Charles Hull, later the co-founder of 3D Systems, invents stereolithography, a printing process that enables a tangible 3D object to be created from digital data. The technology is used to create a 3D model from a picture and allows users to test a design before investing in a larger manufacturing program.
1) A laser source sends a laser beam to solidify the material.
2) The elevator raises and lowers the platform to help lay the layers.
3) The vat contains the material used to create the 3D object.
4) The 3D object is created as parts are layered on top of each other.
5) Advanced 3D printers use one or more materials, including plastic, resin, titanium, polymers and even gold and silver.
1990s - Different Technologies Emerge
Special application of plastic extrusion, developed in 1988 by S. Scott Crump and commercialized by his company Stratasys, which marketed its first FDM(fused deposition modeling) machine in 1992.
That same year, startup DTM produced the world’s first selective laser sintering (SLS) machine—which shoots a laser at a powder instead of a liquid.
In 1993, Royden C. Sanders builds a PC-based 3D wax printers for rapid prototyping and creating master molds used for investment casting. Later, the company will become known as SolidScape.
In 1995 the Fraunhofer Institute develops the selective laser melting process for direct metal printing.
The Future of 3D Printing in Jewelry - Direct Metal 3D Printing
How does it work?
CAD files are prepared for printing, by adding support structures
Focused laser beam melts the powder layer by layer
Models are excavated from the powder
Supports are broken off
Finishing
Advantages
Unattended operation over night/weekend
Production of jewelry parts with almost no limitation in geometry/complexity
Reduction of manufacturing steps > from CAD to metal parts in one step
High density, less porosity than casting
High accuracy and detail (micropavee)
Outlook
New developments in powder manufacturing, such as the AU series atomizers from Blue Power, will give manufacturers more flexibility and autonomy and allow researchers to experiment with different alloys and particle sizes for improved surface finish.
Additive Manufacturing by ASTM (American Society for Testing and Materials): “Process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as traditional machining”
Naming:
Rapid Prototyping: This term was used in the beginning of the professional use of the technology because the main application was the manufacturing of prototypes, mock ups and sample parts.
Advantages:
Design complexity and freedom: The advent of 3D printing has seen a proliferation of products (designed in digital environments), which involve levels of complexity that simply could not be produced physically in any other way. While this advantage has been taken up by designers and artists to impressive visual effect, it has also made a significant impact on industrial applications, whereby applications are being developed to materialize complex components that are proving to be both lighter and stronger than their predecessors.
Speed: You can create complex parts within hours , with limited human resources. Only machine operator is needed for loading the data and the powder material, start the process and finally for the finishing. During the manufacturing process no operator is needed.
Customization: 3D printing processes allow for mass customization — the ability to personalize products
according to individual needs and requirements. Even within the same build chamber, the nature of 3D printing means that numerous products can be manufactured at the same time according to the end-users requirements at no additional process cost.
Sustainable / Environmentally Friendly: 3D printing is also emerging as an energy-efficient technology that can provide environmental efficiencies in terms of both the manufacturing process itself, utilizing up to 90% of standard materials, and, therefore, creating less waste, but also throughout an additively manufactured product’s operating life, by way of lighter and stronger design that imposes a reduced carbon footprint compared with traditionally manufactured products.
No storage cost: Since 3D printers can “print” products as and when needed, and does not cost
more than mass manufacturing, no expense on storage of goods is required.
Increased employment opportunities: Widespread use of 3D printing technology will increase the demand for designers and technicians to operate 3D printers and create blueprints for products.
Jewelry Industry
was one of the first to realize the potential of 3D printing. With the help of Computer Aided Designing (CAD),
manufacturers are able to 3D print master patterns for jewelry, which are then cast in precious metal to create intricate art pieces. 3D printing has given designers the liberty to experiment with complex designs and abstract patterns to create dazzling jewelry.
The major benefits of the technology includes easy customization for on-request, unique designs, handling of more complex and intricate designs efficiently and minimizing or eliminating countless mold storage.
