Plastic Hinge Material?

Hi,

Wondering if anyone can point me in a good direction…

I’m looking for a thin plastic (maybe a film?) that I can use as a hinge to join two pieces of 1/8" acrylic. This hinge needs to bend in order to create the shape I’m making , but it will not be used as a hinge per se (ie, no repeated bending).

A few more requirements:

I’d like the material to be clear or translucent (not white)
I’d like to be able to “glue” it to the acrylic with solvent (ie, a permanent bond)
I’d like for it to have little or no memory.

I guess I’d like it to function sort of like tape, only I’d bond it to the material.

Any ideas?

Many thanks!

Julie

… sounds like acetate, or mylar (although mylar can be tough to bond).

I’m curious julie, you didn’t mention how much it needed to bend ( 30°,45°, 90° (?) )

Hi Lew,

90 degrees will cover it, although the angles will likely be a little less. I would like for the material to have little or no memory, and no radius at the bend. Kind of like packing tape…hmmm, maybe some kind of vinyl? Just need to get a good bond…

Thanks!

If you use polycarbonate, you might be able to use the material itself as a hinge. It can be bent similar to sheet metal.

Hi Julie,

You could use acrylic in a paper-thin thickness which would simplify the bonding (like materials bond easiest) but unless you’re talking about arc’ing the material 90 degrees (a soft radius) then acrylic, acetate, mylar and the like will all take a shape if creased.

If creasing (a sharp 90 degree corner) is the goal and if the big-picture affords a molded part, then polypropylene might be a good answer since the part can be designed with a living hinge that can crease or radius once or any number of times and will do so across a much broader temperature range than the other potential materials.

Define bond.

If you mean molecular, acrylic will only bond to acrylic. Makes for a horrible hinge material.

If you mean adhesive force (van der Waals, electostatic, hydrogen bonding, etc), any clear adhesive laminated to a clear film would do the trick. Packing tape would be an option.

Yes, molecular with acrylic adhesive. I indicated that a radiused bend would be the only suitable result as any sharp crease would damage the acrylic quickly. :wink:

Thanks everyone. I should probably mention that this is for a prototype I’m building myself.

I’ve researched polycarbonate a bit and it seems like it could be a good an option. It can be cold bent at thicknesses <.1", and methylene chloride will create a molecular bond. I might be able to do away with the acrylic entirely and just use the polycarbonate, if it’s stiff enough and can be bent too.

Time to get some material and try it!

I appreciate your help, and I’ll report back on the results.

Best,
Julie

Using any solvent, for acrylic, PC, ABS or whatever, to bond is a tricky process. It is impossible to get an even coat which will lead to kind of a bubbling effect that is very visible with clear materials. The materials are also not truly flat, which doesn’t help. You can kind of overcome this by using a press, but sometimes no matter what you do it comes out crappy.

Please do not start with your final part. Do a lot a practice parts first.

Also, use great ventilation with those solvents and wear rubber gloves.