Before the 2028 Recycling Rules Take Effect, Adhesives Are the Biggest Challenge for Automotive Interior Components

The EU's new ELV Regulation ((EU) 2026/1738) came into effect on August 13 this year and will formally apply in September 2028. The requirements are clear: the recycled content of plastics in new vehicles must be at least 15% within six years and 25% within ten years, with at least 20% required to come from closed-loop recycling of end-of-life vehicles. The regulation also requires vehicles to be designed for easier dismantling and recycling from the design stage.

But what is really holding back the recycling of automotive interior components is not the proportion of recycled plastic. It is the manufacturing process. Instrument panels, door panels, armrests and other components traditionally consist of three layers: a skin, a foam layer, and a substrate. These layers are bonded together with adhesives. At the end of a vehicle's life, the three different materials are difficult to separate and can only be landfilled or incinerated as a whole.

Adhesives are the biggest obstacle to recycling automotive interior components.

1. Why Traditional Interior Components Are Difficult to Recycle

A typical instrument panel consists of three layers: the skin, made of TPO, PVC, or genuine leather, provides the desired touch and appearance; the foam layer, usually PU, provides softness; and the substrate, typically PP or ABS, provides structural strength. The three layers are bonded together using adhesives or flame treatment.

This process has been used for around 20 years, and its tactile performance and cost efficiency are well established. But the problem is that the adhesive locks different materials together. During end-of-life vehicle dismantling, interior components either have to be shredded as a whole or incinerated. Once shredded, the mixed materials cannot be effectively separated, while incineration can generate VOCs. When analyzing seat recycling, Covestro directly identified adhesives as a key reason why multi-material assemblies are difficult to separate at the end of their service life.

2. Why Traditional Interior Components Are Difficult to Recycle

A typical instrument panel consists of three layers: the skin, made of TPO, PVC, or genuine leather, provides the desired touch and appearance; the foam layer, usually PU, provides softness; and the substrate, typically PP or ABS, provides structural strength. The three layers are bonded together using adhesives or flame treatment.

This process has been used for around 20 years, and its tactile performance and cost efficiency are well established. But the problem is that the adhesive locks different materials together. During end-of-life vehicle dismantling, interior components either have to be shredded as a whole or incinerated. Once shredded, the mixed materials cannot be effectively separated, while incineration can generate VOCs. When analyzing seat recycling, Covestro directly identified adhesives as a key reason why multi-material assemblies are difficult to separate at the end of their service life.

3. Asahi Kasei's Solution: Same Material Family + Core-Back Injection Molding + Chemical Bonding

In September this year, Asahi Kasei showcased an S.O.E.™ TPE solution. The core idea is to use the same material family for the skin and foam layer, form the component through a single core-back injection molding process, and achieve interlayer bonding through chemical bonding without the need for additional adhesives.

The specific process is as follows: First, a styrene-based TPE skin is injection molded. The mold then retracts through a core-back process, after which foamed TPE from the same material family is injection molded onto the back of the skin. The two layers chemically bond at the molecular level, eliminating the need for adhesive.

The advantages of this solution directly correspond to the requirements of the ELV regulation: using a unified material family means that the component can be recycled as a whole at the end of its service life without the need for dismantling and material separation; single-process molding eliminates adhesive spraying and drying operations; and reduced material usage lowers manufacturing complexity.

Asahi Kasei has been developing this SEBS grade since 2024, targeting soft-covered components such as instrument panels, door panels, armrests, and center consoles.

4. This Is Not Just About One Company

Asahi Kasei's approach is not an isolated case. Covestro is also promoting a Desmopan TPU nonwoven seat solution, which similarly focuses on adhesive-free hot-press lamination and recyclability. Bayer MaterialScience and SABIC are also promoting solutions focused on low VOC emissions and recyclable interior materials.

These developments all point in the same direction: after the ELV regulation takes effect in 2028, the "adhesive-bonded composite" process route that has been used for two decades may gradually be replaced in automotive interior components by "the same material family + physical/chemical self-bonding."

For Tier 1 suppliers, the preparation required now is not simply to switch to another material supplier, but to reassess their manufacturing process routes: which components can be redesigned for core-back injection molding, which components still require adhesives, and how cost and yield can be balanced after making these changes.

This shift in cockpit interaction and interior component design is placing higher demands on materials, manufacturing processes, and supply chain collaboration efficiency.

Source: Automotive Interior & Exterior Industry Circle; Author: Automotive Interior & Exterior Ecosystem Circle