Fluorides reduce decay by increasing the strength of teeth. Sodium fluoride is the most commonly used fluoride. Sodium perborate is used as a tooth whitening ingredient. Most toothpastes contain the preservative p-hydrozybenzoate. Water is also used for dilution purposes.
The Manufacturing Process
Weighing and mixing
• 1 After transporting the raw materials into the factory, the ingredients are both manually and mechanically weighed. This ensures accuracy in the ingredients' proportions. Then the ingredients are mixed together. Usually, the glycerin-water mixture is done first.
• 2 All the ingredients are mixed together in the mixing vat. The temperature and humidity of vat are watched closely. This is important to ensuring that the mix comes together correctly. A commonly used vat in the toothpaste industry mixes a batch that is the equivalent of 10,000 four-ounce (118 ml) tubes.
Filling the tubes
• 3 Before tubes are filled with toothpaste, the tube itself passes under a blower and a vacuum to ensure cleanliness. Dust and particles are blown out in this step. The tube is capped, and the opposite end is opened so the filling machine can load the paste.
• 4 After the ingredients are mixed together, the tubes are filled by the filling machine. To make sure the tube is aligned correctly, an optical device rotates the tube. Then the tube is filled by a descending pump. After it is filled, the end is sealed (or crimped) closed. The tube also gets a code stamped on it indicating where and when it was manufactured.
Packaging and shipment
• 5 After tubes are filled, they are inserted into open paperboard boxes. Some companies do this by hand.
• 6 The boxes are cased and shipped to warehouses and stores.
Quality Control
Each batch of ingredients is tested for quality as it is brought into the factory. The testing lab also checks samples of final