What is Hot Melt Gravure Lamination?
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.
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.