Why Dual Co-Extrusion Casting Eliminates Delamination in TPU Color-Change Film

Created on 10.22

If you've been in the wrap business long enough, you've seen it: a color-change film that looked perfect at installation starts to bubble or peel at the edges two or three years later. In most cases, the culprit isn't the installer or the environment—it's the adhesive layer.

Most TPU color-change films on the market are built using a two-layer lamination process. Two TPU layers are produced separately, then bonded together with an adhesive. This adhesive layer is the film's structural weak point. Over time, exposure to moisture, heat, and UV causes the adhesive to age and hydrolyze—a chemical breakdown triggered by water absorption. Once the adhesive degrades, the layers begin to separate, producing the delamination and bubbling that end users complain about.

Our TPU color-change film is manufactured using a dual co-extrusion casting process. The two TPU layers are formed in one piece while in a molten state, rather than being made separately and laminated afterward.

The difference is fundamental:

No adhesive layer.

 Because the layers are fused during extrusion, there is no adhesive to age, hydrolyze, or fail.

Molecular-level bonding.

 The two TPU layers are joined at the molecular level, creating a single continuous structure rather than two sheets held together by glue.

Elimination of delamination risk.

 With no adhesive interface, the primary cause of delamination—adhesive aging and hydrolysis—is fundamentally removed.

The practical benefits show up over the life of the installation:

Greater structural stability.

 The film behaves as one material, not two bonded layers, so it holds its shape and integrity under thermal cycling and mechanical stress.

Superior hydrolysis resistance.

 Without an adhesive layer to absorb moisture and break down, the film resists the hydrolytic degradation that plagues laminated films in humid climates.

Far lower risk of delamination and bubbling.

 Long-term performance is significantly more predictable—critical for installers offering multi-year warranties and for distributors protecting their brand reputation.

For distributors and installers, this translates directly into fewer warranty claims, fewer rework jobs, and a product you can stand behind.

This co-extrusion capability is part of TopsayPPF's broader manufacturing platform. We produce 100+ color options across PPF, window film, color wrap, and PDLC using premium TPU materials, with a monthly capacity of 200,000 m². Our films are certified to ISO 9001, IATF 16949, SGS, REACH, and RoHS, and backed by a 10-year warranty with professional installation guidance.

With warehouses in California, Rotterdam, Dubai, and Shanghai, we deliver to distributors in 70+ countries—combining advanced material engineering with the supply reliability your business depends on.