Joining mixed material extrusion

[Elastomatt]

Hi All,

Back seeking some advice regarding joining a mixed material extrusion. The profile is basically a boot/door seal design with a sponge bulb on a plastic (so our lab tells me) covered metal carrier.

We have had some issue with the joining of this process, the customer has requested the parts to be glued rather than joined with Normec film. The profile is more are than material (bulb is only 2mm thick and the carrier is about 2mm with 4 small limbs to retain profile in situ).

Initial problems were caused by the cutting process crushing the carrier part of the profile. On review we identified the optimum position to cut (between the metal carrier). The current issue relates to splits at the joint, we are using Loctite 424 as an adhesive.

Any advice on the best way to cut/join these? I would like to go down the Normec route but believe we will need lower temperatures and longer cure times than we do for our dense rubber profiles.

Our Normecs are single head machines, however I have seen a carousel of neads used to good effect in the past.

Thanks

 

[btrueblood]

I assume you are using a shear to cut, and the parts are splitting (adhesive failing) near the cut line. Have you tried an abrasive cut-off wheel?

Hmm, after googling the brand name, it looks like they offer a diamond (abrasive) cutting wheel in addition to a guillotine/knife shear. Which are you using?

Loctite fails beautifully (easily) in shear (we used to use it to attach accelerometers to vibration test units, as you could remove the accel block with a sharp sideways rap with a wooden dowel), and may not be a good choice for this bonding. Something like a 3M acrylic tape might be a better choice (it's a more malleable/flexible adhesive), but it sounds like your customer doesn't like this for some reason?