Having lived for decades in the world, everyone must have drank carbonated soft drinks or mineral water in plastic bottles. And if you pay attention, you will see that most of the bottom of the bottle is always designed to be bumpy, never flat like a glass bottle.
Many people will think that manufacturers must do that to highlight their products? However, this is considered a rule that most beverage companies, especially carbonated soft drinks, must follow.
The bottoms of carbonated soft drinks bottles are uneven.
Plastic soda and mineral water bottles almost all have convex bottoms, not flat like glass bottles.
As you can see, the bottom of this plastic bottle usually has 5 protrusions in the form of folds. Their effect is to increase the “strength” of the entire water bottle. Let’s take an example with a sheet of paper, you can easily fold them normally. However, if you roll them up and then fold them, it will be much more difficult. Thus it can be seen that bending any material will contribute to an increase in its strength and stiffness (or in physics known as an increase in the moment of inertia around the bending axis ).
The effect of this concave bottom is to increase the “strength” of the entire water bottle.
The effect of this design is to increase the strength of the entire water bottle based on the moment of inertia around the bending axis.
Most plastic soft drink or mineral water bottles are served chilled and have gas added inside. When the liquid is cooled and gaseous, its volume changes resulting in the bottle being subject to a great deal of pressure. Therefore, manufacturers have to design such that the corner or top of the bump at the bottom of the bottle can expand or contract to withstand this.
With this shape of the bottom of the bottle, you can only deform the top of the bottle while the bottom is very difficult.
These details can expand or contract to help regulate the pressure of the liquid inside the bottle.
In addition, the fact that the bottom of the bottle has such protrusions also contributes to absorbing shocks when you accidentally drop the bottle to the ground. If you don’t believe it, you can immediately take out a plastic bottle and crush it. Surely you can only deform the top of the bottle while the bottom is very difficult.
Besides, if you notice, you also see that beverage bottles tend to decrease in size towards the top of the bottle. This helps to lower its center of gravity , which combined with the uneven bottom of the bottle further improves the stability of the entire bottle. Even soft drink cans have bottoms that bend inwards to achieve this purpose.
Beverage bottles tend to decrease in size towards the top of the bottle.
In addition, this bumpy bottom also helps minimize shock when you drop the bottle on the ground or when something runs over the bottle.
So now you understand why plastic bottles of carbonated water have a bumpy bottom, right?