How Balloons Are Made

Ever toyed with the question how do you make balloons? Are you simply bursting to know how balloons are made? Enough gassing. Let’s find out.

Engineering How It’s Made
28 June 2022

Colourful, bright and found in all shapes and sizes, balloons have become an icon of celebration. Whether it’s a children’s party or mass release, these stretchy inflated bags are a clear sign that fun is afoot.

This wasn’t always the case however. In fact, the road to how balloons are made today is paved with sacrifice and accidental discoveries. We’ll explore the history of our flexible friends and the science behind how they work before answering the ultimate question: How do you make balloons?

How Balloons are Made: A History

The history of balloons is not one of fun and games. In the 13th century, the Aztecs are said to have inflated animal intestines into “balloons” as sacrifices to the gods. What’s more, the journey towards how balloons are made now has tended to be a side effect of scientific experiments. For example, Galileo once inflated a pig’s bladder to test out the weight of air.

Even the actual “invention” of rubber balloons by Michael Faraday in 1924 was incidental to something else. In fact, Faraday created them a vessel to hold the hydrogen on which he was conducting experiments. This was made up of two circles of soft rubber, the edges of which would be rubbed together to adhere, the rest lined with flour to keep them apart. It was in this flat-pack form that the first toy balloons were sold by Thomas Hancock in 1925, but mass production only began in the 1930s.

How Do You Make Balloons? Materials

Producing millions of multicolored balloons which are exported all around the world (Photo: Eric VANDEVILLE via Getty Images)

Before we answer the question “how are balloons made”, let’s look at what balloons are made of. Nowadays, there are many balloon material options, including rubber, nylon fabric and Mylar or metalized plastic.

These “elastic” materials are made up of polymers, which are loosely arranged long particles. Much like a coiled spring or slingshot, polymers can elongate and stretch, for example when air is blown into a balloon, and naturally return to their original state, such as when a balloon deflates.

In terms of how balloons are made today, the most common elastic material used is latex. Not only can this be stretched to up to eight times its own size, but it’s also biodegradable. This can be synthetic, but is usually natural latex, a milky substance harvested from plants, especially rubber trees or “Hevea brasiliensis”.

How are Balloons Made in Factories?

Close-up of colour balloons (Photo: Flashpop via Getty Images)

Balloon manufacturing is highly automated. While people are there to monitor the process and add some of the materials, the vast bulk of the work is machine powered.

How Balloons Are Made: Colouring Latex

Balloons are made by dyeing, moulding and then rubberising latex. As mentioned above, most balloons are made of natural latex. In a factory setting, the liquid latex will usually be contained in a vast vat or tank installed with internal mixers. To colour the balloon, dye is added, being filtered through cheesecloth as it is poured in, thereby removing any lumps. For the next 15 to 16 hours, the dye and latex will stay in the tank, its mixers agitating the liquids. This will both ensure complete blending of the dye and prevent the liquid from clotting or curdling.

How are Balloons Made Into Shapes? Moulds

The latex for balloons is shaped using standard forms or moulds. The moulds used to shape round balloons in a factory look like neatly arranged upright baby rattles travelling on a tray. They might be set out in a grid of, say, three rows of 11 moulds each. This tray of moulds will roll from station to station, some of which contain special fixtures to flip the tray so it can be dipped into various chemicals. However, before any of this, the moulds are passed through a tunnel of hot water sprays, which wash them thoroughly.

How Balloons Are Made: Adding The Latex

The first flip and dip of the moulds is into a milky vat of coagulant that gives them an electrochemical charge. Station two is when the moulds are dipped into the dyed latex mix. The tray rolls onto a rotating fixture and is flipped upside down. The vat of coloured latex slowly rises up to immerse the moulds. This is where the electrochemical charge comes into play, attracting the latex. Once coating is complete, the vat retracts, after which the tray is returned to an upright position and rolls on.

How Balloons Are Made: Creating the Lip

Balloons being released (Photo: Howard Kingsnorth via Getty Images)

Next, the tray passes through a tunnel of rotating brushes aimed at where the balloon opening will eventually be located. The brushes cause the latex there to roll in on itself, creating the lip of the balloon where it can eventually be inflated. Next comes vulcanisation.

How are Balloons Made Strong? Vulcanisation

Also known as rubberising, vulcanisation involves dipping the moulds tray into hot water for around 16 minutes to make them more durable. As a side effect, this also removes the impurities normally associated with latex allergies. The nearly complete balloons are dipped for a final time into a water and talcum powder mix. This is to make them easier to remove from the moulds.

How Do You Make Balloons? The Final Steps

The removal is done by way of blowing air into the balloons. They pass through a tunnel with air jets beneath and rollers above. As they are inflated, the rollers are able to grab the balloons and pull them free from the moulds. They are then rolled upwards and onto a conveyor belt, which transports them into an industrial washing machine. Rolled about with a cleaning solution at 71 degrees Celsius, this acts both to clean the balloons and complete their vulcanisation.

How Balloons Are Made: Quality Control

The only thing left to do is to test and check the product. Balloons are inflated and checked for faults. This part is carried out by workers.

Well, it’s been a ball answering “how do you make balloons?” We hope it’s expanded your know-how of how balloons are made. Must fly!

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