A momentous day for the 3D printing industry was 3 January 2014, when the stocks of two of its leading companies, 3D Systems and Stratasys, peaked after nearly 30 years in business, and hopes were high for the technology.
Many observers thought 3D printing would allow consumers to produce customizable goods directly from their homes. The price of goods would be slashed, international trade deficits reversed, ethically suspect supply chains rendered unnecessary. It was to be the next industrial revolution.
But this date was also the start of a precipitous two-year decline that saw 3D Systems’ shares lose more than 92% of their value and Stratasys’s fall by over 86%. Expectations plummeted as well; 3D printing turned from saviour to gimmick. Industry analysts and researchers now agree that the hype far outpaced the practical applications. Why?
3D printing: A history
In fact, additive manufacturing or rapid prototyping — the original less-sexy terms for 3D printing — has been around since the 1980s. Stereolithography, which uses ultraviolet lasers to solidify light-sensitive plastic resin built up in layers to produce three-dimensional objects, was patented in 1986 and led to the formation of 3D Systems.
Using a different technique – Fused Deposition Modelling (FDM) – Stratasys was founded in 1989; it uses heat to melt plastic filaments, that is then built up in layers. The majority of the early business enjoyed by both was with industrial clients who needed rapid prototyping and could afford printers that cost at least five figures.
Then, the price of 3-D printers began to fall in 2005. Hundreds of developers built upon recently expired patents and kept their new designs freely available, making progress swift and inexpensive. As a result, the cost of 3D printers dropped by a factor of about 100.
Three early pioneers banded together in 2009 to form MakerBot. In June 2013, Stratasys acquired the company in a stock deal worth $403 million. Unfortunately the enthusiasm was ill-founded and there roved to be a gulf between expectations and reality.
Despite these issues, analysts remain optimistic. In 2013, Wohlers Associates, a consulting firm that specializes in 3D printing, predicted that the sector would grow to $10.8 billion by 2021. But while the firm is now sceptical about low-end, consumer-oriented printers, they predict that more and more industrial clients will be buying and implementing those high-end, expensive 3D printers.
Pushing the barriers of FDM
Traditionally, the Stratasys FDM process uses a 3-axis deposition head to melt spool-fed tubes of thermoplastic material and extrude the molten plastics in thin layers on a heated build-plate. While simple and stable enough to build impressive objects and tools, this has always presented a few fundamental limitations:
- Most professional-grade FDM machines deposit materials in a closed, heated oven to help each layer properly melt and adhere. This presents an obvious limitation to the size of objects that can be printed.
- The quality of the parts have been limited to the capabilities of the deposition heads. Even under extremely controlled conditions, it is difficult to maintain a temperature and deposition rate consistent enough to meet some production standards in highly-regulated industries like aerospace.
- Speed – the process builds parts from scratch slowly upwards, layer by careful layer
- The functionality of FDM parts is limited by the single-material nature of FDM – whereas other 3D printing systems have made a lot of progress in the multi-material, multi-colour capabilities, FDM has remained single material, single colour.
- These limitations have always limited FDM to creating innovative new jigs, fixtures and moulds and robust prototypes, but final part production has always been just out of reach.
Now, the company’s Infinite-Build 3D Demonstrator can print objects with an unlimited z-axis in multiple materials consistently and accurately, faster than ever before. Turning the geometry on its head, the Z axis of the part slides horizontally out the back door as far as it needs to go.
A new approach to material deposition replaces the heated tube liquefiers with a screw-type extruder that feeds flakes of thermoplastic materials to the head in a controlled, repeatable, and traceable process that is designed to guarantee consistency and accuracy throughout the build.
PTFE now 3D-printable
The limited range of available materials is another hurdle obstructing the wider adoption of 3D printing. Many of the most commonly used industrial plastics still aren’t widely available for 3D printers. Together with its subsidiary Dyneon, industrial polymer giant 3M, one of the world’s leading manufacturers of polytetrafluoroethylene (PTFE) and other fluoropolymers, is announcing at the global plastics and rubber trade show K 2016 (Düsseldorf 19-26 October) a patent-pending technology that enables fully-fluorinated PTFE polymers to be 3D printed.
PTFE is an extremely useful material, used in many everyday products. It is corrosion resistant (inert), very hydrophobic, and also has one of the lowest friction coefficients of any solid – this makes it perfect for non-stick coatings for bakeware. It is also a very good option for various hospital applications, such as catheters.
Traditionally, parts made from PTFE and other fluoropolymers are manufactured using expensive techniques such as sintering, which typically create a lot of waste. It is also difficult to create very complex structures. 3D printing has the potential to offer more sustainable manufacturing and a wider variety of designs.
3M plans to offer a print-on-demand service for spare and custom parts. This “service bureau” business model is becoming increasingly common as the technologies to print the materials become more complicated and the materials become more difficult to handle.
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