Everything begins with the adhesive. As a rule, we produce this ourselves. In the case of acrylate substances, this means that we begin with the polymerization. In other words, the components of adhesives, the molecule chains or the polymers, are mixed with each other in a chemical process. Subsequently, these adhesives are prepared so that we can apply them easily and very thinly to the desired backing material. How this takes place depends on the adhesive.
During production, some adhesives are transferred with an organic solvent that vaporizes very easily. It is exactly this that we use to our benefit: the adhesive is applied very thinly to the backing with the solvent by pressing it through a very narrow slit. Then the coated backing passes through a drying tunnel and the solvent evaporates in it. The adhesive tape coating becomes solid and is connected firmly with the backing after the drying process. The evaporating solvent is almost entirely recaptured at tesa and fed back into adhesive production.
The operation is similar with water-based adhesives. Simple water is added as the solvent for these and then escapes in the drying oven as steam. A process that is widespread at tesa.
In a third process, the 'hot melt' adhesive is produced. Here the adhesive turns liquid by heating it and is mixed in an extruder, a kind of meat grinder. This adhesive is also then applied evenly to the backing through a very thin slit.