Recently, in a new paper entitled “3D Food Printing Technology Review“, a group of researchers outlined various methods of 3D printing food, and their uses, advantages and disadvantages. They evaluate each technology based on print suitability, productivity, material characteristics, effect parameters, and printer mechanisms.
The first method the researchers studied was 3D printing based on extrusion technology, which is similar to fused deposition molding (FDM) except that the starting material can be solid or pasty. Examples of foods printed this way are batter, meat sauce and cheese. Researchers point to several other studies using this method, including those focused on 3D printed sugar cookies, lemon juice gel, surimi gel, and chocolate. The results collected from these studies include:
- Nozzle moving speed and extrusion speed affect the quality of 3D food printing
- Extruder components should be as rigid as possible, especially for chocolate 3D printing
- 3D printing of chocolate requires effective active cooling system
According to researchers, the advantages of extrusion-based 3D printing are the low cost of entry-level printers, the variety of raw materials available, and ease of customization. Disadvantages include low accuracy and long build times.
Inkjet printers typically print with low-viscosity liquids, so they are usually not used for 3D printing complex food structures, but instead are downgraded to things such as surface filling or decorations on biscuits, cakes or pizza. Ingredients include chocolate, batter, syrup, pate, cheese, jam and gel.
“This process usually uses a thermal or piezoelectric head,” the researchers said. “In a thermal inkjet printer, the printhead is electrically heated to generate pressure pulses and eject droplets from the nozzle. There are two types of inkjet printing methods: continuous inkjet printing and on-demand inkjet printing.
The advantages of inkjet printing include high resolution, precision and a variety of materials. Disadvantages include the exquisite 3D printing capabilities that can be damaged by post-processing.
Finally, the researchers discussed adhesive spray. This involves the use of a binder to selectively adhere the powder layers.
“For the adhesive spray process, the properties of powder materials and adhesives are important to the successful manufacture of parts,” the researchers said. “The adhesive must be a suitable low viscosity, where surface tension and ink density are suitable properties to prevent nozzle diffusion.”
Advantages of adhesive spraying include high production speeds and the automatic inclusion of support structures in layer manufacturing. Disadvantages include a rough or granular appearance and the need for post-treatment to remove moisture or improve the strength of the printed food.
Authors of the paper include Paphakorn Pitayachaval, Nattawut Sanklong, and Anantapoom Thongrak from Suranaree University of Technology, Thailand.
Source: 3D Printing Online