A white paper - Manifold Assemblies 9
Laser bonding
The method IMI Precision Engineering
prefers to use when building its acrylic
manifolds is laser bonding. Once the
pieces of the manifold are machined and
cleaned, a laser absorber is applied. A
laser is passed over the part for a few
seconds and the light wave interacts with
the absorber to generate heat in a very
focused area. This acts as a "flash weld,"
bonding the pieces together. The absorber
discolors the plastic slightly, leaving a
visible clue as to where the joint was, but
the material itself is burnt out by the laser,
leaving no residue in the manifold channels.
Since with laser bonding the manifold is
exposed to heat over a very small area for
a very short time, the features machined
into the plastic retain their original shape.
Laser bonding results in very stable
dimensional accuracy and integrity.
Thermal diffusion bonding
The science behind this method is that
pressing two things together with enough
pressure, heat and time will eventually
cause the molecules of each to fuse into
one. This results in a solid block of plastic
with no weak spots. Pressure and heat
over time can distort the shape of the
channels, so it important that the pieces
are machined precisely to compensate
for this. The labor required to accomplish
this and the time the piece must be under
pressure combine to make this a fairly
time consuming and costly process.
