What is Release Force & Why Does it Matter for Your Labels?
Created on 10.24
What is Release Force?
In simple terms, Release Force is the amount of force required to remove a label from its backing paper (also called the liner or release liner).
Think of it like peeling a sticker off a sheet. If it's too hard to peel, you might rip the sticker. If it peels off too easily, it might fall off before you even use it. Release force is the scientific measurement of that "peel-ability."
A label is a three-part system:
1. The Face Stock: The top layer (paper, film, etc.) that you print on.
2. The Adhesive: The sticky layer on the back of the face stock.
3. The Liner (Release Liner): The silicon-coated backing paper that protects the adhesive until use.
The "release" happens at the interface between the adhesive and the silicone coating on the liner.
Why Does Release Force Matter?
Release force is not about making a label "sticky" to the final surface; that's the job of the adhesive. It's about the controlled and reliable application of the label. Getting it right is crucial for both manual and automated processes.
Here’s why it matters so much:
1. For Automated Application (The #1 Reason)
This is where release force is most critical. High-speed label applicators and printers have a "peel plate" that sharply bends the liner, forcing the label to separate and be presented for application.
- Too High (Heavy Release): The label won't release cleanly from the liner. It will "hang up," causing application errors, jams, and costly downtime on the production line. The label can also curl, stretch, or tear.
- Too Low (Light Release): The label will "pop off" or "flag" prematurely. It might fall off the liner inside the printer or applicator, or it will be mispositioned when applied to the product, leading to skewed labels and waste.
- Just Right (Controlled Release): The label releases from the liner predictably and cleanly at the exact right moment, allowing for fast, accurate, and reliable application.
2. For Manual Application & Usability
Even when applied by hand, release force affects the user experience.
- Too High: It's frustrating to peel. The label can tear, curl, or stretch, making it difficult to apply neatly. For small labels (like for circuit boards or pharmaceuticals), it can be nearly impossible to handle.
- Too Low: Labels can fall off the sheet during handling, shipping, or when being fed into a desktop printer. They lose their "liner hold," making them messy and unreliable to work with.
- Just Right: The label is easy to peel by hand without tearing or curling, improving efficiency and reducing operator frustration.
3. For Printability and Die-Cutting
The release force of the liner affects how the entire label stock behaves during the printing and die-cutting process.
- Consistent Release Force: Ensures that labels are die-cut to the correct depth (through the face stock but not through the liner). Inconsistent release can lead to variations in die-cutting, causing some labels to be harder to release than others.
- Matrix Waste (The leftover material around the labels): After die-cutting, the matrix waste is stripped away, leaving the labels on the liner. If the release force is too low, the labels can be pulled off with the waste. If it's too high, the waste won't strip cleanly.
The "Goldilocks Zone" of Release Force
Release force isn't a one-size-fits-all value. It's measured in grams per inch (g/in) or Newtons per 100mm (N/100mm) and falls into general categories:
- Light/Controlled Release (e.g., 10-30 g/in): Ideal for high-speed applications, small labels, and fragile face stocks.
- Medium/Standard Release (e.g., 30-80 g/in): A good all-purpose range for many manual and semi-automated applications.
- Heavy/Tight Release (e.g., 80+ g/in): Used for heavy-duty labels, thick materials, or labels that will be subjected to high heat or pressure before application.
Factors That Affect Release Force
- Silicone Coating: The type and amount of silicone used on the liner.
- Adhesive Chemistry: Some adhesives (especially aggressive permanent acrylics) naturally have a higher release force.
- Face Stock: The weight, stiffness, and rigidity of the face stock influence how easily it peels.
- Environmental Conditions: High temperature and humidity can significantly lower release force, while cold temperatures can make it higher.
- Aging/Dwell Time: The release force can change over time as the adhesive and silicone "settle" together.
How to Ensure You Have the Right Release Force
1. Work with Your Label Supplier: This is the most important step. Reputable suppliers understand release force and can recommend the right label construction (liner/adhesive combination) for your specific application method.
2. Be Specific About Your Process: Tell your supplier if you are using a high-speed applicator, a desktop printer, or applying by hand. Mention the speed of your line if applicable.
3. Request Samples and Test: Before ordering a large quantity, always get samples and test them in your actual environment—on your printer, your applicator, and with your operators.
Summary
Release Force | Impact on Manual Application | Impact on Automated Application |
Too HIGH | Difficult to peel, risk of tearing/curling | Labels jam, don't release, cause downtime |
Too LOW | Labels pop off prematurely, messy to handle | Labels flag and misapply, fall off in machine |
JUST RIGHT | Easy, clean, and predictable peeling | Smooth, reliable, high-speed application |
In a nutshell: Release Force matters because it is the unsung hero of label application efficiency. Choosing the correct release force prevents waste, eliminates machine jams, boosts production speed, and ensures your labels look perfect every time.
Ray
Ferrill
Evelyn