Processes - Additive Manufacturing
Laminated Object Manufacturing (LOM)
The first commercial Laminated Object Manufacturing (LOM) system was shipped in 1991. LOM was developed by Helisys of Torrance, CA. The main components of the system are a feed mechanism that advances a sheet over a build platform, a heated roller to apply pressure to bond the sheet to the layer below, and a laser to cut the outline of the part in each sheet layer. Parts are produced by stacking, bonding, and cutting layers of adhesive-coated sheet material on top of the previous one. A laser cuts the outline of the part into each layer. After each cut is completed, the platform lowers by a depth equal to the sheet thickness (typically 0.002-0.020 in), and another sheet is advanced on top of the previously deposited layers.
The platform then rises slightly and the heated roller applies pressure to bond the new layer. The laser cuts the outline and the process is repeated until the part is completed. After a layer is cut, the extra material remains in place to support the part during build.
Advantages
Large Build Volume Capability
LOM systems can produce very large parts without the size constraints typical of other additive manufacturing processes. The sheet-based approach allows for the creation of substantial components limited mainly by the sheet material dimensions and system capacity.
Material Efficiency
The process uses readily available sheet materials such as paper, plastic, or metal foils, which are typically less expensive than specialized powders or resins used in other additive manufacturing technologies.
Natural Support Structure
Excess material from each layer naturally provides support for overhanging features, eliminating the need for additional support structures during the build process.
Disadvantages
Limited Material Options
LOM is restricted to sheet-based materials and cannot process the wide range of materials available to other additive manufacturing technologies, limiting application possibilities.
Extensive Post-Processing
Parts require significant post-processing to remove excess support material, which can be time-consuming and labor-intensive, especially for complex internal geometries.
Limited Geometric Complexity
The layer-by-layer cutting approach limits the creation of complex internal features and curved surfaces, making it less suitable for intricate designs requiring fine details.
Capabilities
Disclaimer: All process specifications reflect the approximate range of a process's capabilities and should be viewed only as a guide. Actual capabilities are dependent upon the manufacturer, equipment, material, and part requirements.