"Viewpoint" is a column authored by Terry Wohlers for Time-Compression Technologies. 
This column was published in the March/April 2008 issue. 

Terry Wohlers and Tim Gornet

Additive fabrication (AF) technology emerged in 1987 with stereolithography (SL) from 3D Systems (Rock Hill, SC), a process that solidifies thin layers of ultraviolet (UV) light-sensitive liquid polymer using a laser. The SLA-1, the first commercially available additive process in the world, was the precursor of the once popular SLA 250 machine. (SLA stands for StereoLithography Apparatus.) The Viper SLA product from 3D Systems has since replaced the SLA 250.

In 1988, 3D Systems and Ciba-Geigy partnered in SL material development and commercialized the first generation of acrylate resins. DuPont’s Somos stereolithography machine and materials were developed the same year. Loctite also entered the SL resin business in the late 1980s, but remained in the industry only until 1993.

After 3D Systems commercialized SL in the U.S., Japan’s NTT Data CMET and Sony/D-MEC commercialized their versions of stereolithography in 1988 and 1989, respectively. NTT Data CMET (now a part of Teijin Seiki, a subsidiary of Nabtesco) calls its system Solid Object Ultraviolet Plotter (SOUP), while Sony/D-MEC (now D-MEC) calls its product Solid Creation System (SCS). In 1988, Asahi Denka Kogyo introduced the first epoxy resin for the CMET SL machine. The following year, Japan Synthetic Rubber (now JSR Corp.) and DSM Desotech began to offer resins for D-MEC machines.

In 1990, Electro Optical Systems (EOS) of Germany sold its first Stereos stereolithography system and Quadrax (Portsmouth, RI) introduced the Mark 1000 stereolithography system, which used visible light resin. The next year, Imperial Chemical Industries (London, England) introduced a visible light resin product for use with the Mark 1000. However, ICI stopped selling it about one year later when Quadrax dissolved due to legal conflicts with 3D Systems.

Introduction of Non-SL Systems
In 1991, three additive technologies were commercialized, including Fused Deposition Modeling (FDM) from Stratasys (Eden Prairie, MN), Solid Ground Curing (SGC) from Cubital and Laminated Object Manufacturing (LOM) from Helisys. FDM extrudes thermoplastic materials in filament form to produce parts layer by layer. SGC, which also worked with UV-sensitive liquid polymer, solidified full layers in one pass by flooding UV light through masks created with electrostatic toner on a glass plate. LOM bonds and cuts sheet material using a digitally guided laser. Cubital and Helisys are no longer in business.

Selective Laser Sintering (SLS) from DTM (now a part of 3D Systems) and the Soliform stereolithography system from Teijin Seiki (now a part of CMET Inc.) became available in 1992. Using heat from a laser, SLS fuses powdered materials. The Soliform technology was originally developed by DuPont under the Somos name and was subsequently licensed to Teijin Seiki for exclusive distribution rights in parts of East Asia. Also in 1992, Allied Signal introduced vinylether Exactomer resin products for SL.

In 1993, Soligen (Santa Ana, CA) commercialized Direct Shell Production Casting (DSPC), and Denken (Japan) introduced a stereolithography system that used a solid-state laser. Using an inkjet mechanism, DSPC deposits liquid binder onto ceramic powder to form shells for use in the investment-casting process. The Massachusetts Institute of Technology (MIT) invented and patented the process that Soligen used. The company ceased operations in January 2006. Denken’s stereolithography system was interesting because it was one of the first to fit on a bench top and was introduced at a low price.

Also in 1993, 3D Systems and Ciba commercialized its first epoxy resin product. At around the same time, the QuickCast build style was introduced. This is a method of producing investment-casting patterns that are mostly hollow, making it possible to burn them out without fracturing the ceramic shell.

1994 was a year of many new AF system introductions. ModelMaker from Solidscape (Merrimack, NH) (then called Sanders Prototype) became available, as did new systems from Japanese and European companies. ModelMaker deposits wax materials using an inkjet print head. One of the new Japanese systems was a small stereolithography machine from Meiko targeted mainly at the makers of jewelry. (Meiko ended its SL business in 2006.) Meanwhile, Kira Corp. commercialized Japan’s first non-stereolithography system, the Solid Center. Referred to as the first plain paper printer, it uses a standard laser printer engine, toner, and an x-y plotter and knife to produce wood-like models by paper lamination.

Also in 1994, Fockele & Schwarze (F&S) of Germany introduced a stereolithography machine, but on a limited basis. The German company EOS commercialized a machine called EOSINT based on laser-sintering technology. Japan’s Ushio (now called Unirapid Inc.) sold its first stereolithography machine in 1995.

