Mono-material: Single-substance solutions for a true circular economy
Last updated: 13. March 2026
The term mono-material refers to products or packaging that are consistently manufactured from a single, uniform raw material family. In professional circles, this is often referred to as a single-substance solution. The direct counterpart is multi-materials or composite materials, which consist of various different layers of substances. While these are widely used, they are often very difficult or even impossible to recycle by comparison, as the separation of the components is technically extremely demanding.
Specifically in plastics technology, the term mono-material refers to solutions that contain only one specific polymer (e.g., pure polyethylene). In practice, 100% purity is often difficult to achieve due to necessary additives. However, for a package to be considered a mono-material according to current recycling guidelines, at least 90% of the total weight must generally consist of a single polymer type.
In the pharmaceutical sector in particular, high-quality polymers are used that meet the strictest requirements, such as USP Class VI. In these cases, dyes are often deliberately avoided. This not only serves the aesthetic but, above all, minimizes the risk of chemical components of the pigments migrating into the medication (leachables) and jeopardizing the stability of the active ingredient.
The advantages of single-substance solutions
Mono-materials are gaining importance across all industries because they offer tangible advantages in four areas:
Ecological and economic aspects
Single-substance solutions are the backbone of a sustainable circular economy. Their single-sort structure enables high-quality recycling, which conserves natural resources and drastically reduces the carbon footprint. Furthermore, problematic adhesives, which are necessary in composite materials to bond the layers together, are eliminated. From an economic perspective, these solutions pay off through lower disposal and sorting costs. Since no complex separation processes are required, the recycling process is quite simply faster and more cost-effective.
Strategic and technical advantages
The regulatory landscape is changing rapidly. With the new EU Packaging and Packaging Waste Regulation (PPWR), strict quotas are approaching for manufacturers. Those who switch to mono-material today fulfill these requirements in advance and simultaneously strengthen their image among environmentally conscious consumers. From a technical standpoint, limiting the process to one material type significantly reduces complexity in production. Process parameters such as temperature control can be managed more precisely, leading to more stable manufacturing processes and simpler quality control in the sense of Industry 4.0.
Challenges and the "Design for Recycling" approach
Of course, composite materials have their justification, for example, when extremely high barrier requirements against oxygen or moisture are involved. Mono-materials like PE or PP can reach their material limits here. Today, however, the trend is clearly towards "Design for Recycling": packaging is designed from the ground up to be functional while also being capable of efficient recycling at the end of its life cycle. Any barrier deficits regarding gases can be compensated for by intelligent secondary packaging (e.g., aluminum overwraps). In this way, the protection of the contents is maintained without jeopardizing the high-quality primary recycling of the container.
Application example: Use of mono-materials in BFS technology
A prime example of the consistent implementation of mono-material solutions is the Blow-Fill-Seal (BFS) technology developed by Rommelag. In contrast to traditional glass vials, which are closed with elastomer stoppers and aluminum caps (a classic multi-material mix), a BFS container consists of 100% of a single polymer family.
Even the closure is formed directly from the material of the container body during the process. This thermal welding creates a hermetic seal without any use of foreign substances such as glues. The high-quality polymer granulate can be regranulated by type after use and utilized as a valuable raw material for new applications – a closed loop in its best form.