How to make food-safe 3D printed models
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- เผยแพร่เมื่อ 3 ธ.ค. 2020
- You probably know that regular 3D printing is usually considered unsuitable for food contact. But do you know why? And do you know how to make your 3D prints truly food-safe with the surface coating?
DISCLAIMER: Please use stainless steel nozzle for printing food-safe objects. Our hardened steel nozzle may contain lead as well as the brass nozzle.
See our article to find out more: blog.prusaprinters.org/how-to...
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Music: Shane Ivers - Cruise Control - วิทยาศาสตร์และเทคโนโลยี
It's important to take chare when chosing the epoxi resin. just like plastics, there is "food grade" epoxi resin. While not mandatory, it's good to look for a reputable brand and maybe mail them about it. cheap materials from unknown brands can have harmful substances mixed in the resin
All epoxy components are toxic (cancerogenic) by themselves in unreacted form (just read the MSDS on components!) It's down to basic epoxy chemistry. Even food grade epoxy is not food safe if you don't follow manufacturer instructions which includes very precise measurements and most often post processing in form of baking!
@@avelkm Yeah, but what they don't say in this video is that epoxy stays cancerous if you it's old. It doesn't cure properly any more. I dont know if this video is such a good idea regarding food safety with another potential cancerous stuff..
Thanks!
9 out of 10 biologists approve of this use of the heated bed. super cool!
A couple of points regarding the ptfe tube mentioned in the beginning of the video:
1, ingesting ptfe is not a concern. Only the fumes from very high temperatures are toxic.
2. It may be safer to use a used/aged ptfe tube than a new one. When you heat a material that outgasses or leaches anything out, most of that stuff will come out very quickly, but that leaves less volatiles behind. After a while, maybe just a couple hours, the rate of outgassing or leaching will drop to almost none. Everything that's can outgas has done so. So, in this way it could considered safer to use a tube that has already been "baked out" than a new tube that has a higher (new) concentration of volatiles.
3:02 "thoroughly" haha I like your pronunciation more! your English is still much better than my Czech.
Toro (Bull)
Classic English spelling. Where the "gh" in Thought, Rough, and Thorough denotes three completely different sounds.
May I suggest doing a PLA cast video? The idea that you can make many cast able objects with a 3d printer is very cool.
You can pour silicone in, it's possible.
Remember that food contact rules are different for: Quick contact: Biscuit cutters. Short/Medium contact: Bowls/Plates/etc. Long term: Storage containers.
ABS often considered is food safe for the first two under those rules as you wash the tools first. Use them then put them away again. And even leaded pewter while not recommended is fine for short term use, like as cups where the liquid is only in it for under half an hour or so.
I would have liked to see a glass or ceramic control for comparison. I would imagine a washed glass cup would have grown some level of bacteria as well. Ty for the experiment though.
For hand washing, but probably not if you washed the glass/ceramic dish in a dishwasher at normal temperatures.
For real, imo number one rule of a scientific experience is having a control specimen...
Also remember that there is a difference between sterilization and sanitize. Santize remove bacteria to a safe level below the ID number, while sterilization removes all of it.
With hand washing and even disheashing, it has been sanitized, not sterilized. Restuarants require only sanitation. Some dishwashers can sterilize.
The amount of bacteria that grew in the petri dish in the video was not very much, and most of it is possibly good bacteria such as lactobacillus which does occur in pasteurized milk.
There is a lab experiment we do in micro biology class with milk and 30 petri dishes to see what kinds of bacteria grow and how much.
Its all about the type and amount. Ingesting that small amount has been proven to help excercise our immune systems. In one meal, we eat close to 300,000 bacteria and about same amount in other microbes, some good some bad, but its the ID number that we always test against.
If one hand washes with warm soapy water, the glass, a metal spoon, a food grade plastic reusable container, and 3d printed pla all produce roughly same amount of bacteria. Look at a metal spoon under a microscope. Glass is by far the best option if one is concerned, but for 3d printed pla, its not a concern.. except the color additives are for sure not food safe...
But, rubbing alcohol and soapy water can actually get into pores smaller than viruses. Its all about surface tension
Short and sweet video like always. Thank you.
Přesně tohle jsem hledal.
Díky moc, za super video. 👍
What the hell??? Epoxy is not food safe! Even "medical grade" epoxy is not food safe if tech process is slightly off (and it needs baking to finish polimerization!)
Then what about those Epoxy that has a federal seal of approval that is it food safe?
