Currently, numerous organizations are researching and developing Layered Solid Manufacturing (LOM) equipment and technology. Leading companies and research institutions include Helisys from the United States, Kira and Sparx from Japan, Solidimension from Israel, Kinergy from Singapore, and prestigious domestic institutions like Huazhong University of Science and Technology and Tsinghua University.

Among these, Helisys has the largest market share internationally. The company’s technology has made significant advancements in the field of LOM. In 1984, Michael Feygin proposed the method of layered solid manufacturing, and in 1985, he established Helisys. In 1992, Helisys launched its first commercial machine, the LOM-1015 (with a table size of 380mm x 250mm x 350mm), followed by the LOM-2030 in 1996, which featured a larger table size of 815mm x 550mm x 508mm. This newer model was 30% faster than its predecessor. In addition to its original line of LPH, LPS, and LPF paper materials, Helisys has also developed plastic and composite material options. On the software side, Helisys has continually improved its LOMSlice software, with the latest version designed for Windows NT 4.0. New features include STL visualization, error correction, Boolean operations, and enhanced fault alarm systems.

Key Players in LOM Equipment Development

1. Helisys (USA) Helisys is a pioneer in LOM technology, producing some of the earliest commercial machines in the market. Their machines have advanced over time, with newer models offering faster prototyping speeds and larger production volumes. Their software and hardware developments have made them a leader in the field.
2. Kira Corporation (Japan) The PLT-A4 model from Kira uses ultra-hard cutting tools combined with selective bonding techniques. This approach allows for high-precision prototyping, especially for more intricate and detailed models.
3. Solidimension (Israel) Solidimension’s SD300 model is similar to a 3D printer and features a USB interface, making it suitable for desktop use. The SD300 uses engineering plastic films, producing transparent amber-colored models with a minimum wall thickness of 1.0mm. This device is compact and suitable for small-scale rapid prototyping applications.
4. Kinergy (Singapore) Kinergy’s equipment also focuses on improving the quality and precision of the LOM process, utilizing high-quality components and innovative design to produce reliable machines with minimal operational issues.

Domestic Research and Development: Huazhong University of Science and Technology and Tsinghua University

In China, significant advancements have been made in LOM equipment by institutions such as Huazhong University of Science and Technology and Tsinghua University.

1. Huazhong University of Science and Technology The HRP series of thin-layer LOM machines developed by Huazhong University stand out for their unique features in both hardware and software. The hardware is built using internationally recognized components to ensure high reliability and performance. Key features of these machines include:
   • X-Y Scanning Unit: The system employs AC servo drives and ball screw transmissions, ensuring high precision, speed, and smooth operation.
   • Material Feed System: A unique no-tension material feed mechanism ensures high-speed, reliable material feeding with minimal waste.
   • Exhaust and Ventilation System: The machine is equipped with a dynamic blower and powerful exhaust system, ensuring efficient smoke and dust removal during operation.
   • Laser System: The system uses high-quality CO2 lasers, which are stable, reliable, and capable of providing superior cutting quality with a long lifespan. The lasers can also switch gases for different materials and are equipped with a closed-loop water cooling system.
   Huazhong’s HRP2001 software provides a robust graphical user interface with an open modular structure. It supports STL file recognition, error correction, slicing technology, real-time dynamic simulation, and high-precision control of the cutting process. The system also includes unique technologies such as mesh subdivision and laser energy control, enhancing the overall quality and speed of the prototyping process.
2. Tsinghua University Tsinghua University has developed the SSM-500 and SSM-1600 LOM machines. The SSM-1600 is currently the largest rapid prototyping machine in the world, capable of handling parts with dimensions up to 1600mm x 800mm x 700mm. The machine is designed for large-scale rapid prototyping and is particularly suitable for manufacturing large molds. Its key technical features include:
   • Advanced Parallel Processing Technology: This unique technology, which has been patented in China, significantly improves processing efficiency.
   • Fast Plate-type Hot Pressing Device: Another patented technology that allows for rapid and high-quality bonding of layers.
   • Tension-Free Paper Feeding Technology: A patented feature that improves material utilization and reduces waste.
   • High-Precision Motion and Control Systems: These systems ensure that the SSM-1600 maintains high reliability and precision throughout its operation.
   • High-Performance Laser and Optical Systems: These systems provide excellent cutting quality and precision, making the SSM-1600 suitable for large-scale manufacturing applications.

Conclusion

The development of LOM equipment is progressing rapidly with contributions from leading companies and research institutions worldwide. In particular, Helisys, Kira, Solidimension, and Kinergy have made significant strides in refining the technology. In China, institutions like Huazhong University of Science and Technology and Tsinghua University have made noteworthy contributions, with their machines offering high precision and large-scale capabilities. As LOM technology continues to evolve, we can expect even more advanced equipment that can produce high-quality prototypes quickly and cost-effectively. The combination of superior hardware, innovative software, and cutting-edge laser technology will undoubtedly make LOM an even more powerful tool in the world of rapid prototyping.