Figure 1: Lingual braces are mounted on the inner surface of the tooth to conceal them.
In the past, the path to perfectly aligned teeth meant a smile marred by a mouthful of metal brackets and wire. For many adults, the stigma discouraged them from undergoing orthodontic care. A solution to this problem is to hide the braces on the inside of the teeth. However, this simple idea poses unique challenges and difficulties.
T.O.P. Service für Lingualtechnik GmbH (Bad Essen, Germany) overcame the challenges of lingual orthodontic treatment and introduced its Incognito system. The company’s unique approach to positioning, optimizing results and improving patient comfort relies heavily on custom appliances produced with rapid manufacturing technology.
Hidden Braces
Lingual (tongue side) orthodontic appliances [Figure 1] are mounted on the inner surfaces of the teeth. Like the labial (lip side) appliances, the brackets are bonded to the tooth surface, and an archwire connects the brackets. Unlike labial appliances, lingual braces require precise bracket positioning and high precision in the brackets’ archwire slots. Additionally, since the appliance is on the inside, the lingual brackets must have a smaller profile so that they do not cause discomfort or speech impairment.
Figure 2: Custom lingual brackets have a profile of 2 mm (0.08 in.) and an archwire slot guaranteed at 5 micron (0.00016 in.) precision.
T.O.P. Service’s early success arose from its innovations in bracket placement. The Transfer Optimized Positioning system improved positional accuracy and decreased the patient’s time in the orthodontist’s chair. However, T.O.P. Service determined that it needed further improvements to decrease treatment times, optimize results and diminish patient discomfort. In 2001, T.O.P. Service reinvented its processes and introduced custom lingual brackets. Designed patient-by-patient and tooth-by-tooth, these brackets deliver precision and control for improved results. The small profile also improves patient comfort by minimizing tongue irritation.
Custom Lingual Brackets
Each orthodontic appliance requires up to 16 brackets. T.O.P. Service begins with a malocclusion model, which is used to digitally design brackets, and finishes with investment cast brackets made from dental gold. The lingual brackets [Figure 2] measure 5 x 3 x 2 mm (0.200 x 0.118 x 0.079 inch), and they have only a 0.4 mm (0.016 inch) wall thickness. Production of these small, detailed brackets is complicated by the archwire slot. Measuring only 0.46 x 0.64 mm (0.018 x 0.025 inch), the archwire slot must be extremely precise. According to Ralf
Figure 3: T.O.P. Service now operates 8 T66 Benchtop™ systems
Paehl, Dipl.-Ing, head of research and development, “To impart multidirectional forces to the bracket, the rectangular slot must hold the archwire, which can be round or rectangular, without any slippage.” This precision is so critical that T.O.P. Service guarantees ±5 micron (0.0002 inch) slot tolerances for each of the custom brackets that it makes.
In its reinvention of the process, T.O.P. Service faced the challenge of developing a method to rapidly manufacture the high-precision, fully customized brackets. After evaluating all possibilities, the company selected a Solidscape ModelMaker™ II system for creation of investment casting patterns. According to Paehl, the key criteria in the evaluation were resolution, surface finish, castability, and precision. Solidscape offered the best three-dimensional printing technologies and 3D printer software of all the 3D printer companies they reviewed.
Dr. Dirk Wiechmann, CEO and founder, stated, “The biggest advantage of the Solidscape technology is the precision of the layer thickness. To yield the ±5 micron precision, our only other option would be to wire EDM each bracket slot.”
Over the past four years, the company has expanded its operations to include eight Solidscape T66 Benchtop™ systems [Figure 3], which enables it to deliver 150 custom-made orthodontic appliances each week. Solidscape rapid prototyping machines have some of the best 3D printer reviews in the industry and advanced technologies that make them one of the most sought-after 3D printer manufacturers.
Figure 4: White light scanning captures a digital representation of the malocclusion model.