@@uwillnevernoewhoiam It is food safe only in reacted form and only if tech process is followed properly! That means - ratios are strictly followed, temperature regimens are strictly followed, and part is post-processed by baking! (which would ruin pla for sure). If you have 1g of one component more than other in a mix, it's 1g of toxic and carcinogenic unreacted resin that would leak into your food. Don't believe me or anyone else in this topic, always read MSDS on components and manufacturer instructions. I would not trust any epoxy product from home shop and not trusted manufacturer be food or medgrade safe, even if resin is "certified".
@avelkm what about paint finishes
lol
😂 I love the spoof of those crummy infomercial videos. They also show the most inept people lol.
I like that you actually tested them too, instead of just blindly guessing.
Waited for this!
Thanks for the vid. I want to print some more special chocolate molds for my hobby so of course i was concerned about food safety with the plastics. I did a bit research myself but this video brings together all the info i need really nicely in 5 minutes.
Love your printers!!
2 days ago I had a debate on the internet about selling cookie cutters, this video helps immensely
I've been there as well Malakim, the number of people/shops selling 3D printed objects for food use without any consideration for this is worrying.
Bacterial growth is probably not much of a concern for cookie cutters as (I think!) the cutter is used on the uncooked dough. When the dough is baked any bacteria should be killed. Obviously a bacteria laden cookie cutter isn't appealing, but if the cutters are put through a dishwasher just before use and then used on dough prior to baking then the residual risk should be close to nil.
@@Ben-kt5rc That's what I'm thinking as well in relation to cookie cutters. Wouldn't the baking kill the bacteria anyway? I'm not sure how much of a problem that would be?
However I don't think the PLA would do well in the dishwasher. It would probably deform.
Well done. Thanks for sharing.
Thank you for the information!
May be a stupid question, but what does it matter if the filament and extruder are food-safe if you use the epoxy surface coating? Doesn't that completely encase and seal the filament?
Yes, you're right - it will seal the filament. But we wanted to be sure that it's completely safe inside-out. Better be safe than sorry. :-)
Epoxy is not food safe unless 1) it's certified 2) properly mixed and very precisely weighted 3) post processes which includes baking at temperatures that will melt pla
imagine the epoxy coat getting damaged like getting a crack or trying to cut it with a knife, the inside has to be food-safe too. Or the industry would put epoxy in everything but that is not the case
@@DavidGarcia-nx2gj - Which "industry" are you talking about? I'm pretty sure there isn't an "industry" for 3D printed tableware, and ceramic tableware uses much cheaper glazes compared to epoxy resins.
You also dont need to worry about resin on clear pla. As a medical and areospace engineer, we use pla all the time. Soap and water will actually sanitize pla extremely well. The low surface tension of soapy water allows it to get into pores smaller than bacteria, allowing the soap to break appart cell walls and turning them into soap as well haha. 70% or higher rubbing alcohol will do the same. In a facility where a friend of mine makes filters that filter out viruses from blood, they are required by law to use 70% or higher ipa
Were the problem is... not all the additives in pla filament are food safe. This is why resin is a good thing. Do not use spray enamel clear coats either.
Resin, as it cures, can get hot too.. so if you put too much on, you can MELT your prints... Be sure to brush on light layers and then the second, or if you do a third with two very thin layers, you can go a bit thicker. The resin will auto level out on your print and be the same thickness for the most part. But I do this with any resin items, even wood. with anything that can have air in it as it cures, resin will bubble. so brushing on lightly seals those gaps up and on the second or third coat, there is no more pockets for air and your resin will be smooth as glass.
Also, like you stated, resin does wear down and scratch. This makes grooves for bacteria to trap as well!. Be sure to inspect before each use if using as a dish or food safe, and if any scratches or wearing is showing, just clean it and do a new layer of resin on the bottom or inside and good as new!
thanks for the video great work...
Thanks so much!!
👍👍👍 Thank you! Perfect timing. I'm getting ready to make a hamburger press for my daughter and myself. The resin coating will be perfect on the PLA 👍👍👍
2 questions. Are you able to use a 3D printer to print out HDPE plastic milk jugs with caps? If so, how long will one take to print out usually?
Josef Team has done an interesting piece of video. Especially the steel nozzle because bronze can have lead :)
A safe and really nice alternative to potentially toxic resin i have found, is nail laquer.
So, what if you for example use army green, but applied with epoxy resin, will that turn it food safe? Or can whatever unsafe particles mix with the resin and be unsafe? And what resin products can i buy to make it the proper resin for food use? As i have no idea where to get what and what to even get as i'm at a blank slate.
