3D printing technologies additively build 3D parts layer by layer. Despite being a relatively newer form of manufacturing, additive manufacturing has seen a lot of development in the past 20 years. This development has enabled us to be able to print parts in a variety of materials including UV curable resins, powders and thermoset filaments depending on the 3D print technology utilized.
All these new means of additive manufacturing, and material selections means that there is a much higher learning curve to ensure you have selected the right choice for your application.
In this post, I aim to help streamline your learning process by highlighting all the main 3D printing technologies; FDM, PolyJet, SAF, DLP, and SLA. I will also help you better understand the targeted applications for each technology and will discuss what makes each technology unique.
Fused Deposition Modeling (FDM)
Fused Deposition Modeling (FDM) is one of the most common Additive Manufacturing processes on the market.
This format of 3D printing technologies uses a print head to heat a filament thermoset to its molten state. The printer will move the printhead in a desired path to iteratively build a part layer by layer. One of the main advantages of FDM additive manufacturing is the ability to print parts with a variable infill density.
Depending on the application, engineers and designers may require different mass properties or different mechanical properties. FDM presents the ability to generate different infill geometries and densities which will ensure that parts will be strong enough for their applications and will also remain light.
Due to its rapid adoption, and its ability to print in high performance thermoset plastics, we see a very wide range of applications for FDM technology.
Tooling and Manufacturing Aids
One of the main applications for this technology is in the development of tooling and manufacturing aids. Some of the main tooling we see being made are parts for forming and molding sheet metal, work holding fixtures, CMM fixtures, go/no go gauges, drill jigs and fixtures and much more.
These fixturing and tooling components have proven to help streamline the manufacturing process while also reducing the tooling cost and tooling waste. We have experienced that manufacturing facilities that have adopted to using an FDM technology in their facility have noted a reduction in product rework and scrap and have also noted a decreased time to part and final assembly.
Prototyping is another strong area where FDM additive manufacturing excels. Companies have turned to FDM additive manufacturing because it has given them the ability to iterate much faster and much cheaper than they have been able to before. FDM has allowed the ability to produce a part, test its fit and function and then redesign it until a final solution has been met.
End Use Parts
Stratasys prides itself on being an industry leader who consistently is working to improve print speed, quality, repeatability, and material availability. These aspects have helped FDM be recognized as a manufacturing solution for end use parts as well. We see this in many industries but most notably in the aerospace industry. The Fortus F900 printer and Ultem 9085CG resin are being used to print flight ready parts straight off the printer.
PolyJet 3D Printing Technology
PolyJet 3D printing closely resembles the way your home office inkjet printer prints, the main difference of course is the PolyJet prints in 3D whereas inkjet printers only prints in 2D.
PolyJet printing uses highly precise piezo electric print heads to deposit the desired UV curable resin onto the build plate. The 18-micron layer of UV curable resin is then exposed to a UV light source which polymerizes the resin. Once that layer is complete the printer will deposit fresh resin onto the previous and will build the part layer by layer until it is complete.
Referring back to how this process is similar to your inkjet printer, you can think of it in a sense of your printer printing iterative cross sections of the three-dimensional model.
Since PolyJet takes advantage of pizio electiric head technology, it has the unique ability to blend and mix both color and materials to fit the needs of a wide range of application. The utilization of materials like Vero, Agilus30, and Elastico materials enables designers to print the full spectrum of CMYK and enables engineers to achieve specific part hardness, both rigid and rubberlike.
PolyJet printing is a very unique technology as it has the ability to blend and mix materials and colours to achieve very specific part colour and flexibility.
Since PolyJet printers have the capacity to print virtually any colour you can think of, it pairs very well with marketing models and product development models. We see many companies turning to this technology to print very realistic, highly detailed product models to help support focus groups and tradeshow marketing campaigns.
The medical field takes advantage of the ability to print in many different colours and print in different flexibilities. The Stratasys J850 Digital Anatomy printer, can run models derived from DICOM imaging data files. Those 3D printed models can be used to create educational anatomy models which will aid student learning by giving the students something physical that they can rotate and visualize, for an enhanced learning experience.
To take this point even further, doctors and surgeons are also printing patient specific medical models using materials, such as RadioMatrix, BoneMatrix, and TissueMatrix that mimic different biological properties of anatomical features. This gives them the ability to practice difficult surgeries before going into the operating room, ensuring they are fully prepared for any situation that may arise.
Dental is a newer niche application for 3D printing and additive manufacturing. Recently Stratasys has unveiled and added their new line of materials known as TrueDent to their dental materials line up. True Dent is a proprietary FDA (Class II) resin that is being used to create hyper realistic dentures, crowns and bridges that match the physical appearance of the original teeth.
Prototyping Mechanical Parts.
Although PolyJet has the ability to print parts in a wide range of colours (including clear) for visual aesthetics, it can achieve very fine features. So, we are seeing a rise in mechanical parts being printed as well. Polyjet systems can run materials like DraftGrey, a quicker and cheaper alternative to full color printing for engineers who want to prove out a concept quickly or in a flexible material for increased impact resistance for bumpers spacers, and fasteners.
