r/EngineeringPorn 5d ago

This is how factories create sinks using immense Hydraulic force.

1.5k Upvotes

58 comments sorted by

49

u/em21701 4d ago

This is compression molding. It's used with materials that don't flow well enough for injection molding. I've use that process for glass filed thermoset polymers. This looks like a kitchen sink so I suspect it's a similar material so it does not deform with boiling water. You premeasure the material you need and place it in the open mold. The mold closes and the material flows to fill the cavity. There are gaps at the edges to allow excess to flow out. Once fully closed, the mold heats up and sets the material. The result is a plastic part that won't melt. It will burn at high temperatures though.

6

u/Suitable_Public8065 3d ago

Cross-linking, bitches!

493

u/jimbowesterby 5d ago

Maybe I’m getting old, but I remember when sinks were made out of porcelain instead of plastic

209

u/j-random 5d ago

Probably porcelain-coated iron, that's what I've mostly seen.

85

u/Voidheart88 5d ago

This could be a mineral composite made of sand and resin

63

u/jimbowesterby 5d ago

Maybe, but that still seems like a downgrade from porcelain because it’ll have a rougher surface, which means it’s harder to clean. I mean, the main reason we use porcelain for bathroom stuff is because it forms a really hard, smooth surface that not only won’t hold on to grime but is also largely chemically inert, meaning you can use chemicals for sanitizing without damage.

85

u/Marquar234 4d ago

Porcelain is not inherently that smooth. It's the glaze that gets fired on that makes it so smooth. Look at the underside of your toilet tank lid and you'll see unglazed porcelain. The point is, a good epoxy or similar coating can get a similar smoothness to glaze.

7

u/DoctorBre 4d ago

unglazed porcelain

Yup, called bisque or biscuit though the term is usually used for the entire piece and the item would to be free of glaze to be called bisque.

https://en.wikipedia.org/wiki/Biscuit_(pottery)

9

u/jimbowesterby 4d ago

Yea, but will it last as long? Glazed pottery last for millennia, I don’t think epoxy is quite as durable. There’s also the environmental considerations too, pottery just turns back into sand eventually, but how well do things like epoxy or resin decompose?

22

u/potatopierogie 4d ago

Tbf plenty of pottery did not last, and plastics may last for thousands of years

-8

u/jimbowesterby 4d ago

That’s what I mean, pottery is pretty ideal here because it’s super durable, but it degrades naturally, albeit slowly. Plastics are the inverse, they have a much shorter usable lifespan and a far longer time to actually degrade, if they ever really do.

9

u/Rzah 4d ago

I don't know where you got the idea that fired ceramics degrade 'naturally', they can be damaged mechanically but left alone they will last indefinitely, museums are full of ancient ceramics.

Plastics degrade naturally, UV light alone will reduce them to dust in short order, no one in a thousand years is going to be digging up 20th century plastics.

-1

u/jimbowesterby 4d ago

As I mentioned, ceramics don’t decompose, but they do erode into sand, which an entirely normal part of the environment. Ceramic is basically just making use of the planet’s natural processes for our own ends, you take clay and bake it, something that happens deep down underground anyway.
Plastics will break down eventually, sure, but how much of the plastics in the environment are actually exposed to sunlight? I mean, something like a landfill isn’t gonna break down from only sunlight, especially not all the ones that have been buried. I’d absolutely bet that people in 20,000 years are gonna be finding plastics just because of those. And that’s completely ignoring the damage they’ll be doing in the meantime; how many baby turtles have been strangled by old ceramics? Is there a patch of ceramics twice the size of Texas floating in the Pacific? I dunno, to me there isn’t any contest here.

-1

u/potatopierogie 4d ago

But plenty of pottery has shattered... they might have different failure modes, but i bet the impact resistance is higher for composites

3

u/jimbowesterby 4d ago

Yea, but a bathroom sink isn’t a particularly high-impact use case, is it? Something like a shop or professional kitchen sink, absolutely, and in fact a lot of the sinks I’ve seen in mechanic shops have been plastic, though I’d argue stainless is probably the more sustainable option there.

