Why is milk contained in a rectangular paper box?

Beverage is an indispensable drink for us. Especially on hot days like today, it is possible to say that turning on a lid of a cool carbonated soft drink is nothing more wonderful. Besides, fresh milk is also an extremely nutritious drink that everyone is familiar with. However, a small feature that you may have missed.

Have you ever wondered: Why cans of soft drinks (cans of carbonated soft drinks, beer cans, etc.) always be round cylinders meanwhile, most boxes of fresh milk with cardboard are always shaped is box. The root cause of this difference is not really simple. The difference is not only due to technical factors, a bit of historical factors, a bit of consumer psychological logic, but this is also a classic problem in economics that economists have solved in the past.

From a technical perspective - The round shape is better than flat

This is the most common answer when someone explains the difference.Soda, beer or any kind of carbonated water contains a great pressure on the cans. As long as you shake the can of water, then open the lid, you will see how great internal pressure is. Therefore, one needs to design a can with a form that can withstand a great pressure without distortion. And the space shape chosen here is the round cylinder.

The pressure exerted on the surface of the beverage can

The main reason is that round cans are better able to withstand pressure than flat surfaces. Moreover, beverage companies can use less material to produce cans but still ensure the ability to withstand the high pressure from internal gas water. In a comparison, if a soda can is designed to be an aluminum box, one must increase the thickness of the aluminum plate by at least 3 times. This increases the amount of aluminum needed to make cans up to 8 times more than the round cylinder design.

Of course, the most fundamental principle in economics is to maximize profits, minimize costs, and because of that, soda cans in the form of round pillars are selected. A similar example is easier to imagine that the bridges crossing the river are always semi-circular instead of straight-forward design.

However, the question here is if the round cylinder has many advantages like that, why don't people apply it to contain fresh milk? If it is assumed that using the same material to make the container, the cost to produce 2 million round cylindrical cans is still far below the cost of producing 1 million cans. So why do people still use it to produce fresh milk cans?

This question needs to be approached from an economic perspective to explain. But first, look briefly at the history of fresh milk boxes.

History of canning fresh milk - From glass bottles to cardboard boxes

At the end of the 19th century there were still many dairy farmers in the United States. To supply milk to people in towns and cities that are growing very rapidly as a result of the industrial revolution, small-scale dairy farms often milk cows with their hands and put them in glass bottles. Crystal to transfer to customers.

A dairy farm in the US in the 19th century

By the beginning of the 20th century, when some farmers began to switch to milking by machines, the number of products increased and the farm size was larger than before. Now a problem arises: Refrigerators are still unpopular, people still use cooling methods with the freezer compartments from before. It was simply an insulated box and put ice inside. This is a way to keep cold and costly but not effective because the ice inside always tends to melt quickly. Another important reason is that the glass bottle used to store milk is not well insulated.

The issue of preserving milk after squeezing becomes an unsolvable problem and has no resolution at that time. The farms still apply the tradition of squeezing, delivering milk every day with glass bottles and collecting glass bottles after finishing use. This means that all homes have fresh milk to use, but drinking milk they buy fast enough to pay for bottles and milk is not damaged.

The first milk bottles were made of glass

Although there is no interdependence here, the fridges and carton boxes of milk seem to grow in parallel. The first refrigerator was tested in the 1910s. Meanwhile, although the problem of inventing a carton of milk is still controversial until now, most people see that milk cartons The cardboard was invented in 1915.

The first carton of milk was invented by John Van Wormer in 1915 and basically shaped like the one we use today. It is simply a piece of cardboard that is cut, folded and glued to the shape of a rectangular box. The first milk box is used without a lid. Instead, the first part is glued to preserve the milk inside. To this day, one layer of polyethylene paper is covered with polyethylene so that the milk inside cannot penetrate into the inner layer.

Picture of a display cabinet selling fresh milk in the supermarket

When the refrigerator was popular with every household within the next two to three decades, the cardboard milk box was also gradually used more. Even so, glass milk bottles are still in use today. However, glass bottles can only be used in some areas near the cow farm. If producing and transporting fresh milk on an industrial scale, people still use cardboard boxes instead of glass bottles because of the economic benefits it brings. Moreover, glass bottles are up to 3 times heavier than paper boxes if they contain the same amount of milk, which will cause more waste of transportation costs. And of course, glass is much more expensive than cardboard boxes.