The Manufacturing Process
Production of lingual appliances begins with malocclusion models of the patient’s teeth. These models are cast from impressions taken by the orthodontist. One model becomes the setup after it is manipulated to align the teeth to the target positions. This setup is reverse engineered with a white light scanner [Figure 4] to create a digital model that is loaded into T.O.P. Service’s 3D printer software. Selecting from a library of brackets, T.O.P. Service technicians position the brackets and adjust their features for optimal results [Figure 5]. The bracket design is output as an STL file for building patterns for investment casting
The T66 Benchtop, which can build with 13 micron (0.0005 inch) layers, constructs the bracket patterns [Figure 6] with proprietary thermoplastic ink jetting technology. The thermoplastic, which has wax-like properties, is deposited as small droplets. For precise layer thickness and flatness, a cutter mills the horizontal plane. When complete, the patterns are post processed by dissolving the support material and wiping off any debris.
Figure 5: Custom lingual brackets are designed and positioned with CAD software.
The next step is to attach cast pipes to the patterns and assemble them to make the casting tree. The tree is then embedded in a “speed plaster” to create the investment casting shell. The shell is heated to 690® C (1,274® F) to burn out the patterns and then dental gold is cast into the investment. This process, which is computer controlled, takes only two hours. Paehl stated that he has 100 percent casting yield. ”Short duration, low temperature burnout and no residual ash are critical in our process. The Solidscape patterns give us all three,” said Paehl. After cooling, the shell is broken away to yield the metal brackets [Figure 7]. The runners (cast pipes) are then removed, and the brackets are tumbled in a polishing compound to smooth the surfaces.
Figure 6: Bracket patterns for investment casting being constructed in a T66 Benchtop.
To complete the process, the brackets are mounted to the malocclusion model [Figure 8], and a transfer tray, which captures the brackets, is cast. T.O.P. Service’s rapid manufacturing process, from treatment planning to shipment of the lingual appliance, takes only 10 to 15 days.
Continuous Improvement
In one year, T.O.P. Service has increased its production volume by 400%. Some of the increase is from the addition of more T66 Benchtop systems, more operating hours, and more technicians, but much of the throughput gain has resulted from improvements in Solidscape’s three-dimensional printing technology, process, and pattern material.
Figure 7: Investment cast lingual brackets after shell removal.
The most recent developments for the T66 Benchtop and the introduction of the InduraCast™ material have increased the company’s pattern production by 33 percent. Since T.O.P. Service runs their machines around the clock, this speed improvement has increased throughput without additional capital expenditures.
Following the adoption of InduraCast, T.O.P. Service’s scrape rate for patterns has plummeted to a negligible amount. “The material has improved the quality of the bracket patterns and increased its durability. With walls of just 0.4 mm (0.016 inch), our technicians used to damage the patterns while preparing them for investment casting. Now, we have a pattern yield rate of 99.0 to 99.8 percent,” said Paehl. Since the investment casting yield rate is 100 percent, T.O.P. Service has a net bracket casting yield that exceeds 99 custom brackets for every hundred pattern. This is nearly a 20 percent improvement in casting throughput.
Figure 8: Custom lingual brackets bonded to malocclusion model prior to casting of transfer tray.
Combined, the improvements have delivered a 55 percent increase in output from each of the company’s eight T66 Benchtop systems. This productivity gain has improved T.O.P. Service’s profitability by increasing capacity and decreasing staffing demands. “Prior to the latest developments, I had planned to add four casting technicians. Now I find that I only need two new employees to keep up with the demand,” said Paehl.
Dr. Wiechmann stated, “We are using the Solidscape systems for mass production, and we find that they are production quality devices.” Yet, the company continuously seeks to improve its process. “We are always looking for new and better ways to make our product, but when it comes to rapid manufacturing the brackets, we always come back to Solidscape. No other technology has demonstrated the ability to produce the precision and surface finish that we need with the castability that we demand,” stated Dr. Wiechmann.
