School of Packaging Sustainable Materials Group

Packaging in Transition: The Evolving Roles of Fiber/Paper and Plastics 

The packaging industry is entering a materials transition—one driven not by elimination, but by smarter material use. As fiber-based substrates gain momentum, plastics continue to play a critical role both as standalone materials and as performance enablers in next-generation hybrid packaging systems. This blog explores how paper, plastics, and circular design principles are converging to shape the future of packaging. 

The packaging industry is undergoing a transition toward smarter material use. 

Performance requirements have not changed. 

Mechanical strength still matters. 
Seal integrity still matters. 
Moisture resistance still matters. 
Oxygen barrier performance still matters. 
Cost and processability still matter. 

Plastic built the modern packaging industry because it reliably delivers these properties at scale—protecting food, pharmaceuticals, and consumer goods across both flexible and rigid packaging formats. Today, nearly one-third of all plastics produced globally are still used in packaging applications. 

At the same time, renewable fiber-based substrates—including paper and molded fiber—are gaining momentum as the industry works to improve recyclability, biobased content, and align with circular economy goals. 

These developments are often framed as competing pathways. 

In reality, they are complementary.

Fiber-Based Packaging: Opportunities and Limitations

Paper and molded fiber offer several advantages as packaging substrates. 

They are renewable. 
They are biodegradable. 
They integrate well into existing recycling streams. 

However, fiber-based materials are inherently porous. 

Uncoated fiber networks absorb liquids and allow oxygen and water vapor to diffuse through microscopic voids in their structure. This limits their use in packaging applications where shelf life, product stability, grease resistance, and contamination protection are critical. 

Historically, these limitations were addressed by laminating paper with polyethylene or polyester films, or by applying waxes, halogenated polymers, or PFAS-based sizing agents. 

While these solutions improved barrier performance, they often impaired recyclability and introduced long-term environmental persistence. 

This has led to an important engineering question: 

Can fiber-based packaging systems deliver plastic-like performance while remaining compatible with recycling infrastructure? 

In molded fiber applications, surface-engineered barrier layers support grease resistance, dimensional stability, and thermal performance without compromising formability or tooling compatibility at maximum output. 

Any next-generation packaging system—whether fiber-based, polymeric, or hybrid—must meet the packaging requirements in addition to being run at commercial speeds and precision on existing converting and filling lines to be commercially viable.

The Continued Role of Plastics 

Plastics will continue to play a critical role in packaging—both as standalone materials and as enabling components in hybrid fiber–polymer systems. 

Fiber-based substrates do not inherently provide: 

• Heat sealability 
• Moisture vapor resistance 
• Chemical stability 
• Long-term oxygen and gas barrier performance 
• Structural flexibility in thin-film formats 

These properties are still delivered reliably by polymeric materials. 

As a result, the future of packaging is evolving across three parallel domains: 

• Hybrid fiber–polymer systems 
• Recyclable solo plastics 
• Biodegradable and compostable plastics 

Hybrid fiber–polymer packaging is increasingly being explored as a transitional packaging architecture, combining structural renewability with polymer-enabled barrier performance. 

Each of these domains will serve a distinct functional role depending on application-specific performance requirements.

Hybrid Packaging: Integrating Fiber and Polymer Performance 

In hybrid packaging architectures, plastics are not being replaced—they are being redefined. 

Ultra-thin polymer coatings/layers that are recyclable or biodegradable and can provide: 

• Heat sealability 
• Moisture resistance 
• Oxygen barrier functionality 
• Mechanical integrity 
• Liquid water/oil resistance (hot and cold) 

without permanently compromising the recyclability of the fiber substrate. 

These developments include: 

• Repulpable laminates 
• Dispersible barrier coatings 
• Recyclable polymer binders 
• Fiber-compatible thermoplastic systems 

In these formats, plastics function as performance enablers—supporting packaging requirements of modified fiber/paper substrates while maintaining compatibility with recycling (and/or biodegradable) streams.

Solo Plastics in a Circular Packaging Economy 

Beyond hybrid systems, plastics will continue to serve as standalone materials in both flexible and rigid packaging formats. 

Here, the focus shifts toward: 

• High-barrier mono-material packaging 
• Recyclable or biodegradable adhesives and labels 
• Easily recyclable polymer systems 
• Biodegradable and compostable materials 
• Chemically stable resins capable of multiple reuse cycles 
• Biobased or renewable polymers 

Advances in post-consumer resin (PCR) recovery technologies, compatibilization strategies, additive stabilization, and reactive processing are improving: 

• Mechanical property retention 
• Odor reduction through deodorization 
• Color correction through decolorization 
• Melt stability across recycling cycles 

These material-level improvements are essential for enabling multi-cycle reuse of polymer packaging without significant degradation in performance. 

Emerging regulatory frameworks—including packaging recyclability requirements and extended producer responsibility (EPR) initiatives—are increasing industry interest in packaging systems compatible with circular material flows.

Materials Optimization Over Materials Replacement 

The packaging industry is not moving toward a single-material future. 

It is moving toward material optimization—deploying fibers, plastics, and renewable polymers based on performance requirements, processing constraints, and end-of-life considerations. 

In some applications, fiber-based packaging may be sufficient. 

In others, hybrid paper–polymer systems may offer the best balance of recyclability and performance. 

And in many cases, recyclable or biodegradable plastics may remain effective standalone solutions. 

Flexible films. 
Rigid containers. 
Medical packaging.  

These applications will continue to depend on polymer-based materials—even as the industry advances toward circular design principles. 

The Center for Plastic, Paper, and Hybrid Packaging End-of-Life Solutions (C3PS) was established in 2025 through support from the U.S. National Science Foundation (NSF) to address pre-competitive, industry-wide challenges in packaging sustainability. The Center brings together academic researchers and industry members to investigate materials design, processing, performance, recycling, composting, and end-of-life management across plastic, paper-based, and hybrid packaging systems. 

C3PS research focuses on improving material performance, recyclability, and process compatibility while maintaining scalability and economic feasibility within existing packaging infrastructure. 

Additional information about the Center’s research activities and industry engagement programs is available at: C3PS Circular Packaging Solutions Website