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How Balloons Are Made

How Balloons are Made

Oh, how I love the smell of latex in the morning!
– Sean O’Kelly

How Latex Balloons Are Made: General Overview

THE NATIONAL LATEX PRODUCTS COMPANY
OVERVIEW OF HOW BALLOONS ARE MADE

Balloons are manufactured from a liquid rubber called latex. The balloon gets its color from the pigment that is added to the latex. Pigments are both organic and inorganic compounds that absorb certain wavelengths of visible light and reflect others. For example, a red balloon is red because the balloon absorbs all the visible light except red frequency light which is reflected back to the eye.

The strength of balloons can be affected by the pigment if the pigment particle is large in size and interferes with the film continuity and if the pigment reacts with any of the other ingredients in the balloon. As far as which color has the most effect on the balloons strength, we have not done any in depth study. Since we use pigments that are water dispersions of very, very, small particle size, and they do not react with any other ingredients in the latex, we do not detect any difference.

The natural rubber latex that we use comes from the sap of the rubber tree , Heveabrasiliensis, that grows in Malaysia. This sap looks like milk and is shipped to America in large ocean tanker ships. Once removed from the tree, the sap is called latex. To make this suitable for balloon production, curing agents, accelerators, oil, color, and water must be added. After these are added, the completed latex is put in an open top tank, and the balloon form, which is in the shape of a balloon, is dipped. Before the form is dipped into latex, it is dipped into a coagulent that causes the rubber particles of the latex to collect on the form. This coagulent is calcium nitrate, water, and/or alcohol. After the coagulent coated form is dried, it is then dipped into the compounded latex. Then the latex coated form passed through a set of revolving brushes that rolls the balloon neck into the bead that is used to aid in the inflation of the balloon. The latex coated form is then washed in hot water to remove any unused nitrate. Following the leaching, the form is put in a 200-220 degrees Fahrenheit oven to cure for 20-25 minutes. When cured, the rubber balloon is removed from the form (stripped).

Balloon dipping industrial line. Balloon molds emerging from vat of red latex. Photo copied from the Latex Engineering B.V., a company that has been producing balloon and other product dipping lines for over 50 years.

The following information is taken from the Latex Engineering web site: A good balloon has the following conditions: regular peripheral wall thickness, good end gelation, pinhole free, good bead rolling, and a ‘favourable’ taste.

The above are controlled by: surface tension control of coagulant and good antisettling of ‘chalk’, even speed immersion and withdrawal with still liquid surface, correct compound viscosity and correct chemical stability, clean formers and efficient filters good step back of film thickness, well-leached film, and dryness state chemically friendly formula.

An even latex film depends upon a consistent coagulant deposit. This, in turn, depends upon a fast drying time and an even speed of withdrawal from the coagulant (which implies a hot coagulant and former). With small time cycles leading up to the coagulant dip, it is important not to lose heat necessarily after the stripping.

For making a balloon, the formers pass the following stages:

  • acid bath needed once every eight hours (or after every round )
  • clean water bath of constantly refreshed water
  • brushing, especially the former bottom
  • warming the bath up to 70 to 80 degrees Celcius
  • first coagulant bath, for beading the edge of the balloon
  • second coagulant bath for the balloon (the temperature of both coagulant baths is 70 degrees Celcius)
  • oven for drying coagulant
  • latex dip (former is leaving the bath upright in a good sliding angle – system of batch dipping – to prevent drop forming on the end of the balloon
  • oven for setting latex film
  • beading
  • leaching
  • detack tank
  • two ovens with a temperature 80 to 90 degrees Celcius, other (higher) temperatures possible
  • cooling down by two fans
  • stripping by air and rollers

The following questions apply to the manufacturing of latex balloons.