Just fyi, nearly all italian spaghetti is extruded through brass nozzles. There is no meaningful risk of any sort there.
For brass, the ld50 (point it kills you) is roughly 1/4 of your body weight when taken orally. To get this from printing, you'd need to print literally hundreds of thousands of dishes and then eat all of the dishes.
Very interesting! Thanks!
That bacterial joe at the end is funny :)
What about smoothing PLA with dichloromethane / Tetrahydrofurane? Does any of those two make the part toxic? What if I sand the parts and then smooth them? Does that positively impact food safety?
Thank you
Hey, I was wondering something : if you coat your print with a layer of epoxy resin (and you chose food-safe resin obviously) then is it that much of an issue to use a brass nozzle ?
Is there a ceramic filament that can be fired/glazed to be dishwashable and microwaveable and safe?
Great video. The testing was useful information. Epoxy is king. Mahalo for sharing! : )
Thanks!
hardened steel nozzles also contain lead to my understanding. You want the stainless steel nozzles for this.
"Stellar" acting! :D Even better video :) Thx.
how about use the printed part as master for mold.
exaxctly!"!
Nice video !
great one
From the research I have conducted. ABS is food safe and dishwasher safe. All that is needed is to smooth the abs with acetone and then apply polyurethane resin to make it drink safe.
I don't really think about the bacteria part of this problem,
I am more interested in how to seal the cup of a PETG model so it can be used without leaking any how water and so be used as a cup to drink hot tea or coffee from it?
I made a very nice cup for a friend at work and it was done in PETG and printed with a 1 mm Brass Nozzle with a solid infill at 0.32 layer height.
So I need to know how to fully seal the surface of it so it can hold high water, Any thoughts?
Everyone: Ceramics
Prusa: Keramix
😂
LMAOOO got a pretty good chuck or should I say Khuck out of that one. they can make good 3d printers yet somehow didn't master using google translate lol
It is really pathetic to make fun of people doing their best to use “your” language.
How are you at speaking “their” language?
@@Traitorman.14.3 lol I knew someone would comment this. Go be a social justice warrior somewhere else bud.
@@Traitorman.14.3 If you can't understand we are laughing with them and not at them, YOU'RE FIRED!
so if I am using ABS filament and stich back over to PLA fore food safe items will the non food safe ABS filament still linger around contaminating the food safe PLA or no?
sould i run a cupule cleaner prints-test print to clean out the system-printer or once swish from ABS to PLA i will not have to worry about contamination
I'm worried about wear. My knife on a cutting board could say sand away or take out some particles and get added to my food
I wanted to make an espresso tamper but I'm worried about the coating wearing off
Cool video!
I have doubt about cleaning, im planning to create some alcohol beverage dispenser, could I use epoxy and petg for alcohols and in order to clean it inside (pipes) will be required to drop inside boiling water and it need to resist the heat.
If I’m not mistaken epoxy contains bpa.
Yup... usually around 40% bisphenols.
How about polyurethane ?, I read all polyurethane coat are food safe when is cured , they are used to coat kitchen furniture I think is work well and is most easy to work than epoxy resin
What about spoon / fork holders? Is it safe to use 3d printed spoon / fork holders?
Is there a safer alternative to epoxy coating?
Doing everything in my own apartment, I would be exposed for days to epoxy resin.
I want to love this video and would love to be able to make some things i print "food safe". But I use multiple materials to make things and I was using resin long before i started 3d printing. Some resins if PROPERLY mixed and cured are good contact safe in some situations. But you run into the human element. If your ratio is slightly off, your resin could apart fully cured and it actually not be. Then there's the fact that most resins aren't FULLY cured/cured to "food safe" levels for 7-10 days. So even if you get everything right and it looks and feels fully cured, if it's not been 7-10 days it's still not safe to use. I personally don't feel safe using the method. I am however curious if salt smoothing or scraper smoothing would be more viable methods.
It is also possible on resin?
Although it may not be very trustworthy, youtube sources say epoxy resin is food safe only at incidental contact (a few seconds to a few minutes). Does anyone know if epoxy resin (or any other method) is really food safe ?
How do you feel about Taulman's Food safe 680 nylon? as a base material that is
Taulman Nylon 680 should be food-safe, after all - it is a food and beverage rated material under 21CFR177.1500 / CFR177.1395. But still, 3D printing imperfections might make it unsafe. Surface coating or usage only for dry foods might be neccessary.
Do you have any specific PLA/PETG filament brands that you might recommend that have food safe certification?
