There are three basic processes used in the packaging
industry for applying wax: coating, laminating, and impregnating.
The coating process lays wax ON the surface of a packaging
material. Laminating applies wax BETWEEN two materials.
Impregnating causes wax to be driven INTO a packaging material
surface.
These processes may be used independently or in combination
- but wax is almost always applied in a molten state. To
attain the properties that wax can produce, packaging materials
are usually coated, laminated, or impregnated with a continuous
film of wax using one or more of these basic application
methods:
1) Rolling (Roll Coating). The material is waxed by
passing over or under a roller that has a layer of molten
wax on it. The rollers "kisses" the material
and thereby transfer the wax to the materials surface.
The rollers may be made of metal, rubber, or other materials
and can be smooth, patterned or felt covered.
2) Dipping (Impregnating). The material is dipped or
submerged into a bath of molten wax.
3) Passing (Curtain Coating). The material is passed
through a curtain of falling wax.
4) Flushing (Cascading or Saturating). Wax is flushed
into or over the material.
5) Spraying: The material is sprayed with molten or
powdered wax.
These five basic methods can lead to many variations,
and an otherwise simple machine or process can become quite
complex. Our SouthWest Wax Sales and Technical Team are
available for consultation and assistance in using these
procedures.
The coating process may use paraffin, microcrystalline,
or a blend. Laminating makes use of microcrystalline wax
due to the need for superior adhesive strength,
cohesive strength and flexibility. Impregnating primarily
uses paraffin. Selecting the right wax is based not only
on the waxes property, but also the results desired, the
materials to be processed, and the machines used for application.
The degree to which the wax is applied ON or INTO (or
some combination of the two) the material is also determined
by the physical characteristics of the wax and the packaging
material being treated. This is controlled by the speed,
temperature, pressure and time used during the application
process. Recognizing and knowing how to control these factors
will simplify and/or eliminate most wax problems.
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