Welcome to another Creatz3D Fun Fact Series!
We have always been told that the patented heated chamber in Stratasys FDM machines is integral in ensuring 3D print success, especially when working with engineering-grade thermoplastics. But why is it so?
To start off, we have to once again begin with the FDM and FFF debate. Both technologies work similarly by extruding heated filament but their results differ drastically because of the overall machine build.
So for over 2 decades, Stratasys held 3 exclusive patents to use its heated chamber design in their FDM 3D printers. The exclusivity meant that competing manufacturers found it difficult for them to break into the industrial FDM market. This is because engineering-grade materials typically require high temperatures to work properly.
When the FDM patent expired in 2009 after 20 years when it was filed by Stratasys founder, Scott Crump, it led to the birth of mainstream consumer 3D printing led by the RepRap Project. Consumer 3D printers attempted to circumvent the patented heat chamber via heated build plates. While the build plate is able to try and regulate the environment to prevent warping and improve adhesion to the build plate for the first layer… that’s about it.
The Cost of “Good Enough”
To put things into perspective such as when we 3D print with ABS, it requires supplemental heating to reduce part warpage. Consumer FFF printers is able to keep the part’s bottom layers hot and prevent the part from detaching from the build surface, but it can only effectively do it at lower temperatures which means heat from the build plate cannot reach the printing layer. The result – warpage, delamination, cracking, and part distortion.
Some manufacturers also attempt to get around this by altering the material formulations with impact modifiers. While this may result in a material that’s less prone to warping, it come at the expense of other thermal and mechanical properties and will differ significantly performance-wise from final injection-molded parts.
This is unlike industrial-grade FDM 3D printers that employ a fully enclosed heated chamber to rapidly warm the entire build chamber at high temperatures for optimal print conditions from the first layer to the last.
The Heated Chamber USP
While integral to day-to-day 3D printing, the heated build plate is quite simply not enough on its own when it comes to engineering filaments. There are multiple design features found in the patented heated chamber that ensures that you never lose control of your part’s quality, accuracy, and consistency.
1) A highly specialized electronic control algorithm maintains an accurate temperature across the chamber. That means no dead zones and complete use of the build volume, a feature not reflected in most desktop printers.
The patented airflow design of the heated chamber provides precise temperature control right where the material is extruded. This is really important for avoiding curled parts. It also lets you print solid parts with engineering materials that require higher temperatures for successful results.
Cross-flow oven design for even heat distribution.
Large heaters enable faster heating
and higher temperatures.
2) Consistent temperature at each build layer maintains layer-to-layer strength from top to bottom. Printers with only a heated bed lose temperature control as the built-up layers get further from the bed, resulting in cracking between layers.
Cross-chamber ventilation maintains consistent temperatures across the build platform, resulting in better Z-layer strength. Most other desktop systems that use a heated build chamber only use single-side blowers.
3) Dual-wall construction and a double-wall door keeps the heat where it needs to be — inside the build chamber.
Large heaters bring the build chamber up to operating temperature quickly, accelerating the overall build cycle. They’re also capable of maintaining the elevated temperatures that are needed to print certain thermoplastics which other desktop printers just can’t reliably print.
Double-wall oven and door retains heat.
With the patent expiration, the high-temperature industrial FDM market with PEEK, PEKK, and ULTEM material capabilities is expected to become much more competitive. But the expertise of Stratasys in this area over the decades plus continuous R&D means that they have a good headstart over everyone else seeking a share of the market.