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Plastic cases that go sticky

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Zero999:

--- Quote from: Halcyon on February 24, 2024, 12:36:57 am ---I've used citrus-based cleaner with ethanol (sometimes sold as air freshener sprays). It works remarkably well on anything sticky. But be careful around areas that have printed text, labels etc... as it will erase those too.

--- End quote ---
Be  careful with some plastics. Citrus oil contains limonene which can dissolve some plastics. Most notably polystyrene but also ABS, which contains styrene and is commonly used in consumer goods.

There's even interest in using it for recycling polystyrene.
https://www.chemicalonline.com/doc/new-recycling-process-uses-limonene-to-dissol-0001

807:
Thanks for all the suggestions, and some interesting info.  :-+

I did try the Cif bathroom/kitchen cleaner, as I had some here. It helped to greatly reduce the tackiness. It is almost "normal" to the touch now, but not quite. There's just a slight bit of tackiness still. Just enough to be annoyingly noticable. I might give it one last go with the Cif, perhaps with the rough side of a washing up sponge this time. I would rather keep the labels intact, but if they get rubbed off then it's not too much of a hardship. I know what the buttons do.

On a similar note, it was mentioned in a previous post about rubber feet. I have a few Racal Dana 1998 frequency counters. A couple of them have metal standoffs at the back to protect the connectors. The standoffs have (or had) black rubber bumpers on them. When I was rearranging my test gear a few months ago, I took the counter off the shelf & stood it up on the floor. When I went to pick it up, it had stuck to the carpet! All 4 bumpers had turned into a gooey mess, like thick tar. Some of it had even run down the back of the counter.

Gyro:
A dusting of Talc can be used to reduce the residual stickiness, but is a temporary measure as it will eventually soak up the plasticiser and add to the mess.

tooki:

--- Quote from: Nominal Animal on February 24, 2024, 10:38:24 am ---
--- Quote from: tooki on February 23, 2024, 06:00:24 pm ---Besides, plasticizer migration works the opposite of how you think: it migrates from soft plastics to hard ones and softens the hard ones. Plasticizer migration would result in the plastic going soft, not in the rubber going gooey.

--- End quote ---
Yup.  The worst offenders (as in way too much plasticizer) in my experience are fake "silicone" leads, which are really just overly-plasticized PVA.
The result is that if you keep them in a plastic box, the lead can literally meld into the box, due to the plasticizers.

--- End quote ---
I assume you mean PVC? (PVA is the water-soluble polymer in white school glue and wood glue.)


--- Quote from: Nominal Animal on February 24, 2024, 10:38:24 am ---I often want softer multi-strand wires, and don't usually need the high temperature capability of silicone leads, so I wouldn't mind them being PVA or some other non-silicone plastic, but the migrating plasticizer makes them annoying to store; they need to be stored away from anything plastic, including cutting mats and such.

--- End quote ---
FWIW, the softest PVC wires I've found that you can buy today* are the LifY from Kabeltronik. Many manufacturers make LifY, but most use the coarsest stranding allowed under the LiFY wire code. Kabeltronik uses much finer stranding.
For example, for 0.25mm2:
Standard flex LiYv for reference: 14 x 0.15mm
Helukabel LifY: 65 x 0.07mm
Kabeltronik LifY: 128 x 0.05mm

For larger cross-sections (0.75mm2 and up) Lapp also resells really nice, super soft LifY.

Wire stranding alone doesn't tell the whole picture, but the Kabeltronik and Lapp are really, really soft.

I have a feeling that newer wires and cables are stiffer in general. To some extent that may be to make them environmentally friendlier, but I think a lot of it is just companies being cheap.

For example: at work, I found three reels of RG-174 cable. Two from Huber+Suhner (Swiss made, currently around $400/100m) and one from Tasker (made in Italy, around $100/100m). Despite both being the same spec, the H+S one is nice and soft, with smooth, flexible PVC insulation, while the Tasker one is stiff, with rough, matte, inflexible PVC insulation. The Tasker's insulation is admittedly easier to strip, but for test leads and the like, I have to use the H+S. I'm not sure why the flexible PVC would be more expensive, but it must be...


*At work I have a few old spools of Swiss-made Soflex PVC wire that is super-flexible. It also uses the 128 x 0.05mm construction. But the company that made it was sold multiple times over the years and as best I can tell, hasn't been made for many years, even before the current owner, Nexans, closed the Swiss wire plant. Nexans doesn't appear to super-flex wires at all, they seem more focused on electrical installation and transmission.

AndyBeez:

--- Quote from: 807 on February 24, 2024, 12:23:46 pm ---... All 4 bumpers had turned into a gooey mess, like thick tar. Some of it had even run down the back of the counter.

--- End quote ---
I feel your pain! It seems that this type of 'rubber' turns into a crude oil slick, just because it can >:(
This is also a self-destruction failure mode for drive belts inside 1980s cassette recorders.


--- Quote from: Gyro on February 24, 2024, 12:55:54 pm ---A dusting of Talc can be used to reduce the residual stickiness, but is a temporary measure as it will eventually soak up the plasticiser and add to the mess.

--- End quote ---
Talc is very good for capturing the gunge before it's scrapped off using a dead bank card. I tried sawdust, but this just makes a mess on the bench :-\

Despite the soft-feel coat being prevalent on many electronic devices made in China over the last 25 years, there is little information around as to what it is. One source suggested the material is a type of organosilane acrylate which, after application to a hard plastic surface, is 'baked on' using strong ultra violet light. This is when the soft touch surface texture forms. So it might be interesting to see what happens if a sticky case is exposed to strong UV light - is the degradation re-reversible? Interestingly, the soft surface is meant to be inert to solvents, detergents and alcohol. Which is why it is recommended for use in sanitary sensisitve consumer products like children's toys, phone cases, wearable tech and even, haptic toys for adults :o

Below, this is a pair of magnetic cupboard lights that are suffering severe degradation. In fact, they are so sticky, they can stick to the side of the fridge without using the magnets! I will clean them up over the next few weeks and hopefully report back. At time of writing, I have the sticky shells inside a bag of talc, which should help to soak up the worst of the crap. On the photo, see how the colour from the black plastic button has migrated into the sticky surface. Some weird chemistry going on.


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