Light Switch Plastic

I think they used to be Bakelite, and now Melamine (?). They should be electrically insulating, fairly rigid but not brittle, not subject to creep, and not moisture-absorbing.

Thanks Tornado, Are there any fire resistant qualities Melamine has? Are there any alternatives nowadays to Melamine?

Hardly any electrical devices are made from Melamine - Wikipedia, the free encyclopedia any more in the United States. It is a thermosetting plastic and is more expensive and harder to process than modern plastics.

Most devices are made from thermoplastic materials, some with mineral or glass fillers. Additives can render these plastics non-flammable, but they might melt, under sufficient heat.

Melamine would not melt, but it would give off more toxic fumes as it chars and or burns. It may still be used in some applications, but not many.

Polyester, polyamide, polypropylene, and even acrylonitrile butadiene styrene might be used. Each of those have trade names.

You'd need to ask the specific component maker what they use.

Your use of the term "mains" leads me to believe that someone from England my have a better answer.

Del the Cat and JohnDG come to mind. I'm sure there are many others.

Cheers.

Thanks Lyn, On the money as always.

Would like to hear from the guys from England.

Keep off the carbon fibre reinforced plastics - ;-)

On a side note, based on your previous posts, you do realise any light switch you make will need to be tested at a certified testing laboratory to ensure it is safe and that the plastic used passes flammability tests?

I am alarmed by your "need to know"!

But you can buy and read the various standards for most countries online. The British Standards (B.S.) for example. They must be followed and all products must be tested by an accredited laboratory, not cheap and you have to pay, or the product is immediately illegal.....

It would appear that you may be considering "Faking" some products (please accept my apologies if untrue!), as many are doing in the far east already.

People have been physically harmed by fake electrical plugs in the UK for example.

Here is a video of a fake fuse for a UK plug:-

Fake UK Plug Fuse Test

Everything is faked nowadays.....please do not add your talents to this huge problem....it can kill.....

If you search on YouTube using "Fake Britain", there are dozens of videos on "Fakery" in the UK. Other countries are also affected of course.....

As someone who actually worked in a testing laboratory testing these products I thought I would briefly mention standards rather than get into specific details regarding plastic compositions.

If it isn't going to get tested then you are not going to be getting much further help from me either.

;)

The MK catalog states: "Logic PlusTM products are made from a high grade thermoset material which has an inherent antimicrobial property."

Elsewhere in the MK literature it states: "The widest selection of wiring devices in one range, made from urea, which has inherent anti-microbial properties."

Its this "thermosetting plastic" bit thats causing me some confusion. I cannot find one particular recommended or even common compound mentioned on the net and all I want to know is what is the most common, quality acceptable material everyone else is making white light switches, plug sockets etc. etc, out of?

For example to the question "what's a coke bottle made of?" Answer "PET"

Not so, in my experience, for light switches.

Even BS EN 60669-1 doesn't have a list of suitable plastics.

Would have thought this knowledge would be more readily available.

I mean the qualities you are looking at Good electrical insulation, low moisture penetrance, fire retardant and low toxic fumes. Oh and cheap and easy to mould.

Does any particular plastic come to mind?

PS: I am not an engineer or material scientist, just some guy in th UK with a light switch idea, trying hard to turn it into reality.

Thanks for the explanation:-

PS: I am not an engineer or material scientist, just some guy in the UK with a light switch idea, trying hard to turn it into reality.

Why not approach an experienced manufacturer with a properly written Non Disclosure contract?

Also, for development, use properly made sockets/plugs/whatever and "adapt" them in a safe manner to allow safe usage....then go for the NDC......

Its a difficult business....

Did you see how you came over as a "future Faker"......as you should have given your comment above in the original question, but better late than never!!!

"Its this "thermosetting plastic" bit thats causing me some confusion."

That might be because there is no such animal when you start looking at industry papers. ThermoSET and ThermoPLASTIC mean different things, I usually explain it to family with the butter and egg analogy. Butter is thermoplastic, you can change its state back and forth freely, melting a stick of butter, then cooling it down into solid butter again, then melting it again. Egg white is thermoset, once you gook the egg white, it becomes a solid and you cannot turn it back into liquid egg white.

If you're looking out on the internet, I'd suggest throwing the phrase 'thermoset resin' at your search engine of choice, since the wide range of materials the public calls 'plastics' are best described in industry terms as resins, you have thermoset resins, such as 'two-part epoxy' and thermoplastic resins, such as polypropylene.

Thanks for opointing that out. Will search for thermoset +/- resins.

Going to speak to a company that offers plastics advice consultancy today. Hopefully will find out what the most commonly used material for elecrtical fittings is, at least in UK.

Mehram, Would I be correct in guessing you have a consumer item you would like to get mass manufactured?

Quickest way to get success (in my humble etc, - not that I would know) would be to mock up a sample, irrespective of B.S. & all that bs; with a good sample you can get provisional orders from local importers or retailers, take the orders to China; manufacturers there have all the standards, and the plastics. They will give you a price / qty delivery; but you have to be very specific on design details etc or they will fill in the blanks any way they choose, or can.

Good luck. BTW; I have a design fitting the same (broad) description, but odds they are the same are very low.

Interested to know how you go.

Hi Stuart21, Got 3D prints of the device and keen to get the moulds made in UK and compre prices for the actual moulding in a few countries.

If I can get the right plastic then can send prototype for BS testing whilst showing the device to future buyers etc.

Good luck with yours.

DO NOT get molds made until you have settled on the question of thermo-set or thermoplastic materials.

Thermo-set resins are more expensive and have vastly different molding characteristics than thermoplastics.

Tooling for each type of resin is very different also. Most importantly, cycle times are much faster for thermoplastics and the left over sprues/defective parts can be reused.

Thermo-sets are only good for one molding. All leftovers must be discarded.

Even shrinkage of different types of thermo-sets and thermoplastics are different enough to matter.

Settle on a material first.

In the UK you may need thermo-sets depending on the requirements.

Antimicrobial properties may only be required for hospitals.

These are all things you need to know before getting molds made.

Mehram - have you got IP registered? Try a 3d design registration perhaps, - patents have been a bankrupting nightmare for me. They may be more orderly for UK / EU. A lot of trouble comes from trying to patent in too many countries.

Really you need the assistance of an existing manufacturer. Is finding a trustworthy one possible? Australia has one or two manufacturers - the one I do know of does not respond to offers of 'sharing' an invention. Even when introduced by their MD's former uni prof.

As to manufacturing, is it possible to have parts manufactured elsewhere, and assembled by yourself or under your control? Even having finished product delivered to you in bulk, packing / packaging under your control would give you a bit of protection. But you would still need good IP to stop 3rd parties - they WILL come.

Lend you some of my IP - mark it 'Patented by Smith & Wesson'

Yes, have used it ;-)

Stuart.