Is newer plastic just as bad as 90s plastic?

[3lectr1c]

We all know that the plastic used in the 90s stunk across the board. I mean, just look at all the laptops from that time and try to find one that doesn't have hinge issues, whether it be broken screw standoffs or stress-cracking around the display housing. This has always been an issue we've assigned to 90s ABS, and most people have the idea that "the plastic they used in the 90s was junk" because while not so when new, it's now as brittle as a corn chip. Earlier plastic from the 80s doesn't have this problem. No one is talking about Apple II cases turning to dust, but what is becoming apparent is that plastic from the late 90s is beginning to fall to this fate. My Dell Latitude CPi manufactured in mid 1999 has the stress cracking around the display hinges, Clamshell screw standoffs are breaking, and so on. This provokes the question, is plastic from the 2000s going to begin to fall to this plague? What about ABS from the 2010s? Is it only a matter of 20 years before this stuff begins to break down? And if so, why is the really old plastic so much better? If it's BFRs, that doesn't exempt Apple II and early compact mac cases which yellow just like the later stuff.

Of course, bad plastic is always bad plastic, and plenty of new stuff is junk. I've got a dell laptop from 2014 that has a bunch of broken clips around the housing, very small ones that shouldn't have broke from the stress it was under, but plenty other plastic is clearly higher quality and doesn't do this.

Any thoughts?

 

[Yoda]

A bit of an exhumation on this, but, I've experienced fragmenting plastics on as late as 2009 MacBooks, where several that I know of were breaking apart on the wrist rests and front edges.

I also have a 1988 Zenith 'laptop' which is as fragile as anything else I've seen - including suffering broken standoffs and sheered-off screw mounts. One of my two Apple IIc models is also very fragile, and that's from 1984.

What I think one could conclude is that there likely isn't an era of plastics which was all that great, if only because nobody really had expectation - certainly not 30 or so years ago - that these computers would last more than a year or two. The speed of development and advance at that time was so great that it's improbable anyone tested the plastics for longevity, or expected it to matter. Plastics were just easy to work with and cheap to use.

More modern systems do seem to fare a little better, but that is really more to do with materials engineers figuring out how to imbue case materials with better elasticity, in order to withstand longer lifetimes of handling. A good example of this would be the OLPC XO-1, designed for use by children in harsh climates. While these were pretty useless laptops in our perception of what a laptop ought to be able to do, the casings were plastic with some rubberized finishes, and because they were designed for difficult conditions, they hold up incredibly well.

Apple's attempt at the same kind of thing, the eMate, 10 years before, is all creaks and groans, with harder and less flexible case materials. That they do seem to survive despite being used in classrooms, suggests that even in the 90s, they were coming to terms with plastics as a problem rather than a solution, and that if there had been a motive for manufactures to do so, they could probably have made more rugged and structurally competent systems.

The problem is that plastics are not a good material. You can fabricate plastic with excellent tensile strength, but it will tend to be friable, so over time it will fragment, or you can fabricate plastic with good longevity, but it will tend to warp and fail to protect the boards and screens inside. In between is a fairly narrow band of brittleness vs flexibility, which is where designers pitched their products for years, without finding a great answer.

Shape plays a big role too, however. The aforementioned XO-1 is small and rounded, so it tends to spread torsional loads and impacts well in comparison to something like - say - Dells or Thinkpads of the time. Being larger and more squared, they don't shed or spread load at all well.

 

[Certificate of Excellence]

I'm no plastics expert but I thought this was an easy & informative read on plastics/polymer behavior.

Mechanical Properties of Polymers

www.pslc.ws

From what I found on the interwebs, the brittle nature of plastic is a condition of aging. That polymers over time become stronger by bonding between polymers creating macromolecular chains. This makes them stronger over time and with that they lose flexibility and become more brittle. With the depth of the industry and type of plastics out there, I'm sure there are more reasons than just this like oxidation and exposure etc. and then of course combinations of those but I found it interesting and surprising that plastics continue to create polymer bonds as they age. Anyhow, neat thread.

