Chemistry of Paintballs

Who can guess what mild hypnotic medication, a cardiac drug, cough and cold preparations, stage blood, Easter egg colouring kits and PAINTBALLS all have in common? One common feature in a gelatin shell, and the other is some of the most demanding chemistry in the health, beauty and recreation industries.

You see, all of the above products are enclosed in soft elastic gelatin capsules. They are called softgels. A company called Accucaps in Windsor, Ontario has chemists working on development and improvement of these gelatin capsules for many different applications, one of which is the sport of paintball.

Now for a little history about the sport of paintball: the first use of paintballs was to mark livestock and tress for slaughter or harvest with oil-based paint. Well of course it did not take long for one yahoo to shoot another and the game of paintball was born. It turned out that many clothes were ruined due to the oil-based paint.

This new-found sport was just too good to give up, so word got back to the manufacturer of the paintballs that there was a demand for water-soluble paint for recreational use. Because gelatin (the capsule material) dissolves in water (which is water-soluble paint) this request would prove to be very challenging. The fill material would have to be water-soluble, but containing no water, and it would need to be capable of carrying dyes or pigments, but non-staining and thick enough to not run off its target. Furthermore, it needed to be compatible with the gelatin capsule. The formulators in this case were the Production Chemists, Quality Control Manager, and Quality Control/Product Development Chemist. These were the people who knew the most about what could or could not work for this project.

After making a compatible fill material the chemist knew that the gelatin shell of the paintball would require special attention, too. The gelatin shell had to withstand the sudden acceleration from zero to 90 metres per second in a span of 35 centimeters then hit a relatively soft body at 30 metres and break. So, the shell had to be strong yet brittle. After adjusting the plasticizer-to-gelatin ration, a more brittle shell was accomplished. Secondly, using gelatin derived from pig skins (rather than the usual source, connective tissue of cows) made for much better paintballs.

At one point all the paintballs in the world were being produced in Windsor, Ontario because this is where the sport of Painball as we know it today was invented. That was eleven years ago and billions of paintballs have been produced. The paintball fad is still growing and Accucaps in Windsor, Ontario is now concentrating on softgels in the cosmetic industry…but that may be another story in itself.