anyone here work with plastics? as in, machines or cuts or otherwise works with them?
where do you buy things like cast acrylic sheet, acetal delrin rod or sheet, lexan, or other such materials?
I ask partly out of curiosity, and partly because I'm thinking of working on a few projects that'll require working in plastics.
projects like;
tabletop gaming tokens
Fetish Equipment
home-made gaming equipment.
what cool stuff have you done working in plastics guys?
what are some things that someone working with various plastics need to worry about?
how would you rate the stuff you've worked with in terms of workability?
what's what in Flexibility, impact resistance, overall strength, or other details?
anyone with experience laser-cutting any of these?
>>959277
>what's what in Flexibility, impact resistance, overall strength, or other details?
I can answer these. I go to school for plastics
>>959277
mcmaster.com
If they don't have it, you don't need it.
>>959277
I use it for making air gun upgrades and things. Generally delrin or similar.
My suppliers are in the UK, so probably not much use to you, but it's easy to get. Some types of engineering plastics are dearer than others, peek is usually the dearest I think.
Easy to work with, I have a wood lathe and I turn it down on that, but then I don't need super tight tolerances.
Generally speaking, if you have the tools to cut wood then you can cut any of the engineering plastics. Heat and fumes can be something to consider.
Very easy to work with, generally very strong and hard wearing, some types are classed as self lubricating.
We also use various types of rubber and plastics on a larger scale at work for lining chutes and hoppers etc on quarrits and recycling plants.
>>959277
Check sites of BASF, DuPont and similar. They have a lot of information on plastics if you look for it. Besides that LG Chem and Samsung SDI have some information on polymers as well.
On where to buy, no idea, depends on the region you're in a lot. But those websites should be able to put you in the right direction.
>>959277
I'm some robotics wannabe who's machined most basic plastic types. I've got HDPE, PVC, UHMW, PMMA, POM, ABS, and PTFE on hand, with a plastic supplier a 10-minute drive away. The listed ones cover pretty much every kind of use, though, so I stay stocked on those.
Quick rundown of each:
HDPE is is cheap, light, and very slippery. My default go-to plastic (mostly because of the "cheap" bit) for anything I don't need a specific property for.
PVC is reasonably strong, has relatively high friction, and is easily solvent welded with off-the-shelf pipe cement. I keep it around specifically for pulleys.
UHMW is basically HDPE on crack. Quite strong, extremely light, and even more slippery. Ideal where you need something light but sturdy, or if you need some kind of bushing.
PMMA is acrylic. Mostly used for cosmetic purposes, due to its high transparency. Bit of a pain in the ass to machine, since it likes to melt in the cut. Use coolant. PMMA is much more brittle than other plastics, so it does poorly with sharp impact.
POM is Acetal/Delrin. Very strong, very easy machining, good abrasion resistance. But strength is the name of the game; if you need to put something under significant load, this is the way to go.
ABS is somewhere in between HDPE and UHMW, minus the "slippery" part. Reasonably strong, fairly cheap. ABS is a very common plastic since it's such an all-rounder.
PTFE is Teflon. Very dense, very slippery and abrasion resistant, high temperature resistance (500°F+), extremely expensive. Not kidding on that last part; my local plastic place sells most other kinds of plastic between around $2.50-$8/lb. The PTFE runs about $25/lb. I was very surprised to find that their $3/lb surplus bins included PTFE. As you can imagine, I bought a fair bit of it. I've not yet made use of its thermal properties, but it's an excellent bearing material.
If you need chemical resistance, check a compatibility chart.
>>959324
what about impact resistance and flexibility?
>HDPE is is cheap, light, and very slippery
milk jug stuff?
seen recycling tutorials...
>UHMW-PE
>HDPE on crack
I have some from the tip at work...boy howdy do i know...
>acrylic
how does this stuff do under impact loads or bending??
>pain in the ass to machine
not if you got a laser or tiny blowtorch nice pretty transparent edges at the expense of some tolerance...
that said I may get some of that for TTRPG gaming tokens and shit like that..
>ABS
isn't that what LEGOS are made of?
