moogull
Mechanical
- Oct 28, 2012
- 2
Hello Eng-tips, first time posting here.
I'm working on a thesis project and I need some advice on adhesives to use for bonding laser sintered Nylon 11 to Butyl Rubber (scavenged from an inner tube). The Nylon part is two buckled beams extruded out (they are pre-formed but have the same buckled shape as a fixed/fixed buckled beam) and they form a tube. The Butyl is intended to form an elastomeric seal over the ends of the buckled beam tube. The beams are going to "snap through" transversely (think of taking a playing card and buckling it then pushing it through the center from one stable position to the other), so the bond between the elastomer and the nylon structure must be flexible and must not embrittle either of the substrates. Functioning as intended, the cavity will push and pull a vacuum when the beams snap through and snap back.
I have tested a two part polyurethane adhesive (Called "Double/Bubble" A-85 from Hardman) and a cheap super glue (ethyl cyanoacrylate) on a Butyl and Nylon sample. I did rough up each surface and clean with a solvent. The polyurethane seems to have a pretty low peel strength (I could peel it off easily), but a decent shear strength, which I think is more important in this application. The super glue seems to perform better in both these aspects.
I have talked with some folks at Henkel and got all kinds of different ideas, but it looks like a cyanoacrylate is what is recommended. I would appreciate any input on the best adhesive to use in this application.
One more note, the reason I have chosen Butyl as the elastomer is because it seems to be the most impermeable material (to air) that is relatively cheap. However, permeability really isn't a huge deal because I'm not trying to hold a vacuum for hours and hours. I'm only trying to push and pull air whenever the tube is compressed. With that in mind, I may be able to use a different elastomer that is more friendly to adhesives.
Thanks!
I'm working on a thesis project and I need some advice on adhesives to use for bonding laser sintered Nylon 11 to Butyl Rubber (scavenged from an inner tube). The Nylon part is two buckled beams extruded out (they are pre-formed but have the same buckled shape as a fixed/fixed buckled beam) and they form a tube. The Butyl is intended to form an elastomeric seal over the ends of the buckled beam tube. The beams are going to "snap through" transversely (think of taking a playing card and buckling it then pushing it through the center from one stable position to the other), so the bond between the elastomer and the nylon structure must be flexible and must not embrittle either of the substrates. Functioning as intended, the cavity will push and pull a vacuum when the beams snap through and snap back.
I have tested a two part polyurethane adhesive (Called "Double/Bubble" A-85 from Hardman) and a cheap super glue (ethyl cyanoacrylate) on a Butyl and Nylon sample. I did rough up each surface and clean with a solvent. The polyurethane seems to have a pretty low peel strength (I could peel it off easily), but a decent shear strength, which I think is more important in this application. The super glue seems to perform better in both these aspects.
I have talked with some folks at Henkel and got all kinds of different ideas, but it looks like a cyanoacrylate is what is recommended. I would appreciate any input on the best adhesive to use in this application.
One more note, the reason I have chosen Butyl as the elastomer is because it seems to be the most impermeable material (to air) that is relatively cheap. However, permeability really isn't a huge deal because I'm not trying to hold a vacuum for hours and hours. I'm only trying to push and pull air whenever the tube is compressed. With that in mind, I may be able to use a different elastomer that is more friendly to adhesives.
Thanks!