-1
$\begingroup$

There are keys (push buttons) on the front panel of an avionics device that fits inside the aircraft cockpit. I need to know the material of which those key-tops are made from.

enter image description here

I can guess the material is some type of clear transparent plastic and then its painted with black color. The text on it is un-painted key surface. There is green light under the keys (buttons). That green light glows the text (due to transparent plastic) on the key-top as green in color.

This cockpit device is from a very old aircraft model of 1950's so we can say it is not using any modern high performance thermoplastic or composite material. How can I best identify the material of these key-tops?

Do i need to delete this post from here as now I have posted it here also?

Improve this question
$\endgroup$
3
  • 1
    $\begingroup$ This question will fare better in the Aviation StackExchange. $\endgroup$
    – kamran
    Sep 15, 2020 at 7:45
  • $\begingroup$ Seems unlikely to be painted - more likely a two-shot moulding. Paint would have shown signs of wear in 70 years! $\endgroup$
    – Jonathan R Swift
    Sep 15, 2020 at 11:24
  • $\begingroup$ Do you have a sample of material that you are able to destroy? There’s processes for determining what plastic something is, but it usually involves burning to observe the flame and smell! $\endgroup$
    – Jonathan R Swift
    Sep 16, 2020 at 7:18

1 Answer 1

Reset to default
1
$\begingroup$

Have you heard of double shot moulding? In this process, the white is a separate molding that is actually embedded behind the black key. This would not show wear and might narrow down your material choices. Nowadays this is done with ABS or PBT. I don't know about your application though.

Improve this answer
$\endgroup$
4
  • $\begingroup$ A common example of double-shot moulding you'll be familiar with is soft-grip toothbrush handles. $\endgroup$
    – Transistor
    Sep 15, 2020 at 21:38
  • $\begingroup$ @DKNguyen I need to glow the text on button using the LED light that is situated under the button body. How will the double-shot molding work in this case? Do you mean the white color text on the button-top will be the second-material used in the injection on top of the base black button body material? $\endgroup$
    – scico111
    Sep 17, 2020 at 10:01
  • $\begingroup$ @scico111 Two materials, but the white frame is actually an insert that enters from underneath. Google double shot button images. $\endgroup$
    – DKNguyen
    Sep 17, 2020 at 13:28
  • $\begingroup$ encrypted-tbn0.gstatic.com/… $\endgroup$
    – DKNguyen
    Sep 17, 2020 at 13:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.