Intro to Additive Manufacturing:
Materials & Performance

Materials are the lifeblood of additive manufacturing. Oftentimes referred to as consumables, the advancements in 3D printing materials have been extraordinary with no signs of slowing down. Material developments are driven by the demand for stronger and specific solutions that lead to new applications. Chemical resistant thermoplastics used for the oil & gas industry, high performance nylons used as a substitute for short-run production, and impossible to produce metal printed parts that are complex and perfect for end-use assemblies in aerospace​. As mentioned in previous chapters, the book of additive manufacturing continues to evolve and every technology, process and material is becoming a viable solution somewhere, for someone. Forbes published a recent survey​ conducted with 1,300 respondents across North America and Europe that demonstrates significant increases from 2015-2019 for additive applications​—​specifically production, spare parts and R&D.

The Complexity of Consumables

The beauty of 3D printing is also the beast that plagues many design and production engineers. The world of additive materials is vast; however, it’s important to remember that a singular technology or process will ​not​ be compatible with every material available. For example, one artist wishes to use watercolors and requires a round brush and a specific canvas. The other desires to paint a variety of surfaces​—​justifying a more versatile material, such as acrylic. It becomes quite challenging to understand the complexity of the consumable market in additive manufacturing and the compatibility with different technologies. The ​Pyramid of Performance was created by our staff of subject matter experts to showcase the realm of possibilities 3D printing offers. In addition, all of these materials are available at ​Forecast3D​.

AM Materials Foundation

Beginning with the basic foundation of the most widely used and adopted thermoplastics, we start to understand how and why these materials are used for functional prototypes and design validation practices. Within this particular segment of the pyramid we identify the materials in two different categories, (1) ABS plastics and (2) simulation rigid materials. Depending on your application and strength requirements, these materials are often used to replicate the real product. However, for those who wish to evaluate their designs, check form, fit and function, or who see this as an opportunity to share highly aesthetic parts for feedback sessions with colleagues or clients​—​these are cost effective and ideal materials.

ABS Plastics

ABS Plastic​ is the most widely used material in additive and traditional manufacturing. Commonly used as an injected molded material for countless industries, it’s no surprise that this material has become ideal for product designers and prototype developers. There are several variations of ABS plastic offered at GKN Additive (Forecast 3D) that vary in structural properties and aesthetics. For example, ​ABS - M30​ offers increased strength capabilities equipping engineers with a low-cost solution ideal for concept modeling and manufacturing tools. Finally, ​ASA​ is an advanced version of ABS plastic that boasts exceptional UV resistance characteristics, making it an ideal material for outdoor products and applications.

Simulation Rigid Materials

Why simulate rigid materials when you can simply print ABS plastic instead? ABS printed plastic is predominantly available on FDM and FFF printers which, due to their printing process, may not have the required aesthetics your team requires for product validation, feedback or focus group sessions