Selective Absorption Fusion (SAF)
Selective Absorption Fusion (SAF) is a new, powder based additive technology developed by Stratasys to bring a production level additive manufacturing solution to market. What makes this technology very desirable for end users is the ability to print near isotropic parts with Nylons and Polypropylene.
This technology begins its process by dispensing a very even, thin layer of the powdered polymer (Nylon PA11, PA12 or Polypropylene). Once the layer is set, the printer will use its piezoelectric print heads to dispense a catalyst resin which will act as the cross-sectional layer of the part. The catalyst then gets exposed to a UV lamp and transfers the heat energy from the light to the powder which fuses the powder together.
From there the printer will iteratively build new layers on top of the previous ones until the build is complete. The layers get used together by the UV catalyst resin and this fusion results in parts with near isotropic mechanical properties.
End use Parts and manufacturing support
Since the H350 and the SAF technology has the ability to print parts in large volumes, we see a lot of end users turning to it for manufacturing support to alleviate supply chain issues and also use it as the main manufacturing method for end use parts.
To further this, we find automotive part manufacturers and medical device manufacturers to be very quick to adopt this as a manufacturing solution because their current parts are already being manufactured with nylon and polypropylene.
A recent example of this is in the orthotic manufacturing space. We were working with a company who was producing polypropylene foot orthotics for patients and wanted to utilize the H350 to help increase production speed and automate their manufacturing. We found this to be a perfect end use for this technology because it required less manual labour than their current CNC process, reduced scrap and manufacturing waste and was perfectly suited to print organic shapes regardless of the patient foot size.
Digital Light Projection (DLP)
Digital Light Projection (DLP) additive manufacturing technology utilizes a resin vat with a transparent bottom and a build plate that descends to the bottom of the resin vat. Below the vat is a UV light projector that selectively illuminates portions of the build plate. These portions act as the cross section of the part and cures those sections only.
Once that layer is complete the build plate will raise up and the light projector will cure the next layer. This process is repeated iteratively until the build is complete.
One of the main advantages to this form of additive manufacturing is it enables the user to achieve a very high level of throughput. Since the whole build plate cross section gets cured at the same time, it will be able to print ten parts in the same amount of time as it would one part, assuming all ten can fit on the build tray.
End use Part Manufacturing
We see the Origin One being applied for many end use part manufacturing applications. The ability to nest parts in a build allows itself to be a competing technology for part throughput. Many users seek out the Origin One because the parts it produces resemble the surface finish of an injection molded part at a fraction of the cost and time to develop the tooling and mold the part.
The Origin One paired with the Stratasys Open Material License enables users to print parts with various mechanical and physical properties. Depending on the application, we are able to print parts that are incredibly strong and tough or print more elastomer type materials.
Since users have the ability to print elastomers, we see many manufacturers opting to use the system to produce parts that compete with silicone and urethane cast parts. For example, we have seen users print fixturing components with elastomers which ensure that the A face of a painted part doesn’t get scratched, scuffed, or marred when working on it.
Stereolithography (SLA) additive manufacturing is like DLP printing in that it utilizes a vat of resin and a curing process to build the part. The main difference is SLA printing uses a laser to cure the parts as opposed to a light projector.
Although this means you aren’t able to cure the whole layer at once, you have the ability to print parts with a much smoother surface finish and with better accuracy.
The Stratasys Neo utilizes the SLA print technology to produce very precise prints that have exceptional surface finish and resemble injection molded parts. The very smooth surface finish, large print volume, quick print time and material availability makes the Neo a very attractive prototyping tool.
One example of a manufacturer using the Neo for prototyping parts is McLaren Racing. McLaren have partnered with Stratasys to use the Neo to print aerodynamic models in Somos PerFORM Reflect material of their Formula One race cars for wind tunnel testing. The Neo has allowed them to produce geometrically accurate models due to its incredible surface finish and has also given them the ability to iterate designs much faster than ever before.
The smooth external finish of SLA prints paired with low absorption resins allow users to create 3D printed molds for a variety of molding applications, such as sand casting, urethane casting, and metal casting. Somos WaterShed AF was specifically designed for the investment casting process, also known as lost wax casting. No antimony is used in the formula of WaterShed AF, so patterns created with this material leave lower ash residue after burnout. This results in less clean up and quicker turnaround times, saving metal casting foundries significant time and cost.
3D Printing Technologies Expert Guidance
As you can see, today the additive manufacturing industry covers a wide range of 3D printing technologies and applications. Each application can be paired with one or more types of 3D printing technology. I hope this post helps you navigate all the 3D printing technologies for your applications. If you have questions or like to know more, feel free to reach out to us. Our team of application engineers is ready to help you navigate your situation and help you integrate additive manufacturing into your current processes.