Introduction of 3D Printers
In 1996, Stratasys introduced its Genisys product, an extrusion process similar to FDM, but based on an additive process developed at IBM’s Watson Research Center. After eight years of selling stereolithography systems, 3D Systems sold its first 3D printer (Actua 2100) the same year, using a technology that deposits wax material layer by layer using an inkjet mechanism. Also in 1996, Z Corp. (Burlington, MA) launched its Z402 3D printer for concept modeling. Based on MIT’s inkjet printing (3DP) technology, the Z402 produces models using starch- and plaster-based powder materials and a water-based liquid binder. The same year, Schroff Development (Mission, KS) began to sell its semi-automated paper lamination system for under $10,000.

Personal Modeler 2100 from BPM Technology was sold commercially in 1996. The Ballistic Particle Manufacturing (BPM) process deposited wax materials using an inkjet print head. The company ceased operations in October 1997. Also in 1996, Aaroflex commercialized DuPont’s Somos stereolithography technology in the U.S. Kinergy of Singapore also began to sell its Zippy paper lamination systems, which functioned similarly to the LOM process.

AeroMet was founded in 1997 as a subsidiary of MTS Systems Corp. (Eden Prairie, MN). The company developed Laser Additive Manufacturing (LAM) that used a high-power laser and powdered titanium alloys. Until it shut down in December 2005, AeroMet manufactured parts for the aerospace industry as a service provider. Also in 1997, Ciba purchased the Exactomer resin business from Allied Signal.

In 1998, Beijing Yinhua Laser Rapid Prototypes Making & Mould Technology Co., Ltd. stepped up the promotion of its products. Since 1996, Tsinghua University in Beijing has offered technologies similar to FDM and other additive processes. The same year, Autostrade (Oita-City, Japan) introduced its E-DARTS stereolithography system to companies in Japan for $25,000. Optomec (Albuquerque, NM) also commercialized its Laser Engineered Net Shaping (LENS) metal powder system based on technology developed at Sandia National Labs.

In March 1999, 3D Systems introduced a faster and less expensive version of Actua 2100 called ThermoJet. A month earlier, the company began to sell its SLA 7000 product for $800,000, the most expensive plastic-based additive system on the market at the time. In April 1999, Extrude Hone (Irwin, PA) (now Ex One) installed its first ProMetal RTS-300 machine for building metal parts at Motorola. The system is based on MIT’s 3DP inkjet printing technology. Fockele & Schwarze of Germany introduced its steel powder-based selective laser-melting system, developed in cooperation with the Fraunhofer Institute for Laser Technology.

This same year, Röders began to sell its Controlled Metal Buildup (CMB) machine, based largely on technology developed at the Fraunhofer Institute for Production Technology. DSM also purchased the Somos business from DuPont.

In January 2000, Helisys announced that Toyoda Machine Works of Japan would manufacture and sell LOM systems in Japan. In June, Toyoda showed its first machine based on LOM technology at a large exhibition in Tokyo. The same month, Sanders Design International (Wilton, NH) announced the development of a machine named Rapid ToolMaker (RTM). Also in January, Sanders Design International announced that it had licensed the RTM technology to the German company Buss Modeling Technology (BMT), formerly Buss Müller Technology, with the intent of manufacturing and selling it in Europe. Around the same time, BMT announced that it would manufacture and sell a color 3D printer based on powder and binder technology developed by Aad van der Geest of the Netherlands.

New Generation Machines
April 2000 was full of new introductions. Objet Geometries of Israel announced Quadra, a 3D inkjet printer that deposits and hardens photopolymer using 1,536 nozzles and a UV light source. Sanders Prototype (Merrimack, NH) (now Solidscape) introduced PatternMaster, a machine designed to produce precision wax patterns. Precision Optical Manufacturing (POM) (Auburn Hills, MI) announced direct metal deposition (DMD), a laser-cladding process that produces and repairs parts using powdered metal. POM began system sales in early 2002 and continues to offer DMD as a service. Z Corp. introduced its Z402C machine, the world’s first commercially available multiple color 3D printer.

In July 2000, Stratasys introduced Prodigy, a machine that produces parts in ABS plastic using FDM technology. In October, Sanders Prototype, Inc. changed its name to Solidscape, Inc. to avoid confusion with Sanders Design International. In November 2000, Helisys closed after selling more than 375 systems worldwide over nine years. The same month, Helisys founder and LOM inventor Michael Feygin announced the formation of Cubic Technologies (Torrance, CA). The new company absorbed most of the assets of Helisys and has been manufacturing, selling and servicing LOM machines. Also in November, Teijin Seiki announced that it would acquire the CMET SL technology from NTT Data. By March 2001, the acquisition was complete and the manufacturer changed its name to CMET, Inc.