Not really. I'm afraid that you'll have to do some research yourself. We mentioned PLA by fillaments.ca but there are more food-safe filaments on the market.
filaments.ca/products/true-food-safe-pla-black-licorice-1-75mm?variant=12357714739253
What filament is aquarium safe?
Wouldnt the steel nozzle also have a small amount of lead?
This is a big topic. If 3D printing manages to be food safe it could even become the industrial catalyst everyone was expecting it to be. It would be interesting to see similar analysis for toxicity of UV cured 3D resins. Or maybe they are all toxic anyway xD.
Given how much faster and cheaper it is to injection mold plastic, 3d printing will only ever work for prototyping, and for the creation of personalized items. It does have value in the creation of impossible to mold shapes, but the sheer number of printers you would need to industrialize that item makes it more practical to just make a less optimized approximate of the part you want to industrialize.
Its asa food save if i overpaint with epoxy resin?
have you looked into re-melting using the salt method? Probably would help with the use in the washing machine and with the bacteria
We haven't tried it but it might actually help. If you have any experience with it, let us know. :-)
Is untreated pla safe for toys?
Why only PLA testet?, Whats about
Extrudr
Green-TEC PRO ? This filament ist dishwasher (hightemp) able and also ceritifactet for food? it would be really nice to extend you tests.
We didn't mean to show that PLA is the only food safe filament. There is a variety of food-grade filaments that might be used. We used PLA because it's generally safe and most common filament. Of course, it's best to use certified filament, but still, there are some 3D printing limitations you need to keep in mind. See our dedicated article at prusaprinters.org to find out more.
3:08 My grandma legit has a ceramic bowl just like that one 😂😂😂😂
Can food safe finishes be used?
love it
Shellac flakes disolved ethel alcohol is used on wood, candy, pills, and other food items.
where can i buy some food safe epoxy resin
With the layers and gaps it's a lot like bamboo, right?
Did anyone else notice the tease at the end for their new bio-printer? They showed bacteria growing in the form of their logo. Preorder now! ;)
would xtc 3d be also suitable?
As far as we know, xtc 3d does not have food safe certification. It might be fine but you should contact manufacturer first.
Is the army green pla colored with arsenic?
Methinks they use powdered zombie to get that colour
Please make a video about chloroform smoothing pla
What about resin printers?
If you were to try the epoxy coating just know that it will contain BPA
The resin we used has a food-grade certification so it shouldn't be toxic.
BPA is legally permitted in food packaging. I think the evidence for its harm is weak, but it’s enough that I try to avoid it.
What about clay fillaments?
Have you considered Shellac for coating?
We did think about it but I'm afraid that it wouldn't stick to the surface well enough and would have inferior mechanical resistance. But I might be wrong. If you have some experience with it, don't forget to share it.
Yep, I covered a measuring cup with it months ago. It is mainly used for flour and powder, but we clean it up with water. Till now no foul odor or nasty sediment. The important is to avoid alcohol that can melt the shellac.
I get this but why is wood food safe. Surely it also has little cracks and spots that can harbour bacteria...?
Wooden dishes and cutlery are sanded very thoroughly, and finished with oil.
Guys, when expoxy gets old (about 1 year), it can stop curing properly and becomes extremely hazardous. I think this video should talk about this topic too..
Interesting.
Cool video. I have to make a replacement part for my dishwasher but haven't done it yet since I'm worried of having left over particles from the parts onto the plates and cutlery, any recommendations?
First of all, you need to use heat resistant filament. PETG has heat deflection temperature around 70°C so it might be usable. But if you plan to do a surface coating, you should also look for resin that has similar (or better) temperature resistance to the filament used.
I have experimented with food-safe epoxy resin, but have never found one that promises to withstand the heat of hot coffee, for example. Do such resins exist? I think this is important to address since your video shows what appears to be a coffee mug.
You are right, there is a coffee mug. But we didn't forget to warn about heat resistance. It is not suitable for microwave, dishwasher or any warm food.
@@jakubkoci4626 You did warn against cutting or using a dishwasher and microwave, but I didn't hear anything about warm foods. Could you be so kind as to point out the timestamp since I am missing it?
@@EricLaspe OK, you're right. It isn't mentioned in the video, if you need it blak and white. :-) I think that mentionig that it is not good to put these dishes into microwave or dishwasher shows well that it's not good to expose it to any heat source. Also, it's pretty well explained in the article shared in description.
@@jakubkoci4626 Thanks for addressing that in your article. I realize you're not the makers of these epoxies, so you are not responsible for them. I wish there were some that could withstand the heat, since I know the PETG can. :) I'd love to see a tutorial on printing molds for materials that can fit that niche.