Q: Is the balloon manufacturing process all automated?
A: It is largely automated these days.
Q: How much does a typical balloon cost to produce?
A: Each balloon size and type will have a different cost. It’s a combination of the amount of latex used, and how easy it is to automate the process. 260’s are harder to make than 11 inch rounds.
Q: After the molds are dipped into the latex, how does the balloon come off its mold? (manual removal or automated process?)
A: It depends on the size and shape of balloon. Some are completely automated. Some are stripped manually (with the help of forced air/water on the form). I believe all current latex manufacturers can strip all of their round balloons automatically.
Q: This question may sound weird, but can you bond/fuse two balloons together, or say, two dried strips of latex together?
A: This is getting into an area I know less about. I can tell you from experience that balloons can stick together if heat is applied, but they dont’ hold together very well and can be pulled apart. During manufacture, if you stick them together prior to curing them, they will fuse. This is what happens with the 6-inch hearts and 260’s that are stuck together at the tips. the forms are too close together on the racks that get dipped, so after dipping, they sometimes touch each other and join.

I believe inner tubes and tires are butyl rubber (because it is oil resistant), you can probably glue latex balloons together using tire patch cement. It comes in little tubes all the way up to gallon cans. Heat is used in some types of tire patching (hot patches).

How Latex Balloons Are Made: 260 balloons

Making a 260 involves dipping a mold (the same shape as the inside of a 260) into liquid latex. Once they’re dipped in liquid latex, they are not allowed to cool. The dipped forms go through a vulcanizing oven, the nozzles are rolled, the balloons are washed, and then they’re allowed to return to room temperature and pulled off the mold (stripped). 260’s are not easy to produce; the mechanical action of making the 260 affects the final product.

How the latex runs on the mold as you pull it out of the liquid affects the eveness of the wall of the balloon. As you pull the mold out, the viscous latex is going to run (a little or a lot, but it is going to run).

If the mold hangs straight down, the wall of the 260 is thinner at the top, thicker at the bottom. The nozzle will be weaker and fatter, the end of the balloon will be stronger and thinner. If the mold hangs straight down as it dries the balloon will blow up straight. If the mold is turned over as the latex runs, the wall is more even from end to end but one side is a little thicker than the other. This 260 balloon will blow up with a curve. The drip that collected on the end of the mold as it came out of the latex runs down one side.

When you blow up a 260 you can tell how it was made. I assume the older balloon making equipment let the mold hang straight down. Mechanically, it is less expensive. To make balloons that are more even from top to bottom, a manufacturer has to invest in fancy and expensive equipment. To make a really good 260, the mold would need to spin as it turned over. This would give the best chance at an even walled 260.

The quality of the raw latex, how well it has been cleaned, the amount of vulcanization, the type of color and finish, the kind of powder, and variations in temperature and humidity during manufacturing all combine to make every batch of balloons different. How well the manufacturer balances the elements with the tools he has determines his consistency.

Balloon Forms and Molds

Balloon molds are arranged into rows and dipped into liquid latex in assembly line fashion. (see photo above) A balloon mold for a round balloon is shaped like an inverted light bulb. A 260 mold is long and thin. The Qualatex Geo Patent, which explains the process for creating Geos.

Pioneer Balloon Company display of balloon molds for Qualatex airships, twisting balloons, and novelty balloons. Pioneer Balloon Company display of balloon molds for Qualatex hearts, donuts, and blossom geos.
Pioneer Balloon Company display of balloon molds for Qualatex airships, twisting balloons, and novelty balloons. Pioneer Balloon Company display of balloon molds for Qualatex hearts, donuts, and blossom geos.

How the Rolled Lip on Balloons is Formed

Each balloon mold is the shape and size of the uninflated balloon. For example, a balloon mold for a round balloon is shaped like an inverted light bulb. The molds are arranged into rows and dipped into liquid latex in assembly line fashion. The latex at the top (thin) end of the mold becomes the “lip” when it is rolled down (toward the wide end) by a device which looks like a small motorized brush. As the rows of molds progress down the line, they pass between rotating, cone shaped brushes that are positioned horizontally, one on each side of each row of molds, pointing at the approaching molds. The brushes turn in opposite directions and are positioned so they touch the molds on each side. The point of the brushes start rolling the lip, and the lips continues to form as the row of molds moves along the line from the point to the larger end of the brushes. This occurs while the latex is still uncured, just before it is vulcanized.

