Hollow-core plastic packaging: a Reusable Packaging News hub article
From corrugated plastic sheets to bubble board and multi-layer composites, hollow-core plastic packaging has become a foundational substrate in reusable transport packaging (RTP). This hub provides an overview of material options, including the differences between polypropylene (PP) and polyethylene (PE), and highlights the packaging formats and supply chain applications where hollow-core plastics excel.
Overview
Hollow-core plastic structures offer a compelling combination of low weight, strength, moisture resistance, and long service life. These qualities make them well-suited for reusable transport systems in retail, parcel networks, automotive manufacturing, and food supply chains. While polypropylene (PP) remains the dominant material for most sleeve packs, totes, and bulk containers, polyethylene (PE) is also used by several manufacturers for dunnage, inserts, and certain corrugated or fluted sheet formats.
What Is Hollow-Core Plastic?
Hollow-core plastic refers to sheet materials with internal air channels or cells that provide rigidity without adding weight. These internal structures may take the form of twinwall flutes, bubble-style cells, or foam-filled cores. The resulting sheets exhibit excellent stiffness-to-weight performance, are easy to fabricate into reusable containers, and resist moisture far better than paper-based alternatives.
Key Material Types
Corrugated Plastic (Twinwall PP or PE)
The most widely used hollow-core format is twinwall corrugated plastic, produced in a structure similar to corrugated fiberboard. Traditionally made from polypropylene, twinwall sheets are also available in HDPE versions from manufacturers such as MDI, Primex, and Signode. PE versions offer increased flexibility and impact toughness, particularly in colder environments, while PP provides superior stiffness for larger reusable formats such as pallet sleeves and postal totes.
Bubble-Board and Laminated Core Sheets
Bubble-core and laminated boards provide smoother surfaces and enhanced rigidity. Brands such as AkyBoard® and similar composites are chosen for cosmetics, pharma, and electronics where visual finish, hygiene, and barcode/RFID readability are important.
Composite or Foam-Core Structures
For demanding applications, polypropylene foam cores are laminated with rigid skins to create boards with increased impact resistance and part protection. These structures are common in automotive dunnage, precision-part trays, and reusable packaging where surface protection and durability are critical.
PP vs. PE: Material Differences That Matter
Though PP remains the dominant resin for hollow-core reusable packaging, polyethylene also plays an important role. Each material provides distinct performance characteristics:
- Polypropylene (PP): Higher stiffness, better dimensional stability, superior rigidity for sleeves, boxes, and automation-compatible trays.
- Polyethylene (PE): Greater flexibility and impact resistance, especially at low temperatures; excellent chemical resistance; preferred for partitions, inserts, and certain fluted sheets.
- Temperature Behavior: PP softens at lower temperatures than PE, while PE stays tough in cold environments.
In practice, PP dominates large-format reusable packaging, while PE often appears in dunnage, inner packaging, protective panels, and certain custom applications.
Applications Across Supply Chains
Hollow-core PP and PE support a wide range of reusable packaging formats used in automated handling, retail distribution, automotive production, postal systems, and cold-chain operations.
Most Common Applications (Six-Part Summary)
- Reusable totes and mail trays
- Foldable distribution boxes for cosmetics, retail, apparel, and pharma
- Pallet sleeves and pallet boxes (including AkyPak® and KTP-style systems)
- Automotive dunnage, trays, and precision inserts
- Bulk bins for produce, seafood, and electronics
- Retail and industrial signage, dividers, and protective panels
Closed-Edge Technology: An Evolving Feature
Closed-edge construction seals exposed flutes to prevent contamination, moisture ingress, and edge wear. Although the concept has existed for years — including sealed-edge offerings from ORBIS, Schoeller Allibert, and others — interest is rising as hygiene, part protection, and cleanability become more important.
Recent enhancements such as Corplex’s closed-edge technology for AkyPak® sleeves illustrate how sealed edges improve washability, prevent water intrusion, reduce particulation, and provide operators with smoother and less abrasive handling surfaces. These attributes benefit food, pharma, cosmetics, and high-visibility retail applications.
