Adhesive application to a small cylindar

Maybe 'print' it on?

Using something like a pad printing machine? Dunno if you would get it inside the lip....or just on the end face (assuming it would press on to the end).

How about apply it to the other component?

How about having the dispenser orbit the stationary cylinder?

Or perhaps a collet to hold and rotate the cylinder. The tire and V-block sounds like a lot of slippage and resulting non-uniformity of adhesive application.

A peristaltic pump would probably give greater precision in the amount of adhesive applied.

Nothing tried, nothing gained!

Dick

I agree with Del, a form of stamping might be simpler whereyour cylinder stamps a pad through a hole, the outer lip pressing the glue into the recess as th e cylinder bottoms out. A small turning action at the end will even out the spread. glue would be supplied through a tiny gap between non-stick pad and the sheet the hole is in.

Alternatively fit your current machine to automaticaly self adjust. More even spreading of the different batches of glue can be achieved by using a mechanical pump, as these are not affected by product consistency ie x movement produces x output. whereas pneumatic methods match pressure to viscocity varying the flow rate depending on product (viscoscity). A mechanical pump also allows you to lock glue flow to machine speed precisely

How about buying solid adhesive preforms, perhaps frozen. That way you could place an exactly known volume of adhesive each time instead of trying to regulate the flow of a viscous material by gas pressure.

Yes, pad printing is a good suggestion. I have written an article on pad printing for non-marking solutions at:

http://www.padprintmachinery.com/InTheNews.cfm?id=24

Here is another alternative:

Mask the cylinder by insertion into a thin-wall cylinder or tube, re-formulate your adhesive with more solvent and use a sprayer to evenly coat the area. The spray may eliminate problems with the beginning and end of a bead, where the bead may be too thick or too thin because of acceleration/deceleration or other problem with timing. You may want to do this vertically instead of horizontally to avoid gravity problems. Surface tension should hold the adhesive fluid in place even if a substantial "bead" is created this way.

You may use either a point sprayer and revolve the part or the sprayer tip, or use a ring sprayer for even distribution without motion. If you are concerned with overspray or underspray at the beginning or end, make the sprayer activate first, index the tip into position and retract off the workpiece before stopping the spray. With proper adjustment there should be very little waste.

Consider also whether the UV cure adhesive is the best solution. Not knowing the rest of the application it is difficult to say what would work but other possibilities include:

- application of adhesive powder similar to "hot melt" but with specifications which suit your process. Adhesive is then activated by heat to adhere to the aluminum and later to the joining part, either by conduction of the parts, IR radiation, or by convection in an "oven" (which can be nothing more than an insulated box with a few heaters inside)

- dispensing a hot melt "bead". Alternatively, the "beads" may be pre-made as rings and assembled in place then activated by heat and cooled quickly with air after setting up. Some pressure on the mating parts would need to be applied, possibly by a light spring in the assembly fixture. Excess material,if it exists, may be easily removed, just by "plucking" or other simple mechanical action, often simply by an inspector who would handle the parts anyway.

- epoxy with a relatively long cure time can also be dispensed, then the cure can be speeded by application of heat.

- Silicone-based adhesives may also be applied by above methods and cure with heat and/or humidity. May be ideal for some work environments! <grin>

I feel, you can use special dispenser nozzle with multiple dispensing at a time along the periphery of the cylinder from inside. Metered quantity can be dosaged at a time and distribution will also be equal. More the number of holes in the dispenser, better will be the distribution of addhesive. Hope to get you right solution. Bye.

Sounds kind of similar to:

"...use a ring sprayer for even distribution without motion." from my posting above. Substitute the word "dispenser" for "sprayer" and "peripheral" for "ring" (basically the same thing), and there is not much difference.

OK, I did not put it together with the viscous liquid instead of the less viscous "spray", but you could at least give me some credit for suggesting the stationary dispensing!

Yes... u r right STL, i will share only 40% of royalty and remaining you, if the originator of this thread uses our idea.... Anyway, putting all together and adding some more, the right words of our proposal could be - " Staitanory ring type dispenser with single jet multiple nozzles positioned for metered quantity dispensing along the inside periphery of the cylinder " ..... No..? Cheers.

Hello all,

Thank you for all your ideas! We cannot spray because the cylinder has an optic installed on the opposite end. Orbiting the dispenser is more complicated then what we have designed and we still need to rotate the cylinder to initial conditions because of defects in the optic. I am looking into stamp application and I like the idea of "multiple holes in a ring configured dispenser" but it would clog and cause problems due to the higher viscosity of the UV adhesive we use. (Although I should run an experiment to see if this is true. This one we will have to think through abit more.

Such is life on the cutting edge!

Paul