Cushioning

Package cushioning is used to help protect fragile items during shipment. It is common for a transport package to be dropped, kicked, and impacted: These events may produce potentially damaging shocks. Transportation vibration from conveyors, trucks, railroads, or aircraft can also damage some items. Shock and vibration are controlled by cushioning so that the chance of product damage is greatly reduced.

Cushioning is usually inside a shipping container such as a corrugated box. It is designed to deform or crush to help keep levels of shock and vibration below levels that may damage the product inside the box. Depending on the specific situation, package cushioning can often be between 50 and 75 millimeters (two to three inches) thick.

Internal packaging materials (sometimes the same ones used for cushioning) are also used for functions other than cushioning. Some are used just to immobilize the products in the box and to block them in place. Others are just used to fill a void and do not have a cushioning function.

When designing packaging, the choice of cushioning may depend on many factors:

Loose fill – Some cushion products are flowable and are packed loosely around the items in the box. The box is closed to tighten the pack. This includes expanded polystyrene foam pieces (Foam peanuts), similar pieces made of starch-based foams, and common popcorn. The amount of loose fill material required and the transmitted shock levels vary with the specific type of material.

Paper – Paper can be manually or mechanically wadded up and used as a cushioning material. Heavier grades of paper provide more weight-bearing ability than old newspapers. Creped cellulose wadding is also available. (Movers often wrap objects with several layers of Kraft paper or embossed pulp before putting them into boxes.)

Corrugated fiberboard pads – Multi-layer or cut-and-folded shapes of corrugated board can be used as cushions. These structures are designed to crush and deform under shock stress and provide some degree of cushioning. Paperboard composite honeycomb structures are also used for cushioning.

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Wikipedia