Plastic Cup De-inking
The Path to Sustainable
Recycling for Printed Cups and Labels
Printed coffee, tea, and bubble tea cups with logos or designs play a crucial role in building brand identity. However, once these containers are used and enter the recycling stream, the very inks that made them stand out can become a significant factor affecting the quality of the recycled plastic. If the ink remains on the plastic during the melting phase, pigments and specific components of the ink can contaminate the plastic material, impacting its color, consistency, and the potential applications for the recycled material
De-inking, or the process of removing printing ink from plastic, is therefore gaining significant traction in the packaging industry. It serves as a method to improve the quality of recycled materials and promote the efficient use of resources
But how does this process work? Can it truly be applied to printed plastic cups? And why is the selection of printing inks critical to the future of packaging recycling?
IN THIS ARTICLE
What Is De-inking and How Does It Relate to Plastic Recycling?
De-inking is the process of separating or removing printing ink from the surface of plastic during the preparation of materials for recycling. This is done to minimize contaminants that could negatively affect the quality of the recycled plastic
In Mechanical Recycling, plastic packaging goes through essential steps such as sorting, shredding, washing, and remelting into recycled plastic pellets, categorized by material type (e.g., PET or PP)
When printed plastic cups enter this process, any ink adhering to the surface may proceed into the melting phase alongside the plastic material. If not properly removed, pigments and certain compounds within the ink can cause the recycled plastic to become discolored, inconsistent in color, or otherwise compromised in quality. This ultimately limits its suitability for manufacturing new products
Ink removal, therefore, plays a vital role in reducing contamination before the melting stage. Some processes utilize alkaline washing combined with surfactants, temperature control, and mechanical friction to detach the ink from the surface. However, the efficiency of de-inking depends heavily on the type of plastic, the specific ink formulation, and the washing conditions of each individual system. It is not a one-size-fits-all solution for every type of packaging
Why Does Printing Ink Affect the Quality and Value of Recycled Plastic?
Printing ink is essential for adding color, design, and branding to packaging. However, during the recycling process, any residual ink on the material can alter the properties of the resulting recycled plastic. This is especially true for recycled plastic pellets that require color consistency and high quality. Ink contamination may limit the use of the material in certain types of products. Therefore, minimizing ink contamination is crucial for businesses across multiple sectors:
For Brand Owners: Design Packaging with Recycling in Mind
Brand owners can strategize the visual appeal of their packaging alongside selecting materials and printing methods that are compatible with recycling systems right from the start. Considering these elements during the design phase helps brands prepare for evolving packaging regulations
For Printers and Packaging Manufacturers: Elevate the Importance of Ink Selection
Printing ink’s role goes beyond just providing color or clarity; it must also be compatible with the substrate, the production system, and the packaging specifications. Recyclability data should be considered an additional factor alongside the ink’s adhesion, drying, and durability properties
For the Recycling Industry: Increase Opportunities to Maintain Material Quality
Reducing ink contamination can enhance the likelihood of producing recycled plastic pellets with consistent quality, thereby expanding the range of products they can be used for. However, it is important to note that the final quality of recycled plastic is also dependent on the sorting process, the cleanliness of the raw materials, and the overall recycling system
Can Printed Plastic Cups Really Be De-inked?
Currently, there are ongoing studies and trials focused on removing ink from various types of plastic packaging, including plastic films, printed labels, and containers with direct surface printing.Laboratory-level studies have demonstrated the feasibility of separating ink from plastic under optimal conditions. However, success in a laboratory setting does not guarantee that the process is immediately ready for industrial-scale deployment.Implementing de-inking in a real-world scenario requires consideration of multiple factors, such as material diversity, the volume of printed packaging entering the system, machinery efficiency, washing costs, and post-process chemical management. Specifically, the recycling of post-consumer plastic cups with direct printing faces challenges regarding material collection and the cost-effectiveness of the process.Therefore, the development of robust de-inking systems demands collaboration among recycling process developers, packaging manufacturers, and stakeholders throughout the supply chain
How Does the EU PPWR Relate to the Future of Plastic Recycling?