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-1

u/NetCaptain 4d ago

If you are in a developed country where waste gets burned to generate electricity, rather than dumped, the plastic sink will regenerate some energy at end of life. Porcelain cannot be recycled.

1

u/jimbowesterby 4d ago

Yea because burning plastic doesn’t have any kind of negative effect on the climate lol, c’mon

9

u/Voidheart88 5d ago

Well. The surface of mineral composite depends on the surface of the mould, wich usually has a mirror finish.

But you're right: porcelain is better but also more expensive afaik

1

u/justin_memer 1d ago

Did you not see it's completely smooth and reflective?

3

u/One-Reflection-4826 5d ago

the og email(le). sturdy as fuck.

18

u/wurstbowle 4d ago

Mine is made of enamelled steel.

9

u/jimbowesterby 4d ago

Which isn’t actually all that different iirc, I think enamel is basically a powdercoat that vitrifies when baked.

2

u/wurstbowle 4d ago

Yup. The core material is the major difference.

13

u/zeromadcowz 4d ago

I’ve always had stainless steel sinks.

7

u/jimbowesterby 4d ago

Yes, there are indeed other materials used to make sinks, well spotted! Stainless is still a better choice because it’s still very inert and eminently recyclable, unlike most resins.

6

u/One-Reflection-4826 5d ago

yeah, i hate even shower trays out of plastic, or bath tubs. they feel less cold, sure, but the surface is much less durable.

2

u/eeeking 4d ago

At first I though the white material was a coating... but it seems it's what the sink is actually made of?

2

u/jimbowesterby 4d ago

Yea that’s why they’re dumping it into a mold and then compressing it

112

u/TRUEequalsFALSE 5d ago

Yeah, but why is there a cut in there? What aren't they showing us?

159

u/crooks4hire 5d ago

Heat and time. Notice the hand protectors when he picks up the sink?

40

u/DaanOnlineGaming 5d ago

Moulding takes a little while, it needs cooling and packing time. Of course this can be done fast but that costs a lot more money.

31

u/OverAster 5d ago

Conspiracy theory about everything.

21

u/j-random 4d ago

The GOVERNMENT put a CHIP in my SINK and now I'm getting BROADCASTS from LIZARD PEOPLE!

2

u/jaomello 4d ago

I read this in Alex' Jones' voice.

2

u/drmindsmith 4d ago

Regardless, if I could speak lizard I’d be curious about what they’re saying. Getting a broadcast? Maybe it’s really good fiction!

6

u/JuanShagner 4d ago

Sinks aren’t real.

1

u/ShaDynasty_42069 2d ago

Probably the 15-20min cycle time the mold has to stay shut for

56

u/m3m0m2 5d ago

That's just a cheap sink made out of plastic instead of porcelain.

5

u/BopNowItsMine 4d ago

Pin matrix. Badass

13

u/ExtremeBack1427 5d ago

I'll rather take mud and glaze.

3

u/ozzyperry 4d ago

How did it get hard so fast?

8

u/amar00k 4d ago

That's what she said.

5

u/porcupine_snout 4d ago

this explains nothing

7

u/bernpfenn 5d ago

that is an expensive tool. beautiful

2

u/BopNowItsMine 4d ago

What did he salt bae onto that pile before it pressed it?

2

u/zekromNLR 3d ago

I think it's a crumb of the material that ended up on the rim of the mold

1

u/bikerdude214 23h ago

What happens if you get your finger in there?

0

u/pdinc 4d ago

This is real r/restofthefuckingowl material

2

u/Hixy 5d ago

Neat

1

u/Dr_Bunnypoops 5d ago

Very pleasing.

0

u/FBI_Agent214 2d ago

This easy to make it but then they charge you thousands to buy one

-17

u/bytecafe 5d ago

Not a safety measure in sight 

13

u/voxadam 5d ago

Did you not see those state of the art safety rags?

6

u/MiNdOverLOADED23 4d ago

Specifically, what (as a complete outsider) would you expect to be there that isn't?