In July, Solidscape announced the launch of its S500 3D printer, intended for high-precision investment casting applications in virtually any industry sector. This is of huge significance since the company has until now focused on printers for the jewelry sector. Here, Disruptive's news editor Elizabeth Valero speaks to Solidscape’s president and chief executive officer (CEO) Fabio Esposito to gain a better understanding of the S500’s capabilities as well as the company’s motives for launching it.
Elizabeth Valero (EV): First of all, for the benefit of investment casting novices such as myself, can you describe the applications that the S500 can be used for?
Fabio Esposito (FE): The S500 is a high-precision 3D printer that is used to produce wax patterns—also commonly referred to as wax masters—for three applications, namely direct casting, silicon mold making and mold facing.
Direct casting involves using the pattern to create a ceramic mold for casting an end-use metal part. First, the pattern is coated in a ceramic material that hardens and assumes its imprint. This is then placed in a furnace and the pattern burns out to leave the ceramic mold, ready for pouring the hot liquid metal into.
Similarly, silicone mold making involves submerging the pattern in a bath of silicone that solidifies around it. This is placed in a furnace and the pattern burned out to leave the silicon mold. One of the biggest challenges is surface finish; the silicone mold picks up the most minor of surface imperfections from the original pattern. Therefore, it is of critical importance that a silicone mold is produced using a pattern that affords a superior surface finish.
Silicone molds allow you to produce either duplicate patterns for use in the traditional investment casting process or final parts in materials such as urethane. The former involves injecting hot wax into the mold that cools to form an exact replica of your original pattern. This can be repeated as many times as required, for example, if you are looking to produce 100 parts, you inject 100 waxes. These patterns are then attached to a casting tree in preparation for casting altogether. The latter involves injecting other materials such as urethane into the mold. Again, this is repeated depending on the number of parts required.
Mold facing differs from direct metal casting and silicone mold making in that it involves printing the exterior cavity of the part rather than the master model of the part itself. The wax pattern, or exterior cavity, is cast in metal and then waxes are injected into it to produce multiple patterns of the part for casting.
The S500’s build volume is 15 x 15 x 10 cm. It is ideal for small, complex precision parts featuring intricate geometries—a relatively underserved niche that goes across all verticals.
EV: Can you summarize the benefits that the S500 affords over traditional investment casting processes?
FE: It basically allows you to eliminate a step or, in some cases, multiple steps of the traditional processes. The reason being that metal masters are no longer necessary to create ceramic or silicone molds; the patterns produced on the S500 are able to fulfill this purpose. You normally go from the pattern to metal master to ceramic or silicone mold, but using the S500 you can go straight from the pattern to the ceramic or silicon mold, shortening the manufacturing process by days and, in some cases, weeks.
The patterns are extremely stable and accurate, characteristics that are attributable to the materials as much as they are the printing process. These materials, Midas and Melt I, have been developed specifically for industrial use. Midas is a 100 percent castable material, meaning it delivers a clean burnout—so no residues are left inside the mold—and there is no shrinkage or deformation of the pattern. In terms of direct casting, these factors are absolutely crucial, since the ceramic mold has to be perfectly clean and as accurate as it can be. Once the liquid metal has cooled and set in the mold, the part must be ready for use in someone’s body if it is an artificial knee or fitting in an aircraft engine if it is a turbine blade, there cannot be any finishing.
Melt I is a 100 percent dissolvable support material that allows for a completely smooth finish, eliminating the need for any manual refinements. The pattern is immersed in a solution and the support material dissolves in a few minutes, leaving it ready for use, be that in your direct casting, silicon mold making or mold facing application.
EV: The S500 is based on your new Solidjet technology, can you explain how this differs from that of your other printers?
FE: The S500 has been designed for different customers to our printers for the jewelry sector. Their demands are quite different. Increased speed, zero distortion and high-quality interior as well as exterior surface finish are all critical requirements in the industrial market, therefore the objective of Solidjet has been to optimize our drop-on-demand (DOD) printing process.
The materials also play a significant role in addressing these requirements, the support material especially. Other support materials, for example, those used in digital light processing (DLP) and stereolithography (SLA) print processes, have to be clipped from the pattern, often causing damage to it and meaning you have to start over. Then, of course, the pattern requires finishing, or smoothing off, before you can move on to investment casting. Melt-I dissolves away, eliminating the need for clipping and finishing, and thus saving you a considerable amount of time and effort.
Patterns produced on our printers do not in fact need support structures. Other 3D printing technologies require support structures because they have the pattern rising out of a vat of photopolymer resin and gravity obviously has to be accounted for. The support structures must be added to designs in order for patterns to be printed. This is especially challenging if the patterns feature overhangs, undercuts and complex geometries.
Our technology deposits microscopic drops of material precisely and accurately, layer upon layer. The support material is simply used to enrobe and help build the pattern, allowing you to build overhangs, undercuts and complex geometries without fiddly support structures.
EV: I understand your 3D printing process is different to that of competitors’ in terms of being both additive and subtractive, how does this work and what are the benefits?
FE: Our printing process is pretty unique in that after each layer of material is deposited, a rotating milling blade is run across the top to shave off any unevenness and make it perfectly flat. This so-called subtractive element ensures that the finished pattern is free from any imperfections.
I often use the fairytale ‘The princess and the Pea’ as a means of explaining this. With other technologies, if one layer of material has an imperfection, this is going to be carried through to the layer above it, then the layer above that and so on, resulting in the pattern becoming increasingly distorted right up to the top and final layer. Our two-step process guarantees there is no chance of this happening.
EV: Is it possible for you to share your beta customers’ experience of the S500?
FE: I cannot reveal the names of our beta customers, but one is a USA-based company that produces waveguides for use in microwaves and other electronic equipment. These are hollowed rectangular parts, around one-and-a-half inches in length, that have this twist. The inside of the part features these tiny pyramid-like structures that serve to transmit or guide electromagnetic waves, therefore the quality of the interior surface finish has to be ‘as good as’ the exterior surface finish.
The customer had been using one of our jewelry printers and is finding the S500 to be much faster, more reliable and capable of achieving a superior internal surface finish. They say ours is the only technology available for producing parts to the standards required, particularly in terms of the accuracy it affords in putting down the layers of material.
EV: Finally, can you outline Solidscape’s strategy moving forward and share your predictions for the future of manufacturing?
FE: Solidscape has brought a lot of benefits to the jewelry market over the years and our belief is that those benefits can be brought to other vertical markets. Specifically, we have helped our jewelry customers transition from mass production to mass customization and are now looking to do the same with manufacturers in markets such as aerospace, automotive and medical.
I believe mass customization is the future, that the focus on mass production is going to become less and less over the next 10 years. There are plenty of buzzwords flying around, such as industry 4.0 and the internet of things, but it remains to be seen if these come to fruition and stay. They do, however, signal to us that there is a growing need for customization.
The industrial revolution brought us to mass production, driving costs down on large quantities of the same item. Today, the drive is towards mass customization, so using tools such as CAD, 3D printing and project lifecycle management (PLM) to drive costs down on one-off items.