Internal Packaging

Internal packaging provides shipment protection during the distribution process. Good internal packaging should have the ability to protect the product from shock and vibration, and then return to its original shape to provide further cushioning. There are a number of internal packaging materials and methods to consider before shipping a package.

Internal Packaging Materials

Loose Fill
Primarily used as space fillers for lightweight items. This type of internal packaging is not recommended for use with flat, narrow, or dense products that may migrate within the package. Because loose fill may shift and settle during the distribution process, the product can shift within the package, exposing it to a higher probability of damage. The minimum guideline for loose fill materials is to use a minimum of two inches (5.08 cm) around all sides of the container. In addition, the package will need to be overfilled slightly to allow for shifting and settling. Loose fill materials such as Expanded Polystyrene Peanuts cause static electricity and may damage electronic items. Anti-static peanuts should be used for electronic items. Use plastic bags, bubble sheeting, or other items to wrap the item so peanuts will not work themselves into areas that may cause harm to your merchandise.

Encapsulated-Air Plastic Sheeting
Packing material made of air bubbles that are encased between two poly sheets as they are sealed together. This process allows encapsulated air to provide a cushion to protect against shock. Encapsulated air provides good cushioning for lightweight items, is flexible, and cuts to wrap virtually any shape or size product. It should not be used to wrap heavyweight products. When using encapsulated-air plastic sheeting, use several layers to ensure that the entire product is protected, including corners and edges.

Polyethylene Foam Sheeting
Lightweight, soft, resilient foam sheeting material that provides excellent surface protection and cushioning properties. Ideal for protecting lightweight items.

Inflatable Packaging
Inflatable packaging uses air pressure to secure and hold products in place inside the shipping container, and provides an air barrier of cushioning. Extreme climate conditions will affect the amount of air pressure in the bags. In extremely cold conditions, the volume of air will decrease, causing extra space inside the package and increasing the risk of product damage. Extremely hot conditions will cause the air bags to expand, which can create stress on the seam of the shipping container.

Altitude variations can also affect the volume of air inside the air bags. Traveling from high to low altitudes (for example, packaging a shipment in Denver, Colorado, and shipping to New Orleans, Louisiana) will cause the air bags to decrease in size, and traveling from low to high altitudes will cause the air bags to increase in volume.

Foam-in-place/Foam-in-bag is formed by a chemical mixture that expands and forms a protective mold around contents. Foam-in-place forms a mold around any product, supports corners, protects edges, and is useful where cushioning is needed. For maximum effectiveness, the foam-in-place must be evenly distributed around the items. Otherwise, the foam will not protect the product. Select the appropriate density of foam to meet packaging needs, which can range from void-fill applications to high-performance cushioning.

Kraft Paper
Kraft paper (not newspaper or newsprint) is wrapped and crumpled to fill empty space inside a package with light-to-medium weight, non-fragile items. When using kraft paper, tightly wad the paper and use at least two inches (5.08 cm) around and between the contents. Make sure that there are at least two inches (5.08 cm) of kraft paper on all six sides of the box.

Paper Cushioning
Multilayered paper (not newspaper or newsprint) padding is ideal for wrapping medium to large sized, non-fragile items and those that may require moisture absorption. Paper cushioning is excellent for filling empty spaces.

Expanded Polystyrene Foam (EPS)
EPS is a moldable, lightweight, low-cost foam with minimum impact cushioning abilities. EPS is often designed with ribs that will compress on impact and return to its original shape. It is not as resilient as other poly foams, such as polyethylene and polyurethane. EPS is well suited for less fragile shipments.

Polyethylene Foam (PE)
PE is a low-density cell foam. Molded or fabricated PE offers superior shock and vibration reduction capacities, making it suitable for cushioning high value or fragile items.

Polyurethane Foam (PU)
Polyurethane is a low-density, flexible foam that offers good shock absorbency and resiliency. Because it is a lightweight, flexible foam, it is more suitable for light loads.

Corrugated Board
Two or more layers of single- or double-wall corrugated board may be laminated together to form blocks or pads. These pads can be used to form a protective shield between the product and container. Corrugated pads are best used with heavy, semi- to non-fragile products. Corrugated board can be shaped to form trays, liners, partitions, and other package accessories that work to cushion semi- to non-fragile products and increase the integrity of the shipping container.

Cushioning Methods


Blocking and Bracing
By using a resilient material, you can block and brace shipments by absorbing the shock energy and direct it towards the strongest point of the product. The blocking and bracing method is the preferred cushioning method for heavyweight packages.

Floatation is a method of surrounding an object with small pieces of cushioning material that shift or flow to fill empty space in the package and distribute the impact over the entire surface of the product.

Using sheet material of various types, individual pieces are wrapped to protect small items. This method is not adequate for the protection of heavyweight products.

Suspension is a method of holding the packaged product away from the sides of the container for protection. Materials used for suspension are straps, tape, slings, poly-film, or other supports that can act as flexible restraints.

Molded Enclosures
Molded enclosures form to the shape of the product and distribute the force across the product.