Engineering Guide to Selecting the Right Release Liner for PSA Products

No. Different PSA families generally require distinct release liner chemistries:

• Silicone PSAs → Best matched with fluorosilicone liners for stable low release and anti-migration.

• Acrylic PSAs → Typically paired with standard silicone liners. Some specialty acrylics may also show better stability on fluorosilicone liners, but this is formulation-dependent and must be validated.

• Rubber PSAs → Often paired with paper or film liners coated with customized silicone release levels.

Key point: Cross-compatibility does exist but is the exception, not the rule.

Example from validation: One acrylic PSA initially released cleanly from a fluorosilicone liner, but after aging at 70 °C × 7 days, peel force increased by more than 40% with transfer observed. This highlights why adhesive-specific liner selection and accelerated aging tests (per PSTC-4) are mandatory before approval.

PFAS include tens of thousands of substances, and no single test can cover them all. Our compliance approach is to:

• Provide accredited third-party lab reports showing no detection of currently restricted PFAS analytes under EU REACH and US EPA.

• Continuously monitor global regulations, updating testing scope whenever new PFAS are added to restriction lists.

👉 Key message: While PFAS as a family is very large, our products are verified not to contain any PFAS currently restricted by law, ensuring regulatory compliance today and adaptability for tomorrow.

Variability often comes from differences in application, substrate thickness, and test methods.

• For medical and electronics, 75 µm PET is the common baseline; for foam tapes, 100 µm PET is preferred.

• Test results also shift with peel angle, peel speed, dwell time, and even operator technique.

👉 Consultant’s interpretation: In one comparison, the same liner/adhesive system showed 9 g/25 mm in Lab A and 13 g/25 mm in Lab B, simply because the peel angle control differed by ~10°. This is why standardized test protocols (e.g., PSTC-4 at 180° / 300 mm/min / 25 mm width) are critical to ensure comparability.

Curling depends on both liner thickness and application stress:

1. < 50 µm PET

   • High risk of curling during die-cutting or lamination.

   • Often unsuitable for wide web or foam applications.

2. 75 µm PET

   • Balanced option for medical patches and electronics.

   • Provides enough stiffness to resist curling in most flat substrates.

3. 100 µm PET

   • Preferred for foam tapes and thick constructions.

   • Extra rigidity minimizes edge lift and curling under compression.

👉 Consultant’s interpretation: Curling is not only about thickness but also about adhesive shrinkage, coating stress, and storage conditions. For example, one converter saw 50 µm liners curling after 2 weeks at 40 °C storage, while the same PSA on 100 µm PET remained flat. Rule of thumb: thinner liners save cost, but thicker liners (>75 µm) are insurance against curling in high-stress applications.

Adhesive transfer is usually triggered when the release system reaches its stress limit. Common causes include:

• Under-cured release coating → residual siloxane groups interact with PSA under pressure or heat.
• High converting stress → excessive die pressure, nip temperature, or lamination force embedding PSA into the release layer.
• Adhesive migration → low molecular weight components in acrylic or rubber PSAs migrating into the release coating during aging.
• Environmental factors → humidity and static during slitting/die-cutting destabilizing the interface.

👉 Our solution: In medical and electronics applications, we recommend our fluorosilicone liners (e.g., 11-0075 on 75 µm PET). In accelerated aging tests (70 °C × 7 days), these showed <15% change in release force with silicone PSAs, preventing sudden transfer during rotary die-cutting and high-pressure lamination.