In 2001, Solidimension of Israel quietly introduced its desktop machine, a technology that laminates thin sheets of PVC plastic. The company was slow to ship machines to customers and to beta test sites, and did not sell machines in 2002 as planned. Finally, in 2004, it sold its first machines to companies in Japan. Also in 2001, Aaroflex and Cubital quietly disappeared from the industry. Israel-based Cubital was one of the first companies to commercialize an additive process and sold 33 systems over eight years.

In February 2001, 3D Systems acquired OptoForm, a French company that developed a stereolithography method of using non-liquid photocurable materials. The OptoForm technology is capable of using ceramics, metals and various composite materials in the form of pastes.

In March 2001, Objet Geometries began to ship a beta version of its Quadra 3D printer. In May 2001, Solidica disclosed technical details on its Ultrasonic Consolidation machine, and began to ship machines to beta customers in late 2001 and early 2002. The technology combines ultrasonic welding and CNC machining to produce aluminum parts. In September 2001, Stratasys began the commercial shipment of its FDM Titan, a machine capable of producing parts in polycarbonate, ABS, polyphenylsulfone and a polycarbonate-ABS blend.

In August 2001, 3D Systems completed its acquisition of DTM, which sparked an intense investigation by the Antitrust Division of the U.S. Department of Justice. In September 2001, 3D Systems acquired RPC Ltd., a small stereolithography resin producer based in Switzerland. This occurred on the heels of Huntsman (The Woodlands, TX) (then Vantico and formerly Ciba) severing its long-term distribution relationship with 3D Systems.

A lot happened at EuroMold 2001. EnvisionTEC of Germany showed its Perfactory machine, which uses acrylate photopolymer and Digital Light Processing (DLP) technology from Texas Instruments to harden an entire layer at once. Z Corp. also introduced its Z810, a system that prints parts in a 500 x 600 x 400 mm (20 x 24 x 16 inch) build volume using 1,800 jets from six HP print heads.

Objet Geometries introduced its QuadraTempo product, an improved version of its Quadra machine. EOS announced its DirectSteel 20-V1 product, a steel-based powder consisting of particles 20 microns (0.0008 inch) in size. The powder is used to produce metal parts in layers that are 20 microns (0.0008 inch) in thickness. Around the same time, the company introduced its EOSINT 380, a laser-sintering machine that offered speed improvements.

Concept Laser GmbH, a Hofmann company in Germany, surprised many at EuroMold with a new system that combines laser sintering, laser marking and laser machining. The machine uses an yttrium-aluminum-garnet (YAG) laser and stainless steel powder to produce fully dense parts. Shanghai Union Technology Co., Ltd. (also known as Uniontech) of Shanghai, China, began to sell its stereolithography machines in China.

In 2001, Generis GmbH of Germany commercialized its large GS 1500 system. It uses an inkjet-printing technique to fuse together sand to produce sand cores and molds for metal castings. Later in the year, ProMetal (Irwin, PA) installed its first RTS-300 machine in Europe.

RSP Tooling LLC (Solon, OH) was also formed. RSP stands for Rapid Solidification Process, a steel spray process developed at the Idaho National Engineering and Environmental Laboratory (INEEL). In January 2002, RSP Tooling announced that it had reached an agreement to obtain an exclusive license for the RSP technology. An alpha test machine was completed in February 2002. Ohio-based Belcan is a partner and investor.

In early 2002, Stratasys introduced its Dimension product at a price of $29,900. The Dimension machine deposits ABS plastic, and is based on the former Prodigy product. The same year, Concept Laser GmbH began to sell its M3 Linear machine and EnvisionTEC GmbH (Ferndale, MI) began to sell its Perfactory and Bioplotter machines. The Bioplotter produces scaffold structures from various biochemical materials for tissue engineering.

Wuhan Binhu Mechanical & Electrical Co., Ltd. of China began to sell lamination, laser sintering, stereolithography and plastic extrusion (similar to FDM) systems in 2002. The same year, Solidscape introduced its T66 product, a lower-priced version of its drop-on-demand inkjet-based machine. Phenix Systems of France sold its first Phenix 900 system, which uses solid phase sintering to produce ceramic and metal parts.

After more than two years of offering services only, POM began to sell its direct metal deposition machine in 2002. It uses a CO2 laser, a 3-axis, overhead gantry CNC-motion system, and metal powders to repair tooling and aid in the production of tooling components. Meanwhile, Schroff Development stopped selling its inexpensive paper lamination machines.

Menix, Co., Ltd. of Korea sold its first VLM300 variable lamination machines in 2002. The system uses a 4-axis, hot-wire cutter to slice through high-density polystyrene sheets at an angle to minimize stair stepping and is priced at about $18,000.

Many exciting developments emerged during the industry’s first 15 years. Part two of this series will appear in the May/June issue. TCT

Tim Gornet is the manager of Rapid Prototyping Center Operations at the University of Louisville (Louisville, KY). For more information, visit http://louisville.edu/speed/rpc.