The European Union has introduced the Packaging and Packaging Waste Regulation (PPWR) under Regulation (EU) 2025/40.This regulation is generally applicable from August 12, 2026, with certain provisions taking effect in subsequent phases
A key element is that packaging must be designed for recycling, and the regulation sets minimum targets for post-consumer recycled (PCR) plastic content in the packaging it covers
Minimum Recycled Plastic Content Targets under PPWR:
| Plastic Packaging Type | 2030 Target | 2040 Target |
|---|---|---|
| Contact-sensitive packaging predominantly made of PET (excluding single-use beverage bottles) | 30% | 50% |
| Contact-sensitive packaging made of other plastics (e.g., PP) (excluding single-use beverage bottles) | 10% | 25% |
| Single-use plastic beverage bottles | 30% | 65% |
| Other plastic packaging types (under Article 7*) | 35% | 65% |
*Note: These targets are based on Article 7 of Regulation (EU) 2025/40. The first targets apply from January 1, 2030, or three years after the implementing act on the calculation method enters into force, whichever is later. Exemptions apply to certain packaging types
The PPWR does not directly require de-inking for all packaging types. Instead, it focuses on recyclability and the use of recycled plastic under the relevant requirements
For packaging manufacturers, preparation should begin with material selection and designing components that are compatible with existing, real-world recycling systems. This includes carefully evaluating the impact of printing inks and labels
Zeller+Gmelin and the Study of Ink Removal from Plastic
Zeller+Gmelin, a manufacturer of printing inks and coatings from Germany, specializes in printing inks for the label and packaging industry, covering UV Flexo, UV Offset, and UV Dry Offset systems
Beyond developing inks for production processes, the company has explored the feasibility of removing ink from plastic, in both shrink sleeve applications and directly printed containers. These studies serve to prove the working principles in a laboratory environment and do not constitute a confirmation that a commercially available ink removal product or system is ready for industrial use
For practical implementation, the process must be tailored to the machinery, material conditions, and specifications of each individual recycling facility. This underscores that advancing the recycling of printed plastics requires a deep understanding of both printing inks and the capabilities of downstream recycling systems
Choosing the Right UV Printing Inks
for Plastic Cups and Labels
While ink removal still faces practical limitations in real-world applications, selecting inks suitable for the material and production system remains a critical starting point for manufacturing high-quality packaging
Zeller+Gmelin offers printing inks for labels and preformed plastic containers. Key examples of relevant products include:
UVAFLEX Y80 — UV Flexo Printing Ink for Labels and Shrink Sleeves
UVAFLEX Y80 is a printing ink designed for non-food applications, specifically developed for UV Flexo systems
According to manufacturer data, its key features include high color intensity, good adhesion, and a low tendency for ink layer curling. It is well-suited for self-adhesive labels, shrink sleeves, and wrap-around labels, in accordance with usage specifications
UVAROLID UV — Printing Ink for Preformed Plastic Containers
UVAROLID UV is a printing ink for UV dry offset systems (also known as UV form printing), used for printing designs onto preformed plastic containers
The manufacturer highlights its color intensity, ink surface durability, and broad operational window. Its application on plastic cups is subject to market limitations and the specifications detailed in the product information
Both series are examples of inks developed for specific printing applications. They are not categorized as "de-inking products" and should not be interpreted as being removable in all recycling systems
Assessing suitability for recycling necessitates evaluating additional information regarding the ink formulation, the printing substrate, and the relevant recycling processes
Assessing suitability for recycling necessitates evaluating additional information regarding the ink formulation, the printing substrate, and the relevant recycling processes
How to Design Plastic Cups and
Labels for Optimal Recycling
Developing packaging to support recycling should commence at the design stage, taking into account the materials and all related components
Select Materials Compatible with Recycling Systems
PET, PP, and PE packaging possess different properties and require distinct sorting processes. Using a mono-material approach can simplify material separation in some cases, but closures, labels, adhesives, and coatings must also be evaluated in conjunction
Design Labels That Do Not Interfere with Sorting
Labels that cover an excessive portion of the surface can interfere with near-infrared (NIR) optical sorting machines’ ability to identify the plastic type. Therefore, selecting the appropriate label size, color, and film type should align with Design for Recycling guidelines specific to each packaging type
Consider Printing Inks and Washing Processes
While the adhesion and durability of ink during use are essential for packaging quality, they are not direct indicators of the ink’s removability during recycling. Evaluating "de-inkability" requires testing under conditions that accurately reflect actual recycling processes
Frequently Asked Questions About De-inking
What is plastic cup de-inking?
It is the process of removing printing ink from the plastic surface during material preparation for recycling. The goal is to reduce ink contamination and improve the chances of maintaining the quality of the recycled plastic
Can ink be removed from plastic cups printed with a logo?
Studies and trials have shown feasibility under controlled conditions. However, the success of the process depends on the ink formulation, the type of plastic, and the washing methodology
Can all types of UV printing ink be removed from plastic?
No, not all types. Because each ink formulation has different components and properties, appropriate test data is required before determining its de-inkability
Does the EU PPWR require de-inking?
No. It does not directly require this process, but it does set requirements regarding recyclability and the proportion of recycled plastic for relevant packaging
Can de-inked plastic be used straight away to make food packaging?
Not automatically. The source of the material, the recycling process used, and compliance with safety regulations for food contact materials must still be rigorously evaluated
The Future of Recycling Starts with Selecting the Right Materials and Inks
Designing packaging for recyclability is not reliant on a single step like ink removal. It requires a holistic approach that considers material type, ink formulation, printing method, and end-of-life material management together. Although de-inking currently faces limitations for certain applications, ongoing research and development highlight the critical importance of evaluating the impact of printing inks right from the source
Press Systems Group (PSG), the authorized distributor for Zeller+Gmelin printing inks and coatings from Germany, is ready to provide consultation on selecting the appropriate printing inks for the label and packaging industry. We consider the materials, printing systems, and specific needs of your production line
Looking for printing inks for plastic cups or labels?
Learn more about choosing the right printing ink for your production in the article "Plastic Cup Printing Inks: How to Choose the Right Ink for Printing and Food Packaging"Explore Zeller+Gmelin printing ink products | Consult the PSG team
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