Dr. Wiechmann expects substantial growth in the coming years. But now that his company has overcome the challenge of lingual orthodontic appliances, TOP Service faces a new challenge, gaining acceptance. “The potential market is huge. Our biggest hurdle is to convince the orthodontists that Incognito is not a difficult treatment process and that it is a better solution,” commented Dr. Wiechmann.
Author information
Todd Grimm, president of T. A. Grimm & Associates, Inc. (Edgewood, Kentucky), is a rapid prototyping consultant, writer and speaker. He is the author of “User’s Guide to Rapid Prototyping.”
Things can move very quickly in the multi-million dollar world. Just earlier this week, one of the biggest deals in 3D printing failed after U.S. conglomerate General Electric (GE) refused to upgrade its $745 million offer for German metal 3D printer manufacturer SLM Solutions. And now, just days later, GE confirmed its intention to become a major player in the metal 3D printing sector by purchasing another German 3D printer specialist, Concept Laser, for $599 million (549 million euros).
It’s just the latest chapter in a crazy week for GE. Back in September, GE sent ripples through the 3D printing market by making unexpected offer of a combined $1.4 billion to take over two of the driving forces behind metal 3D printing, Arcam AB and SLM Solutions. While receiving a lot of positive signals from within the 3D printing community, both deals ran into shareholder problems.
While the executive boards of both companies were onboard with the takeover, in both cases GE’s excellent offer (featuring a significant premium) failed to convince 75 percent of the shareholders, the minimum acceptance threshold for a take-over. While the Arcam offer has since been extended, the SLM Solutions deal was marred by opposition from the Elliot Management hedge fund of billionaire investor Paul Singer (who owns 20 percent of SLM shares). While GE could’ve raised their offer or extended the tendering period, GE Chief Financial Officer Jeff Bornstein said earlier this week that they were not planning to do so, saying that “we have other options.”
While Singer has a reputation for trying to squeeze extra money out of takeover deals through last minute opposition, he will have doubtlessly been disappointed to find that GE stuck to its original $745 million offer. As a result, SLM shares went down 5.7 percent in after-market trading in Frankfurt. But as it turns out, GE really did have another option on the table. Fast forward a few days, and GE just revealed that they have agreed buy privately held German 3D printing firm Concept Laser for $599 million. As part of the deal, GE will be initially buying 75 percent of the Lichtenfels-based Concept Laser.
Concept Laser itself is an equally appealing metal 3D printing company, with a special focus on the aerospace, medical and dental industries. Currently employing more than 200 staff members, the company has been particularly praised for its patented LaserCUSING layer construction technology and its top-of-the-line industrial grade machines. What’s more, they have not at all suffered from a supposedly stagnating 3D printing market, as 2015 was the best year in their history in terms of sales, with 2016 likely to break that record. Back in August, they revealed an 88 percent increase in sales over early 2016, when compared to the same period in 2015.
But the company was also looking to sell, and now found the deal they were looking for. GE, which has previously spent about $1.5 billion on metal 3D printing research, is already planning to invest ‘significantly’ in Concept Laser and would turn its Lichtenfels HQ in a new German GE center. Co-founder Frank Herzog will stay on as chief executive. “We are delighted to achieve the strategic cornerstone in our additive strategy by announcing today our acquisition of Concept Laser,” GE Aviation chief David Joyce said.
At the same time, the deal for ARCAM has also received a boost. While that deal suffered from similar sharehol
Figure 2: Custom lingual brackets have a profile of 2 mm (0.08 in.) and an archwire slot guaranteed at 5 micron (0.00016 in.) precision.
Figure 3: T.O.P. Service now operates 8 T66 Benchtop™ systems
Figure 4: White light scanning captures a digital representation of the malocclusion model.
Figure 5: Custom lingual brackets are designed and positioned with CAD software.
Figure 6: Bracket patterns for investment casting being constructed in a T66 Benchtop.
Figure 7: Investment cast lingual brackets after shell removal.
Figure 8: Custom lingual brackets bonded to malocclusion model prior to casting of transfer tray.
