Thermoformed Petg/pmma Part

[Guest Dastardly_Dave]

Hi guys,

I'm currently designing a part that will most likely be thermoformed....vacuum formed to achieve the desired geometry.

The part has a depth of draw ration of 3:1 which is quite large but unavoidable as this is an accessory to an existing product.

 

The next issue is that I need to use PETG or PMMA or another optical grade of material with high light transmission that can be formed easily. The reason for this is it is going in front of a camera lens.

I think the PETG will perform adequately for the deep draw, but I am concerned about it's optical properties. Also the part needs to collapse, I'm going to do some tests on thurs/fri with some 1mm Vivak (PETG Sheet) and am hoping that the deep draw will create a section thickness amenable to collapsing without compromising the part.

 

I'm wondering has anybody worked on a similar project or has exp with thermoforming? Also could I be overlooking a suitable material. Any suggestions or experiences would be appreciated.

Thanks for your time and hopefully your input

Regards

Dave

[Guest miuse]

in my experience i found that PETG has a slight "green" coloring. if optics are not critical then its probably ok, else PMMA.

having said that, PETG is a little more "elastic" / PMMA quite hard and will shatter or crack.

 

how big is the part / height of draw? you mention 1mm thickness

what is the estimated impact force required to collapse the part?

when you say "collapse" does this mean allow for splitting, breaking or cracking? or folding in on itself? (see my earlier comment about material)