How are Latex balloons made today?

Pure Latex, in its natural form, is milky white in colour. It usually arrives in North America from rubber producing countries via large ocean going tanker ships. It is then either shipped by rail or trucked to the balloon manufacturer. To make it suitable for balloon production, various curing agents along with accelerators, oil, colour, and water must first be added to the mix. After these elements are added, the prepared Latex is placed into a wide, open-topped tank that is located immediately beside the balloon production line.
Almost all commercially produced Latex balloons are now manufactured by dipping metal balloon forms (in the same shape and size of the uninflated balloon it will help produce) into these tanks of liquid Latex. For example, a balloon form for a round balloon is shaped like small light bulb. However, before the forms can be dipped into the liquid Latex, they must first be dipped into a coagulant that causes the rubber particles of the Latex to collect on the form. This coagulant is calcium nitrate, water, and/or alcohol. After the coagulant coated form is dried, the actual process of balloon making can commence.
In the next part of the process (most of which is automated these days) the variously shaped balloon forms are dipped "upside down" into the open-topped Latex tank at the proper point in the production process. For example, to make a round balloon, the form is dipped bulbous (top) end first. Because it is dipped "upside down", the excess Latex has a tendency to drip off the "top" of the form, making that part of the balloon just a little bit thicker than the bottom. This forms what is called a "drip tip" on that end. These are the little dark spots of thicker Latex you often see in the top center (or ends) of most inflated Latex balloons. It also follows that because the Latex at the top of the balloon is usually the thickest, the thinnest (and therefore the weakest) part of the balloon will usually be near its neck.
After dipping, the Latex coated forms are turned right side up again and are then passed through a set of revolving brushes that roll the balloon necks into the familiar looking beads or lips that aid in the inflation of the balloon (these beads are called "nubbins" in the balloon industry). In this part of the process, the excess (ragged) Latex at the bottom of the neck end of the balloon mold is rolled upwards (toward the bulbous or wide end of the balloon) by small motorized brushes. The brushes are positioned horizontally (one on each side of each row of molds) and are mounted so as to "point" toward the approaching molds. As the rows of Latex-coated molds progress down the production line, they pass between the rotating, cone shaped brushes. The brushes turn in opposite directions and lightly touch the molds at the neck (bottom) end, thus rolling the Latex into the familiar nubbin shape on each newly formed balloon. This process all occurs while the Latex is still uncured.
Now, the almost-completed balloon, still on its form, is washed in hot water to remove any unused nitrate. Following this process (called "leaching"), the balloon-covered forms are then put into an oven at 200-220 degrees Fahrenheit (in a process called "vulcanizing") to cure for 20-25 minutes. Once cured, the completed balloons are removed from their forms (stripped) and sorted for later imprinting or prepared directly for packaging and shipping. The metal forms are saved for later use and can be re-used over and over again in future production runs.
A fully automated balloon factory (running multiple (automated) production lines) can produce upwards of one million Latex balloons per day this way!