Clariant Explores Color’s Role in a Circular Economy for Plastics

In a recent feature, Clariant’s pigment specialist Philippe Lazerme outlines how colour can thrive in a circular plastics economy without compromising recyclability or sustainability. He highlights design strategies, recycling technologies, and emerging pigment solutions that enable vibrant, safe, and eco‑friendly packaging.

Designing for Recycling

Packaging designers face a dual mandate: create eye‑catching products that reinforce brand identity while ensuring the materials can be recycled or reused without degradation. Key considerations include:

• Material selection – Choosing polymers that are compatible with mechanical, chemical, or solvent‑based recycling streams.
• Colour choice – Pigments must maintain hue and brightness across multiple life‑cycle stages, including repeated use and high‑temperature processing.
• Recyclate integration – As brands commit to higher recycled content, pigments must deliver consistent colour performance even when the base resin is a mixture of virgin and post‑consumer material.

Clariant Pigments is developing faster colour‑matching systems for recycled resins and robust pigment ranges that withstand repeated recycling cycles without compromising safety or aesthetics.

Recycling Pathways

Mechanical Recycling

Mechanical recycling accounts for roughly 80% of plastics returned to the loop. While PET bottles recycle well, other polymers and mixed‑polymer streams suffer from property loss after several cycles. Colour stability is critical: pigments must not decompose or leach toxic substances during compounding. Clariant’s expertise in heat‑stable and migration‑resistant pigments supports the industry’s need for safer, high‑quality recycled grades.

Solvent‑Based and Chemical Recycling

Emerging solvent‑based processes dissolve specific polymers, but residues can leave greyer recyclates. Chemical recycling methods—such as depolymerization with enzymes or catalysts, pyrolysis, and gasification—break polymers into monomers or fuels, producing materials that closely resemble virgin resin. In these streams, pigments can be applied in the same manner as for new plastics, simplifying the production chain.

Near‑Infrared (NIR) Sorting

Efficient sorting relies on NIR reflectance to distinguish polymer types and colours. Carbon‑black pigments absorb NIR, causing black items to be misidentified and often diverted to landfill. Clariant has engineered NIR‑reflective black pigments for HDPE, LDPE, PP, PET, PS, PA, and PVC, enabling accurate sorting and enhancing recovery rates.

Biodegradable Polymers

While still niche, biodegradable plastics are gaining traction. Colourants must meet strict impurity limits to satisfy standards such as EN 13432. Clariant’s 26‑colour organic pigment range, derived from Graphtol and PV Fast lines, meets these criteria, expanding colour options for sustainable packaging solutions.

Steps Toward a Closed Loop

With commitments from top consumer‑goods and packaging firms—over 20% of the global market pledging 100% reusable, recyclable or compostable packaging by 2025—colour will remain a cornerstone of the industry. Clariant’s ongoing research into colour‑matching, NIR‑compatible pigments, and safe, high‑performance formulations ensures that sustainability and visual appeal can coexist, advancing the circular plastics economy.