Color Issues and Packaging

Balloons are made one color at a time by adding pigment to liquid latex. Pigments are both organic and inorganic compounds that absorb certain wavelengths of visible light and reflect others. For example, a red balloon is red because the balloon absorbs all the visible light except red frequency light which is reflected back to the eye.

The strength of balloons can be affected by the pigment if the pigment particle is large in size and interferes with the film continuity and if the pigment reacts with any of the other ingredients in the balloon. As far as which color has the most effect on the balloons strength, we have not done any in depth study. Since we use pigments that are water dispersions of very, very, small particle size, and they do not react with any other ingredients in the latex, we do not detect any difference.

Pearl Tones.
Pearl tone latex is created by adding crushed mica to the latex. This process can make the latex more brittle, and less twistable. If you want to see proof of this, you have to look no further than at Tilly Pearl 130’s.
Gold/Silver/Metallic 260’s
Metallic latex is made in the same way as pearl latex.
Agate 260’s.
Agate balloons are made by dipping the mold into latex twice.
321 (Bee Body) Balloons A 321 is made by dipping just the tip of the balloon into the latex twice.

After stripping off the molds, they are counted by weight with special precision scales (different colors have slightly different weights) then packaged.

For a bag of assorted colors, a batch of equal quantities of the colors to be assorted are tumbled together, then counted (by weight) and packaged. Because of the tumbling process, there will not be an exact division of colors in each polybag. If you need a specific color, it’s best to buy a solid color bag.

The difference in price of different color ballons is due, in part, to the price of the coloring agent. Some colors are more expensive than others. The Standard Colors of 260Q (White, Pink, and Light Blue) less expensive than the Jewel Tone Colors. Solid bags of White, Pink or Light Blue are the same price as a bag of assorted.

Tim Vlamis at Qualatex writes:

Latex Packaging – We are now printing all Qualatex bags with a bar code, description, and packing date code. The date code is known as a “Julian Date Code” and reads as follows: first two digits are the year, the last three digits are the day (1-365). 96031 = January 31, 1996. In proper storage conditions (dark, cool) Qualatex balloons should last for years.

Printing on latex balloons

Printed latex balloons are inflated while the printing takes place, screen printed, then deflated, drummed in rotating industrial dryers to shrink them back to “like new,” and packaged. This is why printed latex balloons are so much more expensive than unprinted balloons. Any camera-ready artwork can be imprinted on latex balloons (as long as it does not infringe on copyright).

Balloons are printed using several different methods or types of printing depending upon the quantity, balloon size, delivery date, and other factors invloved in the order. All balloons are printed in an inflated state with the two methods described below.

The first method of printing is a form of offset printing. Ink is appled to the plate which reads right, the plate then transfers the ink to a printing drum, and the image reads wrong. The balloon is then rolled across the printing drum transferring the image to the balloon. The image once again reads right.

The second method of printing is silk screening. This method has the balloon in a flat, uninflated condition for printing. A silk screen, into which an image has been etched, is then laid over the balloon, and ink is forced through the mesh in the screen in the image area and onto the balloon. The non-image area does not permit ink to penetrate, thereby putting ink only in the image area. Silk screening is also done on inflated balloons by using a holding device and slightly compressing the surface of the printing area with the screen prior to applying the ink. This type of screening is done with an automatic machine on small to medium size balloons.

When balloons are inflated for printing, they are only inflated to approximately 75 to 80 percent of the total capacity. This gives the proper tension to the surface of the balloon for ink transfer.

Immediately upon placing the image on the balloon surface, the balloon is released and deflation begins. By the time the balloon is delfated, the ink must be dry to prevent offsetting onto other balloons.

