Use the concepts of acceleration, force and yield strength to explain why delicate goods shipped in a cardboard box are often first packed in polystyrene foam.
To understand why delicate goods shipped in a cardboard box are often packed in polystyrene foam, we need to understand the concepts of acceleration, force, and yield strength.
Acceleration refers to the rate at which an object changes its velocity. In the case of shipping, the package may experience various accelerations during transportation, particularly when it is being handled or transported on uneven surfaces.
Force, on the other hand, is the push or pull acting upon an object. During transportation, packages can experience forces from various sources, such as sudden stops, impacts, or vibrations. These forces can cause the package to undergo external pressure and result in damage to the delicate goods inside.
Yield strength is the maximum stress that a material can withstand without permanent deformation. In other words, it is the amount of force or stress a material can handle before it permanently changes shape. Cardboard boxes have a relatively low yield strength compared to packaging materials like polystyrene foam.
Now, let's tie these concepts together. Delicate goods require protection from the external forces experienced during transportation to avoid damage. When delicate goods are packed in a cardboard box, the low yield strength of the box makes it prone to deformation or collapse under stress. This means that if the package encounters a sudden stop, a sharp impact, or heavy vibrations, the cardboard may bend, compress, or rip, potentially damaging the fragile items inside.
To mitigate this risk, polystyrene foam is utilized for additional protection. Polystyrene foam has a much higher yield strength compared to cardboard. When fragile goods are packed in polystyrene foam, the foam absorbs and distributes the external forces exerted on the package. The foam acts as a cushion, limiting the acceleration and impact felt by the delicate goods inside the box.
By using polystyrene foam as a protective layer, the acceleration and force experienced by the delicate goods are significantly reduced. This ensures that the fragile items remain secure during transportation, reducing the risk of damage.
Therefore, delicate goods are often packed in polystyrene foam inside a cardboard box to provide an additional layer of protection against acceleration and external forces that could potentially cause damage.