Laminated Object Manufacturing, commonly known as LOM, is an innovative rapid prototyping technology that constructs three-dimensional objects by bonding and precisely cutting sheets of material under computer control. This process involves layering sheets of material—such as paper, plastic, or metal—that are adhered together and then shaped through cutting with a blade or laser. The core concept of LOM is to build objects by stacking and shaping these sheets, enabling rapid and cost-effective prototyping. Initially developed and commercialized by the California-based company Helisys in 1991, LOM quickly gained recognition as a viable manufacturing method alongside other emerging 3D printing technologies like Fused Deposition Modeling (FDM) introduced by Stratasys in the same year.
Over the years, various companies have advanced LOM technology. Helisys rebranded as Cubic Technologies in 2000 but eventually ceased operations. In recent times, Irish firm CleanGreen3D, which acquired assets from Mcor Technologies in 2019, continues to develop and enhance LOM systems, particularly emphasizing full-color capabilities. The essence of LOM is to utilize adhesive-coated sheets—primarily paper, but also plastics and metals—glued together layer by layer. These layers are shaped using either a blade or laser to form the desired 3D structure. Once assembled, the object can be further refined through machining or drilling, making LOM a versatile process for various prototyping needs.
While paper remains the most common material due to its ease of use and low cost, plastic and metallic sheets are also employed, albeit with increased complexity in cutting and handling. As an additive manufacturing approach, LOM is valued for its rapid turnaround times and affordability, particularly suited for creating prototypes rather than mass production. The accuracy of the final product is influenced by the thickness of each material layer, typically rendering it less precise compared to other methods like stereolithography or selective laser sintering. Nonetheless, LOM’s benefits include inexpensive feedstock, the potential for full-color printing, and the ability to operate within standard office environments, making it an attractive choice for many design and engineering applications.
The Operational Mechanics of Laminated Object Manufacturing
LOM operates through a systematic layering process, beginning with a sturdy build platform onto which sheets of material are sequentially fed. These sheets are typically coated with an adhesive layer, which is activated and melted using a heated roller as the sheet advances into position. This adhesive ensures each new layer bonds securely to the previous one, gradually building the 3D object from the bottom up.
Once a sheet is in place, a precision cutting tool—either a mechanical blade or a laser—is employed to trace the object’s cross-sectional geometry as dictated by the CAD model. Excess material is then removed via cross-hatching or trimming, facilitating the easy removal of waste and ensuring accurate shaping. This process repeats: each new sheet is fed, adhered, cut, and bonded, layer by layer, until the entire structure is complete.
During construction, the build platform gradually descends, making room for subsequent sheets. This layered approach allows for the creation of complex geometries, including hollow sections and internal features, although internal undercuts can pose challenges. When paper-based materials are used, the resulting models can resemble wood in appearance and texture, often requiring sanding or sealing with paint or lacquer to improve durability and moisture resistance. The ability to produce multi-material or multi-color layers enhances the versatility of LOM, especially for prototypes requiring visual realism or color differentiation.
Advantages of Laminated Object Manufacturing
LOM presents numerous advantages that make it a popular choice in rapid prototyping and certain manufacturing contexts. Its primary strength lies in the use of inexpensive and readily available feedstock materials, such as paper, which significantly reduces costs compared to traditional 3D printing materials. This affordability allows for quick iteration cycles and makes LOM accessible even to small businesses or educational institutions.
Another notable benefit is the capability to produce large components with substantial build volumes, as the process does not rely on complex support structures like some other additive manufacturing techniques. Since the layers are laminated and self-supporting during build, complex overhangs and open structures can be fabricated without additional supports. Additionally, the process can incorporate color into the layers, enabling the creation of visually appealing, full-color prototypes, marketing models, or artistic pieces.
LOM systems are also adaptable to standard office environments, as they do not require industrial-grade conditions, making in-house prototyping feasible. The method’s speed allows for rapid iteration, and the produced models exhibit properties similar to wood, enabling easy post-processing such as sanding, drilling, or painting. These qualities collectively make LOM a flexible and cost-effective choice for visualization, presentation, and functional mock-ups.
Limitations and Challenges of Laminated Object Manufacturing
Despite its numerous benefits, LOM is not without limitations. Its primarily subtractive nature means that creating highly complex geometries with internal channels or intricate undercuts can be difficult, as internal access for support removal or post-processing is limited. Internal voids or complex internal features often require manual intervention or alternative manufacturing methods.
In terms of dimensional accuracy, LOM generally falls short when compared to technologies like stereolithography (SLA) or selective laser sintering (SLS). The layer thickness and cutting precision influence the final detail, often resulting in less smooth surface finishes. Furthermore, paper-based models are susceptible to moisture absorption unless properly sealed, which can compromise structural integrity or appearance over time.
Another challenge is the limited availability of hardware and ongoing development in the market. As few companies focus exclusively on LOM, the technology risks obsolescence, and finding expertise or support can be difficult. The mechanical parts of the system, such as blades or laser modules, can also wear out and require maintenance, adding to operational costs. Overall, while LOM excels in speed and cost-efficiency for certain applications, its limitations should be carefully considered when selecting the appropriate manufacturing process for complex or high-precision projects.
Pros and Cons of Laminated Object Manufacturing
- Pros:
- Affordable feedstock materials, especially paper, reducing overall costs
- Operational in non-industrial, standard office environments
- Potential for vibrant, full-color models
- Suitable for creating large and expansive structures
- Supports overhangs without additional supports due to layered self-supporting nature
- Allows fabrication of composite laminates through material layering
- Cons:
- Lower dimensional accuracy compared to SLA, SLS, or DLP methods
- Internal geometries and undercuts are difficult to achieve and remove
- Surface finish may be rough or uneven, especially with paper-based models
- Paper parts are prone to moisture absorption unless sealed properly
- Limited hardware manufacturers, leading to potential obsolescence
- Mechanical wear and maintenance of cutting mechanisms
Applications and Use Cases of Laminated Object Manufacturing
While LOM may not serve as a direct replacement for all other 3D printing techniques, it is highly valued in specific applications where its unique features are advantageous. Its affordability and ability to produce sizable, detailed prototypes make it particularly suitable for rapid prototyping in various industries. For example, companies can utilize LOM to quickly generate visual models for client presentations, design validation, or concept demonstrations, especially when color is an essential factor.
Furthermore, LOM’s compatibility with office environments allows teams to perform in-house prototyping without investing in expensive industrial machinery. The full-color capability makes it ideal for creating marketing materials, promotional items, or artistic displays like 3D printed selfies, toys, or customized props.
In architectural modeling, laminated paper offers a material akin to wood, but with the benefit of digital speed and precision. Architects and designers can produce detailed, large-scale models rapidly, replacing traditional manual methods like balsa wood crafting. In manufacturing, LOM is also used to create sacrificial patterns for sand or investment casting. A CAD-designed object can be printed in paper, then encased in a mold. After burning out the paper, the mold is ready for casting, streamlining the pattern-making process.