Additive manufacturing, or 3D printing, has been a popular method of creating prototypes since the 1980s and is quickly becoming the fastest, most affordable way to create custom consumer goods, as well. But how does this trendy technology work?


There are several different methods of 3D printing, but the most widely used is a process known as Fused Deposition Modeling (FDM). FDM printers use a thermoplastic filament, which is heated to its melting point and then extruded, layer by layer, to create a three dimensional object.

The technology behind FDM was invented in the 1980s by Scott Crump, co-founder and chairman of Stratasys Ltd., a leading manufacturer of 3D printers. Other 3D printing organizations have since adopted similar technologies under different names. The Brooklyn-based company MakerBot (now owned by Stratasys), was founded on a nearly identical technology known as Fused Filament Fabrication (FFF).

How FDM Works

3D printers that run on FDM Technology build parts layer-by-layer from the bottom up by heating and extruding thermoplastic filament. The process is simple:


Pre-processing: Build-preparation software slices and positions a 3D CAD file and calculates a path to extrude thermoplastic and any necessary support material.

Production: The 3D printer heats the thermoplastic to a semi-liquid state and deposits it in ultra-fine beads along the extrusion path. Where support or buffering is needed, the 3D printer deposits a removable material that acts as scaffolding.

Post-processing: The user breaks away support material away or dissolves it in detergent and water, and the part is ready to use.

What gets made

FDM is popular with companies in a variety of industries, from automotive (BMW, Hyundai, Lamborghini) to consumer goods manufacturing (Black and Decker, Dial, Nestle). These companies use FDM throughout their product development, prototyping and manufacturing processes.

The most common printing material for FDM is acrylonitrile butadiene styrene (ABS), a common thermoplastic that's used to make many consumer products, from LEGO bricks to whitewater canoes. Along with ABS, some FDM machines also print in other thermoplastics, like polycarbonate (PC) or polyetherimide (PEI). Support materials are usually water-soluble wax or brittle thermoplastics, like polyphenylsulfone (PPSF).

Thermoplastics can endure heat, chemicals and mechanical stress, which makes them an ideal material for printing prototypes that must withstand testing. And because FDM can print highly detailed objects, it's also commonly used by engineers that need to test parts for fit and form.

FDM is also used to produce end-use parts — particularly small, detailed parts and specialized manufacturing tools. Some thermoplastics can even be used in food and drug packaging, making FDM a popular 3D printing method within the medical industry.

Professional FDM printers typically cost between $10,000 and $300,000, which makes them one of the cheapest options for businesses investing in a complete 3D printing system.

Companies using FDM

While Stratasys is responsible for inventing FDM, it's not the only company profiting from this technology. Over the past two decades, FDM has become the most widely used 3D printing method in the world.

Many companies that manufacture FDM printers also offer a range of 3D printing services to clients, including external 3D modeling and printing.

FDM at home

Some FDM printers — like 3D System's Cube, MakerBot's Replicator and Stratasys' Mojo — are designed for use by hobbyists, inventors, do-it-yourselfers and small business owners. They're small, efficient and user-friendly.

But having one of these 3D printers in your home doesn't come cheap. The Cube is among the most affordable desktop FDM printers on the market at $1,299. MakerBot's machines are even more expensive, ranging in price from $2,549 to $3,299. And Stratasys' Mojo costs just under $10,000.

However, this popular technology is becoming less expensive as 3D printing startups, like the California-based Pirate3D, seek to bring 3D technology into the homes of average consumers. Pirate3D's Buccaneer, which is due out in December 2013 sells for just $347.

3D enthusiasts that don't wish to purchase a desktop FDM printer can build their own. There are many sites selling kits and parts for the "replicating rapid-prototyper" or RepRap, an open-source 3D printer design project founded at the University of Bath in the U.K. This FDM printer is continually being improved, but the ultimate goal of the project is to create a 3D printer that can print new copies of itself.

FDM Benefits

The technology is clean, simple-to-use and office-friendly

Supported production-grade thermoplastics are mechanically and environmentally stable

Complex geometries and cavities that would otherwise be problematic become practical with FDM technology

FDM Thermoplastics

FDM Technology uses the same tried and tested thermoplastics found in traditional manufacturing processes. For applications that demand tight tolerances, toughness and environmental stability – or specialized properties like electrostatic dissipation, translucence, biocompatibility, VO flammability or FST ratings – there’s an FDM thermoplastic that can deliver.