I second the suggestion for gorilla glue. This seems like the perfect
application for a foaming polyurethane glue

For a dispenser take a look at;

http://www.efd-inc.com/index.html

They are not particularly cheap (I got mine at a junk shop for $25),
but I can attest to the fact that they are slicker than snot. They
use a pulse of air pressure to dispense a discrete amount from a
syringe and then a slight vacuum to keep the syringe from drooling.

Labor is going to be the killer though. It would be simplest to apply
the glue before the bristles are inserted, but that would drag glue
all over the inserting machine.

Even with the the dispenser, using a single tip, I can't see you
getting the time below 90 sec each.

Using multiple tips and/or semi automating it seems the only way to go

Paul K. Dickman

On Thu, 20 Jan 2005 14:02:17 GMT, "Tom Gardner"
wrote:

I have a situation that I need help with. I have a big bunch (3k) of
brushes that need better tuft retention for a special application. The
brushes are 7" long x 3-1/2" wide and have 50 holes/tufts in them. Each
hole is 1/2" deep x 9/32" dia. and each tuft is 3 flat wires bent 180 deg,
and stapled into the hole with a 18 ga., 1/4" crown x 1/2" leg staple. I am
thinking of injecting glue of some kind into the hole with the wire. These
brushes are already made. If I can inject glue or epoxy into the holes, the
material will have to be able to withstand the brushing action and not
crumble or pop out. I wonder if carpenter's glue would work. I'm looking
for leads for some type of powered dispenser too. My budget needs to be
under a buck apiece including labor.

Apparently, the action of the brush in this application is way different
than normal. They use the brushes in a linear motion that is parallel to
the staples. They use the sides of the flat wire to break spoo up rather
than the face of the flat wire to "sweep" like a normal use. This action
has a tendency to rock the staples out even though the tuft retention is
over 40 pounds pull-out strength. (Where's that Unabtaniun when I need it!)