Specialized ink must be used that will bite into the surface of the balloon and yet not go far enough below the surface to penetrate completely throughout to the interior, causing holes in the balloon.

Contrary to popular belief, balloons are not hand stamped in a deflated condition.

Printing alternative: a rubber stamp with quick-drying ink can be used to imprint on an inflated balloon.

Balloon Printing Machines and Services

There are companies that offer balloon printing services. Having balloons custom-printed is much like having T-Shirts silk-screened. The customer supplies the artwork and picks a quantity, and the company fills the order. In recent years, a few companies have introduced services for printing on 260 balloons.

There are also companies which manufacture and sell balloon printing machines to businesses.

How Foil Balloons Are Made

The concept and technology for the “metalization” of plastic sheeting that has given us foil balloons comes directly out of the NASA Space Mission. By the way, all of us should stop referring to foil balloons as Mylar (a trademarked name for a certain type of polyester film mad by DuPont) balloons. The balloon industry refers to them as “foil” balloons, because they are made of nylon sheet, coated on one side with polyethylene and metallized on the other. It’s evidently so much harder to make balloons out of aluminized Mylar (and probably so much more expensive) that nobody does it.

Polyesters are “thermosetting” polymers… ie, once formed, subsequent heating won’t melt them. Heat them enough and they just burn. For balloon workers, this means that Mylar films cannot be heat sealed. Polyethylene and nylon are “thermoplastic” polymers… ie, subsequent heating will melt them and subsequent cooling will resolidify them. For balloon workers, this means that sheets of “foil balloon material” can be heat sealed together.

The CBA videos said that since it’s so much harder to make balloons out of aluminized Mylar, nobody does it. But, if thermoplastic films can be laminated, what would stop somebody from laminating a thermoplastic film onto Mylar to make a heat sealable version? So I looked up Mylar on the web and got some current info straight from the manufacturer. Indeed, DuPont does make a variety of coated Mylars that are heat sealable (because the coating on the Mylar can melt).

The Incredible Balloon webpage says:

In the late 1970’s, silver metalized balloons were developed for the New York City Ballet. These balloons are commonly called mylar, but they are actually made from a metalized nylon and are more expensive than latex balloons. Someone wrote me that it is 48 gague (.48 mil) aluminized biaxial nylon w/ a special coating (capron emblem) for heat sealing.

Gary Felix’s company was making custom-shaped foil balloons by hand for many years. Gary designed Olympic balloons in the 1984 summer Olympics and also Jesse Ventura’s inauguration.

Making Latex Balloons at Home

The man who invented and patented the Geo, Ron Prater from Indiana, made all his prototype balloons at home, and vulcanized them in his kitchen oven (of course, his dad was a chemist at Pioneer Balloon Company…). I have a newspaper article (that was reprinted in a clown magazine) which discusses this.

Regarding making balloons at home, I’ve watched the hand dipping process and it’s a snap. One good person with a few hundred dollars invested could make a gross in about 12 to 16 hours. At that rate, the cost would be prohibitive. – Marvin

Procedure to Manufacture a Latex Dipped Item

  • Stir latex coagulent (the talc generally powder settles out). Transfer to vessle suitable for heating. Warm coagulent to 130-140 degrees Fahrenheit (warming is optional and is used mainly for fast production).
  • Warm former or form for 3 minutes at 170-175 degrees Fahrenheit.
  • Dip warm former into coagulent (coagulent should be under constant agitation).
  • Dry coagulent coated former in 170-175 degree Fahrenheit oven for 3 minutes.
  • Dip dried former in 70-75 degree Fahrenheit latex.
  • Leach latex coated former in 175-180 degree Fahrenheit water for 15 minutes.
  • Cure latex on former for 20 minutes at 200-215 degrees Fahrenheit.

MB 12/22/95
MB 12/7/96
SKB 3/9/00
MB 3/31/00
SKB 11/01/02