Why Does the Release Liner Matter in Foam Tape Production?

When manufacturers focus on foam tapes, most attention is usually given to the foam material and adhesive. However, in actual production, the release liner often determines whether a product runs smoothly through coating, die-cutting, slitting, and final application.

A release liner is more than just a protective layer covering the adhesive. The right liner can improve processing efficiency, reduce production issues, and help maintain consistent product quality. The wrong liner can lead to wrinkling, lifting, unstable release force, and even customer complaints.

For many foam tape manufacturers, silicone-coated kraft release paper remains one of the most practical and widely used liner options.

Why Kraft Release Paper Is Commonly Used for Foam Tapes

Kraft release paper is widely used on EVA foam tapes, PE foam tapes, EPDM sealing foams, neoprene foams, and various die-cut adhesive products.

Compared with glassine release paper, kraft paper offers higher strength and better tear resistance. This becomes particularly important when handling thicker foam materials or larger die-cut parts, where a weak liner can easily break during converting.

Glassine paper still has advantages in precision applications because of its extremely smooth surface and excellent dimensional stability. For electronics, labels, and intricate die-cut components, glassine is often the preferred choice.

However, for many industrial foam tape applications, kraft release paper provides a better balance between performance, handling, and cost.

Kraft Release Paper vs. Glassine Release Paper

In practice, many foam tape manufacturers choose kraft liners because operators find them easier to handle during production and installation.

Why We Recommend Solventless Silicone Coating

Not all release papers perform the same way.

A common mistake is focusing only on the paper weight while overlooking the quality of the silicone coating. In reality, the silicone layer largely determines the release performance.

For foam tape applications, we generally recommend solventless silicone-coated kraft release paper.

The main advantage is consistency.

A well-coated solventless silicone layer helps maintain stable release force across the entire roll, reducing the risk of uneven peeling, liner lifting, or converting problems.

Additional benefits include:

• More consistent release performance
• Better compatibility with acrylic, rubber, and hot melt adhesives
• Lower risk of silicone transfer
• Cleaner production process
• Improved coating uniformity
• Reduced odor compared with some solvent-based systems

Why 75gsm Kraft Release Paper Is Often the Best Choice

Among various specifications available on the market, 75gsm kraft release paper has become one of the most commonly used options for foam tape production.

The structure typically consists of:

• 65gsm kraft base paper
• 10gsm solventless silicone coating

This combination works well because it offers enough strength without becoming unnecessarily heavy.

Manufacturers often prefer this construction because it provides:

Good Strength Without Excessive Cost

The 65gsm kraft paper provides sufficient tensile strength for slitting, rewinding, laminating, and die-cutting operations.

Stable Release Performance

The 10gsm silicone coating creates a uniform release layer that helps maintain consistent release force throughout production.

Better Support for Thick Foam Products

When working with EVA, PE, EPDM, or neoprene foam, a stronger liner helps prevent deformation during converting.

Easier Handling

Operators can grip and remove the liner more easily during assembly and installation compared with very smooth glassine liners.

For many industrial foam tape applications, 75gsm solventless silicone kraft release paper offers a practical balance of performance and cost.

A Common Production Issue: Why Does the Release Liner Wrinkle?

One problem occasionally encountered in foam tape production is liner wrinkling or edge lifting after lamination.

Many people immediately assume the release paper is defective, but the reality is usually more complicated.

Based on production experience, there are four areas that should be checked.

1. Release Paper Quality and Silicone Performance

The release liner itself is often the first place to look.

If the silicone coating is uneven or poorly cured, release force may vary across the roll. Some areas may release too easily while others hold too tightly.

This imbalance can create stress between the adhesive and liner, eventually causing wrinkles or lifting.

For this reason, stable solventless silicone coating is particularly important.

2. Insufficient Initial Adhesive Tack

The release liner stays flat because the adhesive maintains proper contact with it.

If the adhesive's initial tack is too low, the liner may not remain firmly attached to the adhesive surface.

As a result, wrinkles or lifted edges can appear during storage or transportation.

In some cases, the problem is not the release liner at all-it is the adhesive formulation.

3. Adhesive Coating Weight Is Too Low

Another frequently overlooked factor is coating weight.

When too little adhesive is applied, there may not be enough contact area between the adhesive and the release liner.

Even if both the adhesive and liner are technically qualified, insufficient coating weight can still lead to:

• Edge lifting
• Localized wrinkles
• Air pockets
• Poor liner appearance

Checking actual adhesive coat weight often reveals the root cause.

4. Transfer and Lamination Temperature

Temperature during transfer coating and lamination also affects liner stability.

If the temperature is too low, the adhesive may not wet out properly against the release liner surface.

If it is too high, internal stress may develop within the laminate structure.

Either condition can eventually lead to wrinkling after the finished rolls are stored.

Production parameters such as:

• Transfer temperature
• Laminating temperature
• Line speed
• Cooling conditions

should all be reviewed during troubleshooting.

Final Thoughts

In foam tape manufacturing, the release liner should never be treated as a simple accessory.

A high-quality 75gsm solventless silicone-coated kraft release paper not only protects the adhesive but also contributes to stable release performance, efficient die-cutting, and reliable product quality.

When issues such as liner wrinkling occur, it is important to look at the entire production system rather than focusing on a single component. The release liner, silicone coating quality, adhesive performance, coating weight, and processing temperature all work together.

In many cases, solving a liner wrinkling problem starts with asking a simple question:

Is the liner, adhesive, and process actually matched to each other?

That answer often reveals the real cause much faster than replacing materials one by one.