Hot Melt gravure or “Dot” lamination uses an exact pattern of microscopic “dots” of adhesive on the surface of one web of material to bond that web to another web of material and form a composite. For this reason, Hot Melt Gravure Lamination is also known as "Dot" Lamination. The materials joined can be the same material or entirely different types of materials, such as nonwovens, films, fabrics, or already made composites.
This is called a gravure process because it is similar to the rotogravure printing process. In rotogravure, pictures, designs and words are engraved into the printing cylinder. The cylinder picks up ink as it rotates and deposits the ink on the paper web (for example) as the paper passes against the cylinder.
In the Hot Melt Gravure process, adhesive is in a heated trough until the right viscosity. As the rotating gravure roll contacts the trough, the cavities on the roll are filled with adhesive. A doctor blade seals the trough towards the engraved roll and cleans the surface of the latter, so that adhesive is only applied in the pattern of the engraving to the receiving web as it passes.
As the web passes between the gravure roll and a counter roll. The receiving web then contacts the mating web under appropriate temperature and pressure to form the composite.
It is extremely important to realize that this is a very precise process. The amount of adhesive deposited for each "dot" is very specific depending on the pattern roll used, the type of the adhesive, the temperature of the adhesive, and the material onto which the adhesive is deposited.