Sustainability and Circularity
Hollow-core PP and PE support circular packaging objectives by enabling dozens or hundreds of reuse cycles. Their mono-material construction simplifies recycling at end of life. In closed-loop environments, these materials often deliver lower total cost of ownership than single-use corrugated or molded plastics. Asset refurbishment — replacing panels, hinges, or sleeves — further extends lifecycle value.
Industries Using Hollow-Core Plastic
A wide range of markets depend on hollow-core plastics for reusable transport packaging:
- Food & Fresh Produce: moisture resistance and easy sanitation
- Cosmetics & Pharma: smooth, cleanable surfaces and hygiene compliance
- Electronics: low particulation and compatibility with automation
- Automotive & Industrial: durable dunnage and standardized reusable trays
- Postal & Parcel: lightweight, rigid trays for high-speed systems
FAQ: PP vs. PE in Hollow-Core Plastic Packaging
Is “hollow-core” the correct term?
Yes. The term hollow-core plastic is widely used across reusable packaging to describe fluted, bubble-cell, and internal-channel sheet structures. “Hollow-wall” appears occasionally, but it is less standardized and can be confusing.
What is the main difference between polypropylene (PP) and polyethylene (PE) in hollow-core packaging?
PP dominates hollow-core sheet production because it provides greater stiffness, better dimensional stability, and cleaner forming.
PE is more flexible and impact-friendly, making it useful in certain specialty or cold-temperature applications.
Why is PP typically preferred for fluted/twinwall structures?
PP is generally chosen for fluted designs because it offers:
- Higher stiffness for improved stacking
- More uniform flutes for predictable performance
- Clean die-cutting, creasing, and welding
- Better printability
- Reliable performance in automation
These qualities make PP ideal for totes, sleeves, boxes, and postal trays in closed-loop systems.
Where does PE have advantages?
PE’s softer, more ductile nature makes it valuable for:
- Cold environments such as freezers or winter operations
- Applications with frequent impacts or bending
- Protective or flexible inserts
- Blended-layer sheets where a softer surface layer is preferred
Can hollow-core sheets be made entirely from PE?
Yes. Companies such as MDI and several global extruders produce PE-based fluted sheets. These work well in applications needing flexibility, but they naturally offer less stiffness and load-bearing capacity than PP.
They are typically chosen for niche or specialty use cases rather than mainstream reusable transport items.
Which material performs better for hygiene and moisture?
Both PP and PE resist moisture, but PP hollow-core tends to dry more quickly and maintains better dimensional stability, especially in repeated wash cycles.
As a result, PP is widely used in food, produce, pharmaceutical, and hygiene-critical systems.
Which material is better for recycling and circularity?
Both resins are recyclable, but PP has a practical advantage: most returnable transport item (RTI) systems already standardize on PP.
This simplifies mono-material recycling streams and end-of-life consolidation.
So, which should companies choose for reusable hollow-core packaging?
PP is typically the best choice for:
- Reusable totes and trays
- Sleeve packs and pallet boxes
- Automated warehouse handling
- Precision dunnage and industrial protection
- Cosmetics, pharma, and electronics
PE is often selected when:
- Flexibility is more valuable than stiffness
- Cold-temperature impact resistance is critical
- Soft-surface handling is preferred
- A blended PP/PE structure can optimize performance
Both materials have strengths, and in practice, the choice depends on the specific use case, container design, handling environment, and durability expectations.
Recent Related News
Related Reading & Spokes
Sleeve Pack Shipping Systems and Their Rising Popularity
Sleeve Packs: Customization, Sustainability, Cost Savings in Bulk Packaging
Understanding Molding Processes Used for Reusable Transport Packaging
Reusable Transport Packaging: The Smart Shift Toward Circular Supply Chains
Reusable Packaging Explained: 8 Pillars That Are Shaping the Future of Circular Supply Chains
8 Takeways from the Corrugated Plastic Roundtable
Rick LeBlanc, EMBA, is the founder and editor of Reusable Packaging News (subscribe to the free newsletter) and editor of Western Pallet Magazine. A supply chain journalist with more than 30 years of experience, he specializes in pallets, reusable packaging, material handling and related operations. Rick is co-author of Pallets: A North American Perspective and Pallets & Progress: A Collected History of Pallets and Palletized Handling 1922–1945. He is also an advisory board member of the Virginia Tech Center for Packaging and Unit Load Design. Read Rick’s full bio.
