If you have a 3D printer you have probably been tempted or asked to print something that comes in contact with food or a drink. At first thought, the idea seems fine, afterall we use plastic cups, plates, fork and knives in our everyday life. But is it really?
These are some of the things you need to be aware of when 3D printing for use with food.
The process of 3D printing, which is forming an object layer by layer, leaves cavities in the end product (the print). This is a major problem in making food-safe products, as the cavities allow for bacteria growth which is really bad for food safety, especially if it's going to be used more than once!
One solution to this is to coat the 3D print using a food-safe resin, to cover any crevices in the print that would otherwise trap germs and
encourage bacteria growth.
If you are making more than a few copies of the same product, it's probably worth to create a silicone mould using the 3D print, and then cast the end product using an FDA-approved resin. This way you can probably make copies faster as well.
Cleaning the Printer
The print surface of the printer needs to be properly cleaned from any other materials previously printed on the machine! If there is residue from a non-FDA material on the build platform, then that is going to become attached to the food-safe material and contaminate it, so make sure to use a new platform dedicated for food-safe printing or to thoroughly clean your surface.
So now that my surface is clean can I print away? The hotend also needs to be properly cleaned of any other materials that have previously run through it, or any material build-up in the printer's nozzle. It is more appropriate to use a different nozzle and where possible a different hotend dedicated to printing only food-safe products. The nozzle of the printer needs to be made from Stainless Steel, brass nozzles contain lead and pose a thread when they contaminate the end products.
One of the nozzles appropriate for the use of printing food-safe products is the E3D Stainless Steel Nozzle
which is medical grade and food safe.
If you are printing cookie cutters or coffee mugs yourself, make sure to use FDA approved filament. PLA, which is a material made from corn starch, is available in FDA-approved versions without the addition of any other additives. It is much more common for natural color PLA to be food-safe, but some colorants are FDA approved. Make sure to check the spec sheet of the material you are using.
If you are buying cookie cutters or any other print for use with food from a 3D printing service, make sure to ask for the certificate of the material that the cutter has been printed with! You are entitled to know if the cutter you have been sold is safe to use.
So all of this seems quite a lot to get right, especially if someone else is printing the cutters for you.
Should you still buy 3D printed cookie cutters?
It is absolutely fine to use 3D printed cookie cutters, as the printed material comes in contact with the cookie dough for a few seconds and is baked after the cutting process. We would discourage the re-use of the cutters though as washing them does not clean the crevices in the print well enough to stop bacteria growth.
*This is a guideline for 3D printing and using food-safe products, further actions may be required to ensure healthy use of the products.