation
Cold temperatures often introduce another variable: moisture.
Take a cold container into a warmer environment and condensation can begin forming on the surface.
Now you’re not simply trying to bond an adhesive to glass or plastic.
You’re trying to bond through a layer of moisture.
That can dramatically change what construction is appropriate.
It’s why telling your label supplier, “This needs to go in a refrigerator” isn’t enough information.
I want to know:
Is it cold when we’re labeling it?
Is it wet when we’re labeling it?
Those are different technical challenges.
A Real Application Has a Temperature Journey
Instead of thinking about one temperature, I encourage customers to think about the temperature journey of the product.
For example:
Before labeling:
Where has the product been stored?
During labeling:
What is the actual surface temperature of the container?
Immediately afterward:
Where does the product go next?
During distribution:
Is it refrigerated, frozen or exposed to outdoor temperatures?
During use:
Will consumers or employees repeatedly move it between different environments?
That gives us a much better understanding of what the label construction actually needs to accomplish.
Why Dwell Time Matters Too
There’s another piece of the puzzle that’s easy to overlook.
Adhesives generally need time to develop their bond.
Avery Dennison notes that pressure-sensitive adhesives take time to reach optimum strength, while its technical application guidance also emphasizes maintaining appropriate application conditions long enough for adhesion to build.
That means a process where a label is applied and immediately moved into a harsh environment can behave differently from one where the adhesive has more opportunity to build its bond first.
Again, we’re looking at the entire process rather than just one specification on a data sheet.
Questions to Ask Before Choosing a Cold-Temperature Label
Before selecting a material, I recommend answering these questions:
- What is the temperature of the actual surface when the label is applied?
- Is the surface wet or dry?
- Is condensation possible?
- What is the lowest temperature the label will encounter after application?
- How soon after application will the product enter refrigeration or freezing?
- How long does the label need to remain functional?
- Is the substrate glass, plastic, corrugated or another material?
- Will the product move repeatedly between temperature environments?
Once we understand those variables, choosing the right construction becomes much easier.
Don’t Design for the Destination Alone
Here’s the key takeaway: Don’t select a label based only on where the product ends up.
Understand how it gets there.
A label may ultimately need to withstand a freezer, refrigerated warehouse or outdoor winter environment. But how and where that label is originally applied can be just as important as the final service conditions.
The best labeling solutions account for both.
At ID Images, that’s why we encourage customers with challenging temperature applications to bring our technical team into the project early.
Sometimes the solution is a specialty cold-temperature adhesive.
Sometimes it’s a change in the application process.
Sometimes the most important discovery is a variable nobody had thought to ask about.
Finding that out before production is considerably easier than troubleshooting thousands of labels afterward.
Quick Answer: What’s the Difference Between Application and Service Temperature?
Application temperature is the temperature at which a label is initially applied and begins forming its adhesive bond. Service temperature is the range of temperatures the label can withstand after application and after sufficient bond development. A label can therefore withstand temperatures in service that may be unsuitable for initial application.
Planning a refrigerated, frozen or temperature-sensitive labeling application? Talk to ID Images before selecting your material so we can evaluate the complete application.
By John Signet, Technical Solutions Manager, ID Images and Chair, TLMI Technical Committee