On a side note, my curiosity did find some neat plastics subtopics like newly engineered biodegradable plastics, water-dissolvable plastics and some new 100% eternally recyclable engineered polymers. Neat stuff for sure if you're into that sort of thing.

 

[3lectr1c]

I don’t know the next thing about how biodegradable plastics work, but that brings up thoughts of micro plastic issues… those probably don’t though.

but yeah, plastic stinks. The one laptop I can sleep easy about is my Latitude CS. Its back display housing is made of magnesium, meaning it won’t ever crack, ahhhh.

 

[Certificate of Excellence]

I don’t know the next thing about how biodegradable plastics work

They read like a current day evolved version of TOTC corn plastics like the stuff folks use to make biodegradable trash bags for composting etc. Some neat stuff out there. The water soluble stuff is a synthetic polymer but is not technically a plastic I guess. It dissolves in water and came about because of all the microplastics floating around in the ocean and water ways. This product which is perfect for a lot of that type of single use packaging application (think amazon bag) would just dissolve away instead of endlessly circling around the worlds ocean gyres breaking down into poisonouse consumable micro plastics.

Anyways, getting off topic, so I'll stop there but neat innovations out there.

 

[retr01]

Regarding ABS, it has been around since the late forties in the twentieth century. It has advantages and disadvantages, such as being readily available and cheaper yet less resistant to chemical changes. The overview of the ABS:

ABS is a styrene-acrylonitrile copolymer whose properties have been altered by the introduction of butadiene rubber. It is a multipurpose thermoplastic that finds relevance in many manufacturing processes, including 3D printing. ABS is notable for being recyclable, durable, and malleable at a specified temperature. It combines the attributes of its components as described below:​

• Acrylonitrile is resistant to heat and chemical reactions and also offers age stability.
• Butadiene helps it maintain its shape, toughness, and impact resistance.
• Styrene helps ABS hold up during processing.

ABS was first used to manufacture bullet-proof plastic sheets in the mid-1940s. It was patented in 1948 and commercialized in 1954 by the Borg-Warner Corporation. ABS is used in high-strength applications, including pipes, keyboard keys, fittings, vacuum cleaners, toy bricks, helmets, and wall socket faceplates. ​

​

An ABS filament will not melt or stick to itself until its temperature surpasses 100 °C. Unfortunately, the print will warp or twist out of shape if the printer doesn't reach that temperature. This damages the build plate, which may peel off or crack. ​

​

Any piece that needs refurbishing or machining will be better off if it is made of ABS, which is excellent for post-processing. The filament can be dyed, or the final part painted in any color. ​

Source: https://www.xometry.com/resources/3d-printing/abs-vs-petg-3d-printing/

 

[Paralel]

Unfortunately, as I have lamented previously, we don't appear to have a material scientist, or polymer chemist, in the 68k community, at least of which I am aware. It would be wonderful if we did since it is likely that they could possibly offer insights on storage that could possibly slow down this process, how old plastics might be stabilized, or even reverse the condition with the right application of external factors such as chemicals or heat.

 

[Yoda]

There was once a very detailed and technical discussion somewhere in the vintage systems community on plastics. It was specifically related to retrobrighting if I recall, but ranged over a number of associated topics.

It went over my head of course, and I don't remember where it took place. The subject does pop up, but that particular discussion carried over several pages, and got very deeply into the chemistry of plastics deterioration.

 

[3lectr1c]

VCF forums somewhere?

 

[Yoda]

That would be a good guess I think. Not that retrobrighting threads don't crop up almost everywhere, but that one was lengthy and quite expansive if I recall.

 

[retr01]

There is a PDF document linked in this article that discusses the scientific processes of some methods of retrobriting:

A Deep Dive Into The Chemistry Of Retrobright

Considerable effort is often required to rejuvenate the yellowed and grungy plastic cases of retrocomputing gear. One generally does well to know their enemy in order to fight it, though, which is …

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