3D printing is any of various processes in which material is joined or solidified under computer control to create a three-dimensional object, with material being added together (such as liquid molecules or powder grains being fused together). 3D printing is used in both rapid prototyping and additive manufacturing. Product can be of almost any shape or geometry as show in figure 1 and typically are produced using digital model data from a 3D model or another electronic data source such as an Additive Manufacturing File (AMF) file (usually in sequential layers).
Figure 1: 3D printer and the product.
There are many different technologies, like stereolithography (SLA) or fused deposit modeling (FDM). Thus, unlike material removed from a stock in the conventional machining process, 3D printing or Additive Manufacturing builds a three-dimensional object from computer-aided design (CAD) model or AMF file, usually by successively adding material layer by layer. The term “3D printing” originally referred to a process that deposits a binder material onto a powder bed with inkjet printer heads layer by layer. More recently, the term is being used in popular vernacular to encompass a wider variety of additive manufacturing techniques. There are many type of material can be used in 3D printer such as polymer, metal and ceramic. Within the field of 3D printing and additive manufacturing, ceramic materials are still playing catch up as compared with polymer and metal material categories. Ceramic materials can categorize in four ways such as: structural ceramics, refractory ceramics, white wares, and technical ceramics. Therefore, ceramic material for 3D printer discuss as below.
Advantages of 3D printer
One of the main advantages of additive manufacture is the speed at which parts can be produced compared to traditional manufacturing methods. Complex designs can be uploaded from a CAD model and printed in a few hours. The advantage of this is the rapid verification and development of design ideas. Where in the past it may have taken days or even weeks to receive a prototype, additive manufacturing places a model in the hands of the designer within a few hours. While the more industrial additive manufacturing machines take longer to print and post-process a part, the ability to produce functional end parts at low to mid volumes offers a huge time-saving advantage when compared to traditional manufacturing techniques (often the lead time on an injection molding die alone can be weeks).
Besides, 3D printer lesser steps than traditional manufacturing. A designer need to concern about how to manufacture a complex part as efficiently as possible. Most parts require a large number of manufacturing steps to be produce by traditional technologies. The order these steps occur affects the quality and manufacturability of the design. Similarly to additive manufacturing, the process begins with a CAD model. Once the design is finalized, fabrication begins with first cutting the steel profiles to size. The profiles are then clamped into position and welded one at a time to form the bracket. Sometimes a custom jig will need to be made up to ensure all components are correctly aligned. The welds are then polished to give a good surface finish. Next holes are drilled so the bracket can be mounted on the wall. Finally, the bracket is sandblasted, primed and painted to improve its appearance.
Moreover, 3D printer can manufacture higher complexity and design freedom as compare traditional manufacturing. The restrictions imposed by traditional manufacturing on what can be made are generally not relevant for additive manufacturing. Since components are constructed one layer at a time, design requirements such as draft angles, undercuts and tool access do not apply, when designing parts to be 3D printed. While there are some restrictions on the minimum size features that can be accurately printed, most of the limitations of additive manufacturing center around how to optimally orientate a print to reduce support dependency and the likelihood of print failure. This gives designers a large amount of design freedom and enables the easy creation of very complex geometries.
Limitation of ceramic material in 3D printer
Ceramic products from 3D printing are completely waterproof and can resist extreme temperatures of up to 500 °C (932 °F). Its durability when it comes to temperature makes ceramic a great choice for personalized tableware (cups, plates, bowls, etc.) or artistic creations, but it can also be used for more scientific purposes that require an object that can withstand high temperatures. Objects 3D printed in ceramic have the same qualities as ceramic objects created by traditional means. It is important that the object avoids intense shock, otherwise running the risk it will break. However, there are some design limitation as below.
First, the maximum dimension of product is limited by the physical size of the printer itself and by the glazing process. Products must thus respect a minimum and maximum size on a global scale (the sum of the object’s three dimensions, X + Y + Z) as well as minimum fill volume to be printed in ceramic. The minimum fill volume represents the amount of space products must occupy within a printing batch. If product does not take up at least 5% of the printer’s total batch size it will be too small and fragile to print effectively.
Second, the other limitation is minimum thickness and geometry are needed. The walls of product must be thick enough to withstand the printing, glazing and kilning processes. Recommended making product with the restrictions particular to ceramic in mind for the most success with print. Also note that the corners which are too sharp may be cut off in the printing process. It is thus important to respect the minimum bevel radius of product. Particular care must be given to the geometry of product’ design and the most stressed parts must be thicken as show in Figure 2 below.
Figure 2: Suitable design for 3D printer.
Other than that, etching and embossing depths are limited in ceramic mater. Ceramic is not the best material choice for designs with very specific details as the glazing and kilning processes do not allow for it. The width of engraved details should be at least as important as their depth so that the glaze does not clog the pattern.