For everyday objects, it is easy to print with PLA filament or ABS. These are the 2 most common (and cheapest) types of filaments for personal 3D printers. But for kitchen utensils, there are some recommendations to follow.
We explain the reasons and how you can limit the risks with 3D printed pieces in your kitchen through a series of questions/answers.
What are the risks associated with using objects made of 3D filament to cook?
When you have to list the problems associated with the use of printed parts in the kitchen, you refer to hygiene issues.
A kitchen utensil should be perfectly clean, and ideally disinfected to limit microbial development and the risk of food infection.
In the large family of bacteria, many people love hot and humid environments: exactly what’s going on in your kitchen! This is the main reason for the very frequent cleanings! Is this disinfection possible with a 3D object printed with filament?
The problem of diapers
3D printing is an additive manufacturing technology, which consists of “mounting” a 3D object by layering. The layers are glued together, but in reality the adhesion is not 100% complete and so there are gaps between the layers.
Sometimes we can notice that layers are badly superimposed and the existence of holes is obvious. Even if a surface condition seems perfect, smooth, it is actually very rare to have a perfectly waterproof layer. This is the case for FDM as well as for SLS technology (to a lesser extent).
These are places where bacteria, mold or germs can easily be housed. Therefore, the first risk associated with the use of additive manufacturing is not being able to ensure the perfect cleanliness of the tool.
After these remarks on surface condition, let’s now look at the risks associated with materials used in filament.
Low heat resistance
3D printers using FDM technology use thermoplastics. In other words, materials whose physical properties change in heat.
It’s very convenient to print in 3D quickly. Unfortunately, the behavior of these materials is reversible. This means you can melt a 3D printed piece by approaching it from a heat source.
Therefore, this prohibits the use of 3D printed parts to heat, cook or store very hot food… Let’s be clear: you’ll never make a baking cake pan, a double boiler bowl, a whip to brag about a custard with your 3D printer.
Finally, you can do it, but you’re going to run into problems!
To check if your material is able to hold a certain temperature, you can pass it in the dishwasher. So you can see at the exit if it is deformed or intact.
The issue of the emanation of fine particles during the 3D printing process has been studied and some recommendations have been made in relation to these issues.
The amount of micro-particles released by plastics during their use in the kitchen is a subject that raises many debates. At the Digital Patisserie, we are not specialists and we do not have a detailed opinion on this subject.
We looked at whether 3D-printed parts in X material released more micro-particles than objects injected into the same material. But we haven’t found any studies on that.
However, we wanted to talk to you about this risk among all the others. Using 3D printed objects using filament is probably in the same risk zone as using a plastic object in your kitchen.
Caution with colored filament
Finally, we would like to mention one last point to consider. This is the color used in the colored filaments.
If you use a filament whose main material can be used for food contact, there is no evidence that the dye used is. We don’t even talk about metallic, iridescent or fluorescent effects…
That’s why we recommend using colorless filaments (sometimes called plain/neutral by manufacturers) to print your 3D kitchen objects.
Relative adhesion of layers, non-heat-resistant material, micro-particle, dyes in filaments that have nothing to do with food… After all that we have just described, can we still imagine that it is possible to use filaments and 3D printing objects to cook? The answer is YES!
Now that we have a better understanding of the potential risks, we now suggest that you think about possible uses.
Are there more or less dangerous uses of 3D printed kitchen models?
First of all, we offer you an exercise: how do you store your kitchen utensils? For many of us, they are grouped by use.
In a pastry lab, you will find on the one hand the specific tools for chocolate, the tools that can pass in the heat, the tools that can be used for cold preparations…
They are usually not in the same materials. This can help us choose the right uses for 3D printed objects.
Ingredients and preparations intended to be in contact with a heat source are usually prepared and stored in metal objects. For example, stainless steel, cast iron utensils.
It makes sense, we come to use the material that is most resistant to heat and has the best thermal conduction.
Apart from a heating in a microwave, very little use is used for plastic materials. The same rule should be applied to 3D plastic printed objects.
Liquids and cold preparations
It is for this family of products that plastic containers are used the most.
When it comes to infusing, storing an iced or gelled preparation, plastic containers are often used. When it comes to cooling a hot preparation, stainless steel containers are preferred.
Solid and cold ingredients
Plastic objects are also used to store dry preparations (e.g. baked biscuits, chocolate etc.)
So we can imagine making 3D objects to contain dry ingredients or to dose/mix dry ingredients.
The special case of chocolate
Perhaps you’ve seen chocolate mold models on forums or 3D file platforms?
Given the risks we listed at the beginning of this article, this is a use to avoid. Indeed, your chocolate will turn around 35-45 Celsius degrees and you will have to leave it in the container for a long time before unmoulding it.
In addition, the mould must be extremely clean to allow a good removal and limit bacterial risks. A promise that’s hard to keep.
It would be such a shame to poison yourself with a homemade chocolate that you will have put so much patience to make… At the Digital Patisserie we advise having to pour the chocolate directly into a 3D printed room.
The best solution is to print a mold positive and then perform a thermoforming (if you want to know more, contact us).
What is the safest 3D printing filament for kitchen utensils?
There is a wide variety of thermoplastic filaments available in reel for FDM-type 3D printers:
- PET and PET-G
PET, Nylon and PC are the most suitable filaments for kitchen utensils each for a different reason. On the one hand, PET and Nylon are plastics suitable for food contact. While the PC is a material that can be sterilized.
If you would like to learn more about the properties of the main materials available for FDM, we invite you to take a look at the well-documented article from 3DHubs.
However, because of the layer technology, regardless of the material used, this will not completely limit the risk of impurities or mold being stuck between the layers.
To minimize all risks, you need to do a post-treatment.
Is there any post-processes suitable for filament-printed utensils?
As said above, one of the major problems of 3D filament printing is the existing space between layers. There are products (often acetone-based) to smooth diapers, melt plastic and some thought this might be a solution.
This is not, as there is a risk of ingesting acetone using these products, which we strongly recommend you avoid.
Another solution is to warm the wall so that it melts. This is what happens, for example, if you use PLA as a mold positive in a thermoformer.
However, there are releases of burnt plastic odors, detail is lost in the geometry and the process is not controllable … we melted several pieces.
In the end, the best solution is to apply an epoxy resin suitable for food contact. It is a two-component resin that should be used before use. It’s possible but it’s ultimately as heavy as using silicone.
Using silicone is our preferred solution when printing utensils that will be in prolonged contact with food. And in the end, it requires an installation quite similar to epoxy resin.
If you’ve never made silicone, we’ve put you together in a dedicated article our selection of tutorials.
I only have PLA or ABS at home: what to do in the kitchen with?
As we tried to explain in this article, it is possible to use PLA or ABS filament. We advise you to limit the use to specific 3D objects.
For example, you can use them to make cookie cutters. Because the food is going to be in contact for a few seconds with the 3D object. In addition, the ingredients are cold, which limits the risk of micro-particles.
In any case, it is advisable to properly disinfect before or after all your 3D printed kitchen utensils.
If you are looking for free 3D models, we have made our own selection that you can easily print with filament.
And you, what precautions do you take with your 3D printed objects when you cook?