In Christmas 2020, I was thinking of creating a cookie-cutter with PLA filaments (the most straightforward option!). So, I ended up with a 3d model from Thingiverse, and it was ready to become a handy kitchen tool. But then, a thought occurred to me that made me hesitate; is it OK to use PLA for cookie cutters?
This article is about what I learned. Long story short:
Is PLA safe for cookie cutters?
Pure PLA is made from corn starch, and it doesn’t contain toxic materials. However, some manufacturers add extra substances to enhance their properties. Some PLA filament brands provide food-grade filaments. Using suitable filaments and following the tips below can make your PLA a safe material for cookie cutters.
Selecting a food-safe PLA brand
Polylactic acid or PLA, as a pure material, is mainly made from sugar cane or corn starch, so it’s a food-safe material in general. PLA filament isn’t 100% pure, though.
Most manufacturers tend to add color pigments and other adhesives to enhance their properties, so the filament may become contaminated and unsafe to ingest.
Hence PLA filaments with natural colors (without pigment) are commonly safer to use. Some filament manufacturers use FDA-approved colorants and provide food-safe filaments.
You can always check the material safety data sheet (MSDS) of the product to ensure whether it’s FDA approved or not. You can also check for other certifications. Popular filament brands provide detailed information about the chemical properties of their products.
For example, RepRap’s PP Plastic is one of the food-safe filaments available in the market.
Contact time matters
3d printed objects have high porosity, and the cavities between printed layers are ideal places for bacterias to grow. Thus, the extended contact time between cookies and the cookie-cutter can enhance the chance of food contamination.
Fortunately, kitchen tools like cookie cutters or knives don’t have long contact time with food or one’s mouth. So, it’s OK to use them a few times. The ideal choice is to use a PLA printed cookie cutter just for once. Because once you use the tool, a tiny amount of food will seep into it, and the bacterias start to grow.
But if you wanted to use them a few times, make sure that you follow our tips below to make them as safe as possible:
Seal the gaps
Sealing the layer gaps of the PLA printed cookie cutter is one of the important actions you can take to reduce bacteria’s chances of growing. The idea is to use a food-safe sealant or epoxy to plug up the printed cookie cutter’s crevices. In such cases, Polypropylene and polyurethane are great options to use.
Epoxies are easy to find and use. All you need to do is to mix the epoxy resin and its hardener in a specific ratio. You can also find the rate on the catalog for each product.
And to seal the gaps, all you need is your mixed epoxy and a brush.
Wash the cookie cutters correctly
The glass transition temperature of PLA is around 55 to 60°C. It means the PLA printed cookie cutter deforms at this temperature. So, using hot water to wash this print can damage it.
But that doesn’t mean it’s not washable. The alternative way is to wash them with lukewarm water and an anti-bacterial detergent after use. This way, the risk of damaging the part will go away, and its surface becomes clean from bacteria.
Change your extruder
In most situations, using a typical brass nozzle is acceptable. But because most brass hot ends (the most typical option) may contain heavy metals like lead, you can look for food-safe extruders if you want to maximize safety.
Stainless steel is one of the safe materials that has been used in the food industry for centuries. Most knives and other kitchen tools are made of this material. You can also choose a usual stainless steel hot end, which makes it safer.
Lead contamination can become a severe problem if it seeps into your food. However, changing the printer’s nozzle is an easy task and won’t require technical knowledge. You can always change it back after you finish printing kitchen tools. Stainless steel nozzles are way more wear-resistant and provide safer prints.
Changing the hot end isn’t vital if you plan to use a custom cookie cutter for once. However, if you’re serious about printing kitchen tools, this printer upgrade makes much more sense.
How to make it 100% safe?
Up to this point, you may have noticed that it’s challenging to make a 100% food-safe PLA print. There is a significant difference between overall food safety and certified food safe.
For example, wooden chopping boards have very similar properties to printed PLA. They are very porous, and bacterias can grow between their cavities though they are commonly used in the kitchens.
But if we change the question from “Is PLA safe for cookie cutters?” to “Is 3d printing cookie cutters safe?” our objective changes significantly.
Now we can choose the most suitable material. PLA is hard to wash or sterilize, and it’s not as strong as a metal. Other thermoplastics also have the same properties. Nevertheless, we’re not limited to these materials.
By ordering 3d printing services, it’s possible to get a 3d printed metal cookie cutter. This way, the cookie cutter is a proven food-safe kitchen tool that you can use for years!
Casting is another option to use 3d printing technology to create cookie cutters indirectly. This method is more common among jewelry makers though the main idea is the same. First, you need to print the object with a 3d printer and then use it to make a mold.
Applying the casting techniques may seem difficult for beginners. However, many great tutorials like Alec Steele’s channel on youtube make the process much more manageable. While learning the process, make sure to use a metal like aluminum that is safe for the kitchen.
Can we 3d print the cookies?
The concept of 3d printing food may seem like an idea out of a sci-fi movie, but it’s real!
Nowadays, many small to professional manufacturers try to start a new market for food printers. Natural Machines’ Foodini, 3D Systems’ ChefJet, and BeeHex’s Chef3D are food printer examples. These machines can create custom foods out of pasta, chocolate, and even melted sugar grains.
Hence, if you wonder whether 3d printing technology can evolve and make a significant change in the food industry, you should know that it is quite possible! 3d printing food can change the way we serve our food, reduce food waste to zero, and improve health conditions.
On the other hand, the technology of baking 3d printed food hasn’t developed enough yet, so we may have to wait for a while.
In general, there are various methods to 3d print cookie cutters or other kitchenware. It’s up to you to make the process safer or use suitable materials. 3d printing cookie cutters is possible by applying the following rules:
- Use high-quality and food-safe filaments. Cheap and nonstandard materials can cause serious issues.
- Minimize the contact time between the printed tool and food. Using the tools for a long time can increase the chance of contamination.
- Try to wash the tools in the correct way (mentioned above).
- It would be best to use stainless steel nozzles. They eliminate the chances of lead seeping into your cookies.
- It’s wise to fill the layer gaps and cavities with a thin layer of epoxy so that the cookie-cutter will last longer and safer.
There are also indirect methods to use a 3d printer to create reliable kitchenwares like casting or 3d printing online services.