While Tivo-surfing for new material, I came across “How It’s Made,” focusing on the mechanical steps involved in producing a particular kind of widget. It’s much lighter than Mythbusters and Dirty Jobs, but still entertaining. Because the show has been around a while, my Tivo picked up a dozen showings before I told it to knock it off.
The episode I watched last night showed how Rose Art’s crayons were made (slightly different than Crayola’s recipe.) Some snippets:
- The crayon base is made from a combination of waxes, primary paraffin because it’s cheap, and has a nice “rub-off”
- Wax is melted at 144°F. They add a “secret powder” as a filler and to provide some structural strength. They also add various fatty acids ( e.g, stearic acid) to prevent the goo from sticking to the machinery. Stearic acid also enhances the rub-off. Every ingredient is non-toxic.
- Once dye is added, it blends for 45 minutes. The factory shown can make 127 different colors. The most popular packages are 16- and 24-packs.
- Wax is pumped into rotary machine, then injected into crayon-shaped molds. Water is added to cool (and thus harden) the wax. Excess is scraped off and recycled. Each machine can do 2,700 crayons per cycle.
- With several machines, they make 30,000 per hour.
- When set, the crayons are ejected from the mold and transported on a conveyor.
- A gluer coats surface between grooves. A labeler wraps the strip of paper around the crayon. It can do 8,500 crayons per hour.
- Crayons land in bulk box, where they’re sorted by workers to packaging hoppers
- Broken crayons or loose labels will cause the machine to stop until workers fix the problem.
- Crayons slide into a box and are weighed. If a box is underweight, it’s kicked out of the line and manually filled with the missing crayon