Shipping packages endure significant shock, vibration, and handling stress. Businesses must ensure products arrive in the same condition they left the warehouse. Most items do not perfectly fill a standard shipping container, leaving empty spaces, or “voids.” These voids allow the product to shift, move, and impact the box walls, which is the leading cause of product damage. The solution is the strategic use of materials designed specifically to eliminate this empty space and secure the contents.
Defining Void Fill Packaging
Void fill packaging refers to the protective material placed inside a shipping container to occupy the empty volume remaining after the product has been inserted. This material is distinct from the primary packaging that directly surrounds the item, such as a product box or wrapping. The sole mechanical function of void fill is to eliminate the empty space, thereby restricting product movement and preventing the contents from experiencing damaging momentum shifts. The goal is immobilization, achieved by firmly bracing the product against the internal walls of the outer container. While many void fill materials offer a degree of cushioning, their effectiveness is measured by their ability to prevent the item from rattling or shifting during the transport cycle.
Why Void Fill is Essential for Shipping
The application of appropriate void fill materials offers tangible business justification beyond simple product protection. By securing items and preventing the damage caused by movement, companies immediately observe a reduction in overall damage rates, which directly impacts the bottom line. Lower damage rates translate into fewer customer returns, a decreased need for replacement stock, and reduced costs associated with reshipping and processing claims.
Using effective void fill contributes to an improved customer experience. When a customer receives an intact product, their perception of the brand improves, fostering trust and encouraging repeat business. Conversely, receiving a damaged item creates dissatisfaction and can lead to negative reviews that harm brand reputation. The small investment in proper void filling acts as a defense against logistical failures and serves as an important component of overall quality control.
Common Types of Void Fill Materials
A. Air Pillows and Cushions
Air pillows are lightweight, inflatable pouches made from a thin polyethylene (PE) film, often high-density or low-density PE. These cushions are typically inflated on demand using specialized machinery, allowing them to be stored flat and minimizing warehouse space requirements. Since they consist of approximately 99% air, they add minimal weight to the final package, which helps keep shipping costs down. Air pillows are generally best suited for filling large voids in packages containing lightweight or non-fragile items, though they offer excellent shock absorption for delicate electronics and glassware as well.
B. Loose Fill (Packing Peanuts)
Loose fill, commonly known as packing peanuts, consists of small, irregularly shaped pieces of material poured into the box to surround the item. Traditional peanuts are made from expanded polystyrene (EPS), which provides a low-cost, lightweight solution that conforms well to oddly shaped objects. Due to environmental concerns, many companies now opt for starch-based or biodegradable alternatives that dissolve in water, offering a significantly better sustainability profile. The primary use for loose fill is to create a fully encapsulated barrier of protection for items with complex shapes.
C. Paper-Based Void Fill
Paper-based void fill utilizes crumpled, shredded, or fan-folded kraft paper to fill the empty space and brace the product. This material is highly effective for blocking and bracing products, especially heavier items that might compress lighter materials like air pillows. It is considered a highly sustainable option because it is often made from recycled content, is easily recyclable, and is biodegradable. Paper is often dispensed through specialized machines that crease and fold the material to maximize its volume and protective density, offering a clean, professional aesthetic.
D. Expanded Polystyrene (EPS) Foam Inserts
EPS foam inserts are custom-molded or engineered blocks of material designed to fit precisely around a specific product within a specific outer carton. This type of void fill offers a high degree of protection and superior shock absorption because it cradles the item and secures it on all sides. While the initial cost can be higher due to the need for custom tooling and design, EPS is highly effective for shipping expensive, fragile, or high-value electronics. The material itself is lightweight and fully recyclable, though recycling infrastructure for EPS can be less common than for paper or simple plastic film.
Factors for Selecting the Right Void Fill
Choosing the appropriate void fill requires a systematic evaluation of product characteristics, logistical constraints, and business priorities. The fragility of the product is the foremost consideration; a delicate glass item demands a high level of cushioning and immobilization, often requiring a denser material or custom foam. The weight of the item also matters, as heavy products require materials with high compressive strength, such as densely packed paper or robust foam inserts, to prevent them from crushing the fill material during transit.
Shipping volume and cost per package are also determining factors in the selection process. High-volume shippers benefit from automated systems, such as on-demand air pillow inflators or paper dispensers, which improve packing speed and labor efficiency. Sustainability has become increasingly important, with many businesses prioritizing options that are biodegradable, contain recycled content, or are easily recyclable by the consumer, such as paper or starch-based loose fill. This choice impacts not only environmental goals but also the brand perception of the product upon arrival.
Best Practices for Effective Void Filling
Effective void filling is a matter of technique and using the precise amount of material to secure the contents. The primary technique involves centering the product within the outer container and ensuring that there is protection on all six sides. Under-filling the void space allows the product to shift, nullifying the material’s protective function and leading to damage.
It is equally important to avoid over-filling, which can cause the box to bulge, potentially leading to material waste and increasing the risk of the box bursting or being damaged by handling equipment. When using paper, a common technique is the “H-wrap,” where the crumpled paper is placed strategically at the center and edges of the box to create a firm brace around the product. A simple test for proper filling is to gently shake the sealed package; if the contents move or rattle, more fill material is needed to achieve full immobilization.