Developing a product/how it's made

[LiftAndShoot]

Hey guys -

Bit of a random question (ok it's super left-field territory), but I'm hoping there are some engineering/knowledgeable types out there that can point me in the right direction.

You've been forewarned.

So, the question: If anyone owns a pair of nice sunglasses (like Costa Del Mar, Kaenon, Smith, etc.) you know that they come with a hard case. It feels like molded plastic covered in a fabric material. Does anyone know: a) what the kind of material under the fabric is and b) how that fabric is meshed with the case?

To help lower the eyebrows of those that might have read that, I'm trying to put together a product prototype that has a similar structure to this kind of thing - just don't know what they are made of and/or how to source the material.

Thanks!
-LaS

[Trust]

I got an old Oakley case and work in Arlington if you want it for research.

[Puggy625]

Most are some form of molded polypropylene, some are possible some type of "cardboard" mold. The cloth would most likely be applied with some sort of vacuum system to get it to form to the case.

[Hawkpuppy 1]

I would assume a thermo molded plastic that is probably sprayed with a high strength adhesive and then wrapped in what ever fabric you would like.

[LiftAndShoot]

I would imagine, then, that there's some kind of custom made mold and then plastic/poly is heat formed around the mold? That sound right?

I bet having a custom mold made for something is profoundly expensive..

[Texas Grown]

You could probable make one with Kydex as well.

[LiftAndShoot]

You could probable make one with Kydex as well.

Oh I didn't even think of that. Thanks.

[Texas Grown]

Oh I didn't even think of that. Thanks.

Just send me %5 of the royalties.

Good luck on your adventure.

[texaspyro21]

Was going to recommend kydex as well. You can make a press with plywood, something to act as a hinge and foam padding. Probably under $100 with a nice heat gun without trying.

You could also make a vacuum mold to do the fabric. I made one in high school to create 6inch thick plywood using thick plastic and a vacuum pump from harbor freight.

[AZST_bowhunter]

I would imagine, then, that there's some kind of custom made mold and then plastic/poly is heat formed around the mold? That sound right?

I bet having a custom mold made for something is profoundly expensive..

2 things that may help you..

1. Find someone that has access to CAD and is good at using it, have them draw up what you are trying to do..

2. Find someone with a 3D printer and print a prototype of your mold.

I would guess that the cases are made of polypropylene (like mentioned above), the problem you may run into is the poly sticking to the cast/mold you make. Good luck!

[GrapeApe]

Custom molds aren't terribly expensive for something that simple.

Any yahoo with a CNC mill can run you one out of tool steel and you can send it to be heat treated.

There are a few considerations but most modern CAD can cover them.

If you're just looking to make a few, aluminum would work just fine.

[coachwhip]

As a kid I worked at Nokona Athletic Goods, we built hip pads that had fabric glued to a closed cell foam (volara), next pieces were heated in an oven and then pressed with a pneumatic press into a mold. That piece was then trimmed to the final shape The key is keeping the temperature just below the melting point of the foam. Could be done pretty easy with a heat gun, mold, and hydraulic press if you have the correct closed sell foam.
Hope this helps