In this article, Mohou.com will discuss with you the common materials, processes and post-processing of ceramic 3D printing.
Material
△Ceramic materials used for 3D printing can come in many forms, including photoresins and powders.
What is unique about ceramic 3D printing is of course the material. In the art world, the terms “ceramic” and “clay” are often used interchangeably to describe the different materials used to make pottery. Clay is indeed a type of ceramic, but not all ceramics are made of clay. Ceramic is actually made of a variety of materials that harden when heated to high temperatures, a process called firing.
Here are the most commonly used materials in ceramic 3D printing:
●Terracotta is one of the most commonly used ceramics, often used in flower pots, because it is porous and the material is readily available. Its red color comes from the iron oxide that forms when cooking in an oven. Clay can be extruded in an FDM system and is stronger than most clay ceramics.
●Porcelain is a mixture of silica and clay. It comes in three varieties: hard porcelain, soft porcelain and soft porcelain. Hard glaze porcelain is the variety used in fine porcelain and is primarily composed of kaolin mixed with quartz and feldspar. Soft dough contains similar ingredients, but it is cooked at a lower temperature, so the final product is not as hard as hard dough. Today, bone china is made from bone ashes, kaolin clay and feldspar. Porcelain can be manufactured using an FDM extrusion process, or 3D printed as a ceramic photoresist, or powdered and spray bonded with an adhesive.
●Pottery is often finished with mud (a very fluid mixture of clay and water) before firing to improve the texture of the surface and make it waterproof. It is fired in the process but is not vitrified (becomes vitreous), so its surface is rougher than porcelain. Pottery can be made by 3D printing extrusion, and WASP is one of the most famous companies producing ceramic 3D printers.
●Stoneware is a type of non-porous pottery fired at high temperatures. Although it is waterproof, a varnish is often used for cosmetic purposes. Sandstone is most common in 3D printing.
ceramic filament
△In addition to pottery, ceramic filaments are also very suitable for other aesthetic applications, such as this watch case
In addition to directly extruding ceramic materials with special 3D printers, ceramic-based filaments can also be printed on ordinary FDM 3D printers. These filaments are generally composites of adhesives based on polymers and ceramic materials. Like other filaments, they are wound onto a spool, but usually become quite brittle before going through the final heating stage. During the baking process, the polymer is burned off, leaving only the ceramic material, and some filaments require a separate degreasing process to separate the polymer from the ceramic material.
There are several companies on the market that produce ceramic filaments, including Spectrum Filament, LayCeramic, and Zetamix. These filaments tend to be much more expensive than standard pottery materials such as pottery. LayCeramic costs around $140 per kilogram for a diameter of 2.85mm, while Zetamix zirconia-based filament with a diameter of 1.75mm costs around $650 per kilogram.
Ceramic 3D printing
△Wasp Clay Extruder
Today, there are many ways to 3D print ceramics, each with its own advantages and disadvantages. The most cost-effective way to print ceramics is extrusion, but it is also the least precise. Resin printing and binder jetting offer higher levels of precision, but are expensive.
3D printing by extrusion
Clay extrusion-based 3D printing systems are the most common way to create ceramic parts for pottery applications. One of the most popular clay extrusion systems is Wasp’s line of delta clay printers, which can use a pneumatic system to push the clay out of the extrusion nozzle, or a motorized spiral to push the material.
The emergence of ceramic filaments makes it possible to use ordinary FDM machines to print pottery. However, prints will shrink and become smaller due to the degreasing process. For example, LayCeramic filaments shrink by up to a quarter when all the polymer has been burned off. Therefore, more care must be taken when designing the geometry of the pottery so that it remains united during the shrinkage phase, and wall thicknesses are necessary in the design. For thickening, Zetamix recommends that the thickness of its zirconia filament should be designed to be 2mm. When working with these composite materials, larger nozzle diameters are generally preferred, with a 0.6mm nozzle recommended instead of the standard 0.4mm nozzle. The nozzle should be made of hardened steel or steel that can withstand abrasive materials.
Other 3D printing
△A printer with higher precision means a higher price
Ceramics can also be produced using compatible resin 3D printers and binder jetting systems. These machines tend to be used more for technical ceramic applications, but small, highly detailed decorative ceramic components can also be produced using photopolymer systems. Ceramic and polymer blends need to be prepared before printing, such as Formlabs Ceramic Resin and Tethon3D Porcelite. Ceramic resin can make the printing process difficult due to its weight. It is much heavier than most plastics, so it can be difficult to cover the workpiece smoothly and evenly on the workbench.
Binder jet systems can also be used to print ceramic parts, such as Kwambio’s ceramic printer, which uses a powder bed system to produce high-precision ceramic parts. The powdered ceramic is bonded layer by layer with a proprietary adhesive to maintain the shape of the printed part, or “green state,” until it can be glazed and fired. Binderjet ceramics is a very specialized process that requires specialized machinery, so not all binderjet printers can produce it. While it is possible to make pottery using these 3D printing methods, the machines required are very expensive – often starting in the low five figures. These methods are therefore beyond the reach of the average consumer.
Post-processing
△Like traditional pottery, 3D printed pottery must be fired in a kiln
For extrusion systems that print directly onto ceramic materials, the print may dry for one to two weeks, depending on the material used and the size of the part. The dried print is then fired in a kiln, a process called bisque firing. Finally, the glaze is applied and the print is glazed and fired. Ovens are expensive, which is why many people choose to outsource the cooking process. Since the process is often the same as firing any traditional ceramic, a specialized kiln and glaze is usually not necessary.
For ceramic filaments printed with regular FDM printers, post-processing is slightly more complicated. Some filaments need to be degreased before pulling the print. For example, Zetamix’s zirconia filament requires a two-step process after the part is printed. First, the parts had to be placed in a chemical bath of acetone to dissolve the binder, then fired in a powder-filled crucible to thermally remove the remaining binder, with the entire post-processing taking over two days. Before you start using ceramic composite wire, be sure to read the manufacturer’s instructions carefully, as how specific materials are used can vary greatly.
application
△3D printers are now part of the artistic practices of certain ceramists
Ceramic 3D printing has inspired a new generation of artists, sculptors and architects to create beautiful, detailed objects that would have been impossible to achieve using traditional ceramic processes. From pottery to architectural design applications, designers are finding new ways to make ceramics. Ceramic artists such as Jonathon Keep, Kate Blacklock and Emre Can use the 3D printing process to create ceramic pieces for museums and private collections, with stunning and unique results.
In recent years, 3D printers have been used to extrude clay to create unique tiles, artificial reefs and even entire buildings, such as the blue ceramic arches of the historic Dutch city of Delft and the exhibition of 3D printed ceramics from Ceramic Morphologies. all demonstrate the potential of ceramic 3D printing.
Printing service
△A simple method for ceramic 3D printing
As 3D printing and post-processing of ceramics is a rather complex process that requires specialized machinery and knowledge of how the printed parts will react in the kiln, 3D printing services have emerged in the market. If you’re just trying out an idea and don’t want to purchase a full setup yourself, this is definitely the way to go.
Kwambio is a company specializing in ceramic 3D printing services. The company has developed its own ceramic 3D printer based on powder bed technology. She has a guide to designing ceramic pieces on her website. If there are any design issues, their engineers will contact them. before producing the part. You give your opinion. Simply upload a file or sketch to their website and wait to receive your ceramic pieces.
As mentioned above, 3D printers can print anything from kaolin and terracotta to sandstone and earthenware.
Source: 3D Printing Network
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