Date Visited: 25 October 1995
JTEC/WTEC Attendees: C. Atwood (report author), R. Aubin, P. Fussell
Also in attendance for 30 minutes was a representative from Schneider Prototyping GmbH, a service bureau located in the same industrial facility as Cubital:
Dr. Henri-Jacques Topf
A brief summary of the JTEC/WTEC team's visit with Dr. Topf follows the Cubital report.
The Cubital site in Bad Kreuznach is dedicated to marketing, sales, and service to all of Europe. Cubital is a spin-off company from Scitex Corporation and began operation in 1987. Commercial sales began in the fourth quarter of 1991. It currently has facilities in Raanana, Israel (company headquarters and R&D activities), in Germany, and in the United States. In addition, it has representatives and agents in East Asia. Cubital has 38 employees worldwide. To date, Cubital has sold a total of 26 machines. Its customers are from automotive, aerospace, consumer products, and medical industries, as well as engineering firms, academic institutions, and other research institutions. Seventy percent of users of the solid ground curing (SGC) machines are rapid prototyping service bureaus. Cubital's goal is to establish a leading position as a production machine developer within the rapid prototyping (RP) industry.
Cubital's SGC system is an additive process that uses ultraviolet (UV) light to selectively cure thin layers of liquid monomer. The SGC machine is considered a production process by its manufacturer and by RP users because it has the processing capacity for high throughput. This is accomplished by nesting many parts throughout the entire build envelope and hardening the entire layer in one go, using a photomasking technique. The SGC process consists of the five sequential steps listed below:
After using Cubital's Data Front End (DFE) software to preprocess and slice the 3D CAD model into individual layers, an image of each layer is produced on an electrostatically charged erasable glass plate using Cubital's proprietary ionographic printing techniques. The image, serving as a photo-mask, is positioned over a thin layer (typically 0.004-0.008 in. thick) of liquid photopolymer (resin). The resin is then selectively solidified by a powerful UV light through the mask, creating that layer of the model.
After the layer is cured, all unsolidified resin is collected for recycling, leaving the hardened areas intact. The cured layer is passed beneath a strong linear UV lamp to cure the layer to final strength.
Melted wax is then spread into the newly created cavities. The wax is cooled and hardened to provide continuous, solid support for the model as it is fabricated.
The layer is then milled to a smooth, accurate, even surface.
A new layer of photopolymer is spread on the milled surface, a new mask is generated on the cleaned glass plate, and the process is repeated until the build is complete. After the build is finished, the wax is removed, and the parts are ready for use or additional post- processing, if necessary.
Cubital manufactures and sells two solid ground curing machines. The Solider 4600 is an entry level machine; two have been sold. The capacity of the 4600 machine is 35 cm x 35 cm x 35 cm (14 in. x 14 in. x 14 in.). It can build parts at a rate of 550 cm3/hr at 120 sec/layer regardless of part geometry or number of parts being built. The Solider 5600 has a larger build volume of 50 cm x 35 cm x 50 cm (20 in. x 14 in. x 20 in.) and builds parts twice as fast as the 4600.
Cubital has achieved its objective of building a machine that is fully automated and reliable. The Solider machines are considered to be technologically mature and Cubital is now concentrating on marketing the existing platforms. The company's strategy is to market the devices for use as production machines. In addition, Cubital is looking for new and unique applications for its processes and is seeking teaming relationships with chemical and resin companies to develop new materials. Cubital received initial funding support for R&D activities from the Chief Scientist's Office of the Israeli government. Cubital has filed between 20 and 30 patents, some of which are being evaluated for other applications.
Cubital currently offers two types of materials for use in its Solider machines. The primary material is photopolymer resin, and the secondary material is wax. The photopolymer materials are G5601 and XA7501. These are conventional materials used to make plastic models. Research efforts are focused on developing an epoxy resin to compete with 3D Systems' epoxy resin and on developing a new methodology for making wax patterns for investment casting. This includes developing a new wax material that is suitable for use in the lost wax process of investment casting. This wax is different from the wax that is used as a support material in the SGC process.
The Cubital SGC process fabricates complex plastic models used for design validation and as functional models. New applications are in various stages of development.
Cubital is currently working to develop a method for fabricating wax patterns for investment casting. This includes capturing the wax pattern in a thin polymer coating, then removing the polymer coating from around the wax pattern. This process is in the early stages of development. Small, simple patterns were shown to the team.
Tooling was mentioned as a focus of R&D at Cubital. Development of epoxy resin is evidence of this effort.
There were no examples of medical applications cited, although the systems can read and build parts from data received from various CT and MRI equipment.
Cubital has developed a proprietary software package called the Solider Data Front End (DFE). This software has editing and file manipulation capabilities that prepare adequate STL files for processing on any RP system. Features include cutting, patching, facet trimming, scaling, and file preview.
Included in the site visit with Cubital was a 30-minute visit with Dr. Henri-Jacques Topf, Managing Director of Schneider Prototyping.
Schneider is the largest rapid prototyping service bureau in Germany. It began operation in 1992 and has experienced rapid growth, consistent with the growth that leading U.S. service bureaus have experienced in the past few years. Schneider has 30 employees representing a diversity of skills. The market it serves is limited to Europe and Israel. Schneider is located in the same industrial complex as Cubital and operates a Cubital Solider 5600 machine. In an effort to meet customer needs, Schneider has added a variety of other manufacturing processes to its facility. In addition to the Solider 5600, it offers CNC machining, vacuum molding, silicon molds, and other processes. Near-term plans are to add capabilities for fabricating tooling for injection molds, spray metal tooling, and cast tooling. The goal is to produce 100-500 production quality parts with a 3- to 4-week turnaround time. Schneider managers are currently investigating the possibility of adding another RP process to its capabilities. Dr. Topf stated that reducing the cost of materials would help Schneider's competitiveness.
Approximately 60% of the company's customers are from the automotive industry, 25% are from consumer products industries, and the rest are from electronics and other industries. Metal parts produced from investment casting RP patterns account for 15-20% of the work of Schneider Prototyping. A request by the JTEC/WTEC panel to tour Schneider's work facility was denied.