>If you need chemical resistance
chemicals they might encounter include, blood, isopropyl alcohol, sweat, water, Trichloroethylene...but not much past that...
>>959316
>depends on the region
near enough to Corpus Christi TX in the USA as makes no difference.
anybody know some store-front distributors in the area?
>>959330
For information about that you should really dive in to material engineering. You should be able to find books and other info through product design courses (check OCW).
Also, all those chemicals are really harmless to most plastics but TCE is a whole different story. It's literally a solvent, it'll dissolve a lot of plastics.
I can just recommend getting Chemistry by McMurry & Materials Science & Engineering by Callister. Those books definitely contain all the information you'd need. Second handed i got them both for 40 bucks for my study, there must be ways to get it even cheaper.
>>959277
Any shop that deals with window glass replacements usually stocks all sorts of fancy acrylics and plastics too.
They'll also cut it to size and save you a metric fuckton on shipping costs when you buy local.
As for cutting, I've only used acrylic. Lasers are wonderful and leave a beautiful polished edge. A regular saw works fine, too. Edges can be sanded then hit with a torch for a slightly hazy but transparent finish.
So happy to find this thread!
I have some glossy black plastic I need to polish. It's from the late 60s but it's not bakelite. I've been wracking my brain and the google dot coms trying to find a way to polish the scratches out of this. I can't disassemble the mic without damaging certain parts, so the heat gun trick is a no-go.
Looked in the automotive shop and the only I saw was the headlight polishing kit, but they're adamant that it's ONLY FOR CLEAR PLASTIC. wat do, /plastics/?
>>959302
Just buy some silicon rubber at different shore hardnesses A5-A80. Or maybe shore O. I dont know what you plan on doing for fetish equipment, and figure out what you like. Make sure it is platinum cure.
>>959330
Get cast acrylic. It has a MW of several million. Good impact resistance from the free volume in the chains. Downside is it wont melt or soften because of the high MW.
>>959330
Ultra High Molecular Weight Polyethylene is just high density polyethylene with chain lengths 100 times longer. Low friction, good impact resistance. Used in football helmets
>>959417
Paint
>>959417
I've been told that unflavored toothpaste works
>I dont know what you plan on doing for fetish equipment,
impact and restraint tools.
>>959438
that was the first thing I was going to experiment with on my laser.
>>959440
I have a couple of strips of that a few inches across by a half-inch thick, makes a good spanking paddle...
>>959330
>how does this stuff do under impact loads or bending??
Very badly. Acrylic is one of the most brittle plastics around. It's actually a really shitty plastic by any typical metric. However, its exceptional optical qualities, inherent UV resistance, and easy solvent welding make it the plastic of choice for anything decorative or optical that doesn't need the strength or impact resistance of polycarbonate.
It's not like you have the handle the stuff like it's glass, as acrylic is reasonably durable, it's just nowhere near as hardy as most other plastics.
>blood, isopropyl alcohol, sweat, water, Trichloroethylene
>Trichloroethylene
...the fuck?
>>959417
You can polish virtually anything that can be polished with a general-purpose polishing compound. It just might not work quite as well or as fast as something purpose-made. Doubt you care too much about that in your case.
Some plastic polishes do more than just abrade, which is why they can't be used for just anything.
>>959330
>blood, isopropyl alcohol, sweat, water, Trichloroethylene
No semen?
2/10 was expecting more out of OP.
>>959450
it's not like I'm making the stuff so it can be used on ME...and vaginal secretions is easier to clean off of things...
>>959447
>the fuck?
my workplace regularly considers a partial bottle of the stuff to be "empty" and so throws it away...I collect the "emptys" from the adjacent departments and collect it in a pickle jar to use when I want something properly clean...
>>959443
no can do muchacho. although i did consider using kiwi shoe polish in the sponge bottle desu
>>959444
>unflavored toothpaste
hmm i'll have to google that
>>959447
this is probably what i should do. something like pic related should work?