I wish I had a Pursa Printer as they don't sell in India and exporting makes it very costlier.
well his printer is open source so, you can build one yourself
What is "Ke"ramics?
Based on the the morphology of the bacteria, it looks to be human cocci. Meaning that it is more likly that they are comtaninants during the sampleling procedure.
Kind regards the friend microbiology laboratory technician from Denmark :-)
Actually, I did my best to not contaminate samples. I used only sterile equipment and respirator and kept agar plates open as short as possible. I agree that it might be human cocci (we didn't identify the bacteria) but this might mean that these bacteria grew on the surface during simulating the regular dish use. But this might still support the idea that untreated surface is more prone to bacterial growth than the smooth (epoxy) one. Please correct me if I'm wrong. :-)
@@jakubkoci4626 You are right, small recesses, especially when being wet are perfect habitats for microorganisms. The bacteria seen could well be from the printed object, thought a handling error can always occur during a test. Even in professional labs.
In general I think your testing showed it well not to use uncoated prints.
Safety first! Especially when kids are using them.
@@jakubkoci4626 I am certain you did! And I don't disagree with the conclusion of the video, on which treatment is better to prevent unwanted growth of microorganisms. It makes perfect sense from a microbiology standpoint.
I am just saying that based on my experience, it is a possibility that that CFU on the plates are humane contaminants.
No matter how careful you are, that can still happen, even in professional clean rooms.
That said, it is different to determine a microorganism from looks alone. To me it looks like a cocci, as I have previously identified similar looking CFU to be cocci. But you can even have yeast or bacteria that looks like fungi, so it can vary a lot.
Question; did you use the heatbed to incubate the agarplates? :-D
@@Faroth26 Actually yes, I used it for several agar plates. But there was no difference to those that I incubated only in room temperature. :-D
brass nozzles have lead in it?????
I’ve seen people printing fondant stamps for cookie making. They’ve coated or smoothed the stamps with something however they’re printing in such large quantities it makes me wonder…they must be using the chloroform technique?
wait why cant you just dunk them in boiling water? (at least like PETG PLA might melt I guess) I know plenty of microbes can survive past 100c but not commen ones or fungus right?
Boiling water will melt not only PLA, but also PETG and soften even high-temperature materials like ABS/ASA or Nylon. Though in the case of ABS/ASA/Nylon the prints might survive for a few seconds, their heat deflection temp. is around 85-95C. -Mikolas
Those ceramic plates looked heavy!
it would cost much less to just buy ceramic, molded, glass, metal, etc food ware. also want to mention that PTFE is used in surgeries such as for sutures and some types of prosthesis joints due to its smoothness in preventing bacterial wicking unlike braided types of sutures. i recall using sutures of this nature and they are so well biocompatible that it embedded itself in the soft tissue. nonetheless, patient had no negative outcomes and in fact, the surgery went very well and still no issues after several years of follow up. so i dont really know exactly how toxic it is.
I'm in a class called X stream at my middle school,and the teacher said we're going to start 3d printing this Thursday and I want to make a mickeymouse plate for My brother. So hopefully this'll help :D
Any recommendations on how to apply epoxy inside a tube. I want to start making small fountains, but since I have cats that will drink the water it has to be foodsafe.
Maybe use foodsafe tubes inside you models? Much easier and safer and gives you a lot more freedom do design your model any way you like.
There are so many good food packages sold around our food that are save and in the most cases dishwasher save. Better develop nice 3dprinting carriers for them instead messing around with sanding and toxic fumes resin.
It’s food safe to print on a resin printer?😅
Usually not. See the article linked in description to find out more.
Why is ABS/ASA not food safe?
Styrene is a known toxic material. Since both contain it then they're generally considered not safe.
There exist ASA filaments with food-safe certificates! Though they are not cheap...
best solution...print shot glasses and you won't have to worry about bacteria
Basically you CAN but you shouldn't. Looks very hard and not worth it. A better option would be to print a model and create a silicone mold that can then be used for casting In a good safe solid material.
Just a small clarification: The layer lines and inability to be washed at high temperatures make PLA prints not food safe in the long run. Almost any print is food safe once. Serving dishes and utensils for dry applications are generally safe for a few uses if you brush out any collected crumbs.
KAY RAA MIX
Cool video but I don’t think the demonstration is accurate (even if agree with the results) the milk (uth) should have no bacteria anyway, the right method will be to rinse the milk, allow some time to some bacteria grows in the creases then do a print or a lavage onto the Petri dish. But cool stuff nonetheless