I saw an old pair of computer speakers the other day and they were the old-school basic beige plastic from 20+ years ago before around 2000 when black and gray and silver etc became all the rage.

They were this nasty yellowish shade, and I know they weren't like that new. Does this type of plastic degrade over time and that's some sort of patina like a rust on metal?

Just wondering.

Back in the day smoking in the office was allowed, so most plastics picked up those colors from the second hand smoke in the office...

We had an office fire above a drop down ceiling, the metal bars were not hurt but several of the panels had to be replaced, it looked like smokers Tic Tac Toe after with the while squares against the yellowed metal strapping

OK science...

The link of truth

Of course, UV radiation isn't the only factor that can cause plastics and polymers to age. Exposure to visible light, extreme temperatures, humidity or exposure to solvents can also cause a polymer to fail over time. When it comes to yellowing, however, UV light is often the primary culprit.

My guess is that they used dyes, or some not so lightfast pigments like you’ll find in use today.

quote:

Why Does Beige (Computer) Plastic Get Nasty Yellow Over Time?

UV?

My keyboard is an IBM M2 with a born on date of 09 Oct 1989 and it's still ivory. (Yup a clicky!)

So my guess is "cheap plastics".

ABS plastic yellows. The old model m’s use dyed PVC(?).

I have a ‘91 “clicky” M that’s really clean.

Too much porn?

Not enough porn?

^^^^^
(Dusty78 and RAMIUS)

Id guess UV lighting does a lot of the damage over time.

I don't smoke and I've had beige computer plastic turn yellow brownish over time.

I had always heard that the fire retardant in the plastic cause it to yellow over time. But it is probably due to UV (or the combo).

Found this explanation at Hack-a-Day

I worked at Texas Instruments and our Printers and Monitors turned yellow under UV light. We solved the problem by adding Titanium Dioxide (TiO2) to the mix.

Polymers can be classified in a number of ways, one of which is either aliphatic or aromatic. Aliphatic polymers, acrylic for example, tend not to yellow over time and give off a colorless/white smoke when burned. Aromatic polymers, such as polystyrene (used in ABS plastic) yellow when exposed to UV light sources and produce a black, sooty smoke when burned. As pointed out by others, pigments can be added to reduce yellowing as well as UV absorbing compounds that act as a 'sun screen' for the polymers...sorry, I could nerd this out for a while.

Michael

quote:

Originally posted by mdblanton:
Polymers can be classified in a number of ways, one of which is either aliphatic or aromatic. Aliphatic polymers, acrylic for example, tend not to yellow over time and give off a colorless/white smoke when burned. Aromatic polymers, such as polystyrene (used in ABS plastic) yellow when exposed to UV light sources and produce a black, sooty smoke when burned. As pointed out by others, pigments can be added to reduce yellowing as well as UV absorbing compounds that act as a 'sun screen' for the polymers...sorry, I could nerd this out for a while.

Michael

Will our polymer handguns (Glock, H&K, M&P 2.0, etc.) have an issue, like 20 to 30 years from now where they change color and become brittle or otherwise change for the worse, like the old computer plastics?

I always associated it with heat exposure (a LOT of beige stuff wound up in garages). But I'd bet UV is pretty huge and the two together seem to produce a harvest gold in old beige computer stuff.

quote:

Originally posted by radioman:
Will our polymer handguns (Glock, H&K, M&P 2.0, etc.) have an issue, like 20 to 30 years from now where they change color and become brittle or otherwise change for the worse, like the old computer plastics?

Keep in mind that polymers have been used in gun receivers/frames for quite a few decades. There are 60 year old Remington Nylon 66 rifles with polymer receivers, and 49 year old HK VP70s with polymer frames, and those still work just fine.

I have a 30 year old Glock 19 (made in 1989) whose polymer frame is still as good as the day it was made.

quote:

Originally posted by RogueJSK:

quote:

Originally posted by radioman:
Will our polymer handguns (Glock, H&K, M&P 2.0, etc.) have an issue, like 20 to 30 years from now where they change color and become brittle or otherwise change for the worse, like the old computer plastics?

Keep in mind that polymers have been used in gun receivers/frames for quite a few decades. There are 60 year old Remington Nylon 66 rifles with polymer receivers, and 49 year old HK VP70s with polymer frames, and those still work just fine.

I have a 30 year old Glock 19 (made in 1989) whose polymer frame is still as good as the day it was made.

I agree, and no, I wouldn’t expect long-term issues with polymer framed firearms. Firearm frames are typically some version of glass-filled nylon rather than the less expensive, lower performance polymers used in keyboards, etc. Nylon will yellow but the carbon black pigment used in firearm frame resins helps block out UV light and hides any color changes.

Michael

My Cessna's I have owned all had that stupid beige plastic on the interior and it all turned a nasty and brittle brownish/yellow. Best thing I found was to remove it, wrap in a nice color leather and reinstall.

Nothing to do with computers but I have no idea why the old stuff turned.