3D printing technologies old and new

High profile companies such as Hewlett Packard are among those investing in building the systems that will enable 3D print to grow. Here are some of the systems currently available. 

REAL 3D printing - Carbon3D – “Up to 100 times faster” 

Inspired by the Terminator 2 sequence in which Arnold Schwarzenegger’s character takes the form of a robot, ceo Joseph DeSimone said at an MIT presentation on Carbon3D’s innovation: “Why can’t a 3D printer operate in this fashion where you have an object arise out of a puddle in essentially real time, with essentially no waste and made a great object.

Carbon3D’s system harnesses light and oxygen to grow a part continuously, according to DeSimone. It “controls the spatial light and oxygen” around the part being created.

“We see this as owning the intersection between hardware, software and molecular science.”

Joseph De Simone, Carbon3D's ceo

“The opportunity of making a part in real time that has the properties to be a [usable] part opens up the possibility of 3D manufacturing.

“We see this as owning the intersection between hardware, software and molecular science,” added DeSimone.

“We’re thrilled. The parts we’ve tested are strong in all directions, just like injection moulded parts. That’s the target we’ve been chasing after for decades.”

Ellen Lee, Ford 

Ford was the first OEM to work with Carbon3D. Ford has worked with 3D print for quarter of a century – from early concept prototypes to runnable and testable prototypes and limited production tooling.

Ellen Lee, team leader, additive manufacturing research at Ford, said: “What we are looking for in additive manufacturing is to be able to produce directly functional parts to use in our vehicles.

"What we are doing with Carbon3D is looking at the materials and helping to create the materials that would have these properties.

When you look at a typical SLA process it is a layer method where a layer of resin is put down one layer at a time. After the cure the next layer is put down.

In the Carbon3D process we are able to cure the layer while maintaining a continuous liquid interface so instead of having that stepwise layer by layer process we are able to do it more continuously. It can be done faster and the properties of the part are not impaired. They are stronger in both the printed direction and the other direction.

Ford used Carbon3D’s continuous liquid interface Production (CLIP) device to create an elastomer grommet to protect inner door wiring within its Focus Electric. CLIP technology allowed for a two third drop in production time, according to Carbon3D.

Similarly, after placing a V8 engine into a new vehicle body design, Ford required an oil connector. It designed an oil fill tube made with from both rigid and elastomeric PU materials to enable access, avoiding major redesigns to several components of the vehicle.

Lee said: “We’re thrilled. The parts we’ve tested are strong in all directions, just like injection moulded parts. That’s the target we’ve been chasing after for decades.”

Fused Deposition Modelling

Fused Deposition Modelling (FDM) uses thermoplastics deposited in layers to create a 3D printed object. During printing, the plastic filament is fed through a hot extruder nozzle. The plastic is softened to enable precise placement of the material with the print head.

The melted filament is then deposited layer by layer in the print area to build the item.

FDM was developed by Scott Crump in the late 1980s and commercialised by Stratasys in 1990.

StereoLithoGraphy

StereoLithoGraphy (SLA), like FDM is an additive method. Models are built layer by layer. SLA, however, uses a curable photopolymer – typically a liquid resin – that is hardened by applying focused light or UV light to cure.

SLA printers usually build the models from top to bottom and the build platform lifts the model upwards out of the resin bath.

The light source is either a laser or a digital projector (the technology is called DLP – Digital Light Processing). Lasers draw the layers; in DLP, an entire slice (a two-dimensional layer) of the model is projected at once into the resin bath.

Selective Laser Sintering

Selective Laser Sintering (SLS) is a technique that uses a laser as the power source. The laser sinters powdered material. Aiming the laser automatically at points in space defined by a 3D model binds the material together to create a solid structure.

It is similar to direct metal laser sintering but differs in technical details. Selective laser melting (SLM) uses a comparable concept, but in SLM the material is fully melted rather than sintered.

SLS is a relatively new technology that so far has mainly been used for rapid prototyping and for low-volume production of component parts.

Rapid jet fusion method

It involves using inkjet printing technology to apply a heat-absorbent ink onto a powder bed, which is then cured using an infrared lamp.

California, USA-headquartered Hewlett Packard unveiled its long-awaited Multi Jet Fusion 3D printer range in May 2016. BMW has begun a process of integrating HP’s new technology into its manufacturing methods for parts production, according to a July 2016 press release.

Covestro has a range of PUs that it said are “ideal for the rapid multi-jet fusion method”.