The first toothpaste tubes were made of tin and lead and remained so until there was a metal shortage during World War II. During the war, tin and lead was reserved for the military and production on toothpaste turned to aluminum and plastic. Though, it was found that some of the ingredients in the toothpaste reacted poorly when it was exposed to aluminum. By the 1990’s, all-plastic toothpaste tubes replaced the aluminum containers and have been thriving ever since in industries such as cosmetics, oral care and food.
Creating the plastic tube that contains the toothpaste is all about heating and molding. The process is called extrusion and it takes small plastic particles like pebbles and powder and turns it into molten plastic resin. The resin is forced into the barrel of an extruder through a die which is a thick steel disk that acts as the mold for the tubes. In the barrel is a large screw that rotates the plastic materials and facilitates the heating and melting of the resin. The plastic is melted gradually by the energy generated from multiple heater zones before it’s goes through a screen pack to remove any contaminants that remain. The plastic is then forced through to the mold (die) where it can take up a collapsible shape of its own.
Then comes the cooling process where the plastic undergoes a water bath where it cools and hardens. To keep the tubes from collapsing before they have the chance to harden, the water bath is started by a controlled vacuum so that the plastic can keep its profile and doesn’t warp. The plastic tubes are then able to keep their shapes and designs after each squeeze because of their physical memory/mold. The tubes are then decorated and designed by methods such as silk screen printing and flexographic printing. After the tubes are then moved to a separate facility to be filled with the product they’ll hold on the shelves.
For plastic toothpaste tubes, the toothpaste is weighed and mixed in the mixing vat using the glycerin-water mixture method while the level of heat and humidity are watched closely. The mixing vat is sometimes capable of mixing batches that are equivalent to 10,000 four-ounce tubes. Before the toothpaste goes inside the tubes, the tubes pass through a blower and vacuum ensuring that all dust and particles are blown out and that they are clean, sanitized and ready to use. The chosen cap is then put on and the paste is loaded into the tubes on the opposite sides using a filling machine that consistently rotates, filling the tubes evenly. The end is then sealed or crimped and the tubes get a code stamped on them indicating when and where theywere made. Once this process is done, it’s time to pack the tubes and ship them off.