>>959452
>collect it in a pickle jar to use when I want something properly clean
Uh...yeah...don't use that on plastics. Stick with bleach. Although I'm partial to HCL myself (easy to get from pool supply and hardware stores as muriatic acid) when it has to be ABSOLUTELY CLEAN. But goddamn you need to be careful with that stuff.
>>959455
>something like pic related should work?
Given that it's a finishing polish (implying a very fine grit), it'd probably take some extra work over a set of polishes increasing in fineness, but I'd expect the stuff would work eventually.
>>959461
>But goddamn you need to be careful with that stuff.
yeah...a month ago I got sprayed directly into the eyes with several ounces at ~~120 PSI...
happy now I'm not blind
>>959286
McMaster is the saddest company on the planet.
In an attempt to "stay new" they hire 20 year old ivy league theater majors and place then in charge of whatever department needs a new manager. Nothing more depressing than 50 year old warehouse workers getting bossed around by a 22 year old fat chick with a degree in women's studies. Pretty soon they're gonna just fall apart which is sad given that their model is pretty neat.
No one likes PP?
It's used for tubs and plastic sacks, because it can be stacked and otherwise manhandled without cracking/tearing and ruining its contents.
Also very flexible - remember the mighty Tic-Tacs lid, it's very thin, yet you can flex it forward and backwards a month of Sundays without ever breaking it.
On the downside it doesn't like UV light and is difficult to machine or thermoform.
But it can be Injection moulded easily, and Blow-moulded or Rotocast with some success.
>>959324
What about PLA?
>>959324
Quality post
>>959555
You can machine PP if you cool it down in the freezer. Glass transition temperature is -10 C. That is achievable. You just need to work fast and repeat the cooling. OR compression mold it with a shop press
>>959561
PLA sucks cocks. From an engineering standpoint, I refuse to work with PLA on the job. It has shitty qualities and only gets pushed on us because that is the only biodegradable plastic that people know of.
>>959600
Oh god, this. I was at a "makerspace" and when I asked why they don't use more ABS, they said that PLA is better in every possible structural way. It's like communist propaganda. I left.
>>959277
I cut plastics on a 3/4-axis cnc mill at work. Lots of PVC, cuts really easily and cleanly.
Starboard/HDPE is a bit harder to cut but not bad, it's heavy as fuck but great in the elements. We use this stuff at work for things that have to be out in the sun a lot.
I'll also cut acrylic but that's much harder and you have to go slower so the bit doesn't walk or do anything funky. The finish comes out pretty good once you dial it in though.
I'd love to try some more exotic plastics also. I've never messed with acetal/delrin or teflon.
>>959277
>Fetish Equipment
example needed
I've ordered from TapPlastics.com. they have a good selection and cut to length, but shipping can be expensive.
>>959838
Yes.
>>959660
I have a 3D printer and my reason for sticking with PLA is that I don't want the apartment smelling like a china factory. But I do know that ABS is generally more flexible & stronger than PLA.
>>959277
>projects like;
>tabletop gaming tokens
>Fetish Equipment
>home-made gaming equipment
Are you opening up a bdsm den/illegal casino? If
>>961211
>den
that would be either a Dungeon or a FUNgeon(technical distinction determined by the severity of the equipage)
and no, I'm looking for lightweight things to add to my portable kits, either as a sadist or as a GM...and on rare occasions a sadistic GM
>>959277
>Fetish equipment
Latex is much better for recreating a BBC.
>>961245
>bbc
context?
latex bugs me...
looking for cheap interesting materials for stuff...
>>961250
I think he means the big block cock
>>961365
...no, my original model insertable seems adequate according to those who've had it...
no, I mean to make restraints, metallic ones look nice, but tend to be uncomfortable, very expensive, and not as impact resistant as you'd expect.
also impact toys...my sub has a case of the ROCK ASS nothing I have up to and including the 4# solid oak paddle I made recently seems to make an impression. that, and wildly variable impact properties means a more versatile kit which is more appealing to the ladies of that particular community. there's only so much being a whip-braider can get you in the Community.
how do the various plastics lathe?
>>961570
Make a carbon fiber paddle with 3/4" balsa core / sandwich construction
My experience with plastics has been chip evacuation is the only trick. If it gets hot it can get stuck on the tool but you should have no problem on a lathe. It'll cut like butter.
>>962169
>Make a carbon fiber paddle with 3/4" balsa core
>paddle, with lighter materials and a thin crosssection
>Raucously_laughing_masochists.png
seriously dude, do you even sadism?
>>962271
It will be stiff as fuck, both by the mechanical properties of the carbon and the added thickness by coring, so less energy will be absorbed by the paddle. If you double your thickness, you quadruple your stiffness.
That's my thinking anyways, but if lots of experience of paddles on asses has taught you something different im all ears.
I'm a turbovirgin so never even got close to anything like sadism.
leaving aside impact properties and paddles.
if I wanted to turn out plastics like Delrin or Acrylic on a wood lathe would I be pulling a stupid?
I'm talking about making handles here to replace broken ones on some tools for a friend.
probably gonna just use wood, but they might appreciate something that won't crack or splinter with age...
>>962380
>if I wanted to turn out plastics like Delrin or Acrylic on a wood lathe would I be pulling a stupid?
Perfectly doable.
Although acrylic maybe not so much. Again, it would be doable, but tricky, due to its tendency to chip.
>>959417
for small scratches in plastic I tytpically use a heat gun. You can get a cheap one (that works well) from Harbor Freight for $10. I've used it on auto dashes, and some appliances. Outside of that, any sort of polishing compound should work (typically just a silicate of varying grit size in solution)
This appears to be turning into a plastics general, and I see some posters who might be able to help.
I want to build a spherical fishtank, about 20 inches in diameter. I realize that'll be a hell of a lot of water and I think I calculated it to weigh about 150 pounds.
I assume the acrylic spheres one can get stock will not hold that kind of weight/pressure. Can I get thicker spheres for less than a bajillion dollars? Or is there someplace that would have that sort of thing stock?
>>965454
>I assume the acrylic spheres one can get stock will not hold that kind of weight/pressure
I'd wager they would, the pressure would be well under 1psig/sq in
>>965481
Is there any way to figure it out without trashing an 80 dollar acrylic sphere?
>>965681
MATH
my suggestion, go to a college campus that teaches engineering and offer a professor(or student) in chem or mech engineering $20 to do the calculations if you cant do them yourself...
Does everyone who works with injection moulding just build their own machinery? The cheapest solution I found in casual searching was a 600 USD conversion kit for a drill press.
>>965454
>I want to build a spherical fishtank, about 20 inches in diameter.
That's nothin'. On top of that, spheres are the best possible shape for containing pressure (all forces on it tensile).
Don't even have to do the math to know that even an excessively thin sphere would hold, but...
Water pressure due to gravity is related entirely to the height of the column of water. That is to say, "inches of water" is directly translatable to PSI, with 1in of H2O being approximately equal to 0.0361PSI. Simply multiply that by 20 to get 0.722PSI. That's really low. Your lungs can manage more than that, even. And that's only the peak pressure at the very bottom of the sphere.
Just ballparking it off the top of my head, I would think a 1/8" thick acrylic sphere to be sufficient, mostly because you'd be much more concerned about how to support 51l (or just over 110lb) of water without deforming the tank enough to break it. Which, really, isn't that much. Just make a ring like...I dunno, maybe 8"-ish in diameter, set the sphere in it, and you should be fine.
>>966478
There are two types who bother with injection molding:
1.) People who are selling loads of something and can afford expensive equipment to do it.
2.) People who need just a few of something with relatively complex geometry (think the board game figurine fags).
The former just buys full-on automatic injection molding machines that you'd be lucky to find under $1000 when BROKEN, and the latter just sticks with the small manual units like you found. Though $600 seems to be kinda on the high end for that.
>>966497
>I would think a 1/8" thick acrylic sphere to be sufficient
Forgot to mention that, while 1/8" would be enough from a structural standpoint, I'd get something thicker if budget allows. 1/4" or so.
My greatest concern would be some random, sharp impact breaking the thing if it was much thinner than that.