At this point, the development history of the milk carton has told us why the fresh milk box made of cardboard is produced on an industrial scale .

Approach the problem in the context of microeconomics - Cost-Benefit Relationship

Returning to the second question: if the round cylinder has such advantages, why don't people apply it to contain fresh milk? Apparently, fresh milk has no gas inside and therefore, there is no pressure created on the bottle. However, fresh milk must be kept cold . This is the key to the problem.

Fresh milk must be refrigerated, while soft drinks are not necessary

Anyway, the cost of cooling is not cheap. From the investment cost of buying a refrigerator, the cost to maintain it to remain stable until the cost of electricity is obviously extremely expensive. Therefore, each cooling space must always be used in the most effective way. The space in the refrigerator is only used for those products that are most essential, including our fresh milk.

Therefore, the space in the refrigerator needs to be maximized in order to preserve as much milk as possible.In terms of spatial geometry, square boxes allow the largest amount of milk to be stored . Milk cans can be stacked together, there is no space left empty. Meanwhile, round boxes will waste more surrounding space . Therefore, cardboard milk boxes are designed in square shape to bring the greatest economic efficiency.

The square cross section will make the most of the space compared to the circle.

Maybe for a consumer perspective, you think that the space on the milk storage shelf in the supermarket is not really much. However, look at the problem with the perspective of a fresh milk business. The dairy company even knew that holding a "milk can" like a soda can give users a more interesting feeling. Users can turn on the lid and put "milk cans" to drink easily. However, creating a sense of comfort for users when holding in their hands is important because often, people do not drink milk directly from the box.

Even if the user drinks milk directly from the paper box, according to the principle of benefit - cost , the manufacturer should not use a round cylindrical container to store milk. Although box-shaped packaging saves shelf space, whatever it contains, space saving plays an important role in dairy products rather than beverage products. Because most supermarkets' beverages are placed on open shelves, which are very cheap and do not require any other operating costs. Meanwhile, milk is stored in the freezer, these cabinets are expensive and require operating costs. Therefore, the space on the shelves in these freezers is very valuable and increases the benefits of milk storage in rectangular cylindrical boxes. This is the opportunity cost in choosing the shape of a milk carton.

The correlation diagram between output and cost in the concept of economies of scale

Moreover, making the most of the cooling space to contain milk contributes an important part in the profit when selling milk. The more milk a retailer can store on a refrigerated shelf, this allows more milk to be sold, thereby increasing milk sales and profit margins in the dairy business. The long-term increase in margins and marginal cost reductions have contributed to economies of scale.

Obviously, no matter how much or how much milk is produced, the cost of maintaining a cold storage system is always fixed. If the amount of milk sold is small, then the cold storage cost per unit of milk will increase. Therefore, when the milk output is greater, the cold storage cost is divided equally for each unit of milk, thereby reducing a significant amount of per capita milk cost. That is the concept of "economic benefits by scale".

In addition, milk is an essential product for consumers. The amount of milk consumed is much higher than that of other beverages. Maybe, consumers are willing to spend a lot more money on a limited edition car. Limited edition is only different from the regular version in a single line on the body: Limited Edition. However, some users will be willing to pay twice as much to own it. But for an essential product like milk, the production of round boxes will incur additional material and storage costs, from which the price of each carton of milk will increase. This is not good for users.

Conclusion

Finally, we have the answer to choosing materials and shapes to produce milk cans. And the question is why the difference between fresh milk and soft drink cans has the answer.Round cylindrical form allows storage and storage of carbonated soft drink cans without deforming cans. Regarding milk box materials, the choice of cardboard is much more economical than glass bottles for storing milk. In terms of the shape of a fresh milk box, a rectangular box will create a much greater economic benefit than a round can. This benefit has been explained in detail through two economic concepts, "Opportunity cost" and "Economic benefits from scale" have been analyzed above. Today, not only milk, but also drinks that require cold storage such as juice are also boxed in rectangular form with cardboard for the same reason.

Hopefully, through the article, you can explain a more general way for the difference between milk and beverage cans. Thereby, we can see, a difference that seems small but few people pay attention, if brought to dissection with many approaches, many different perspectives will create many reasons behind it. In fact, a difference seems to be small but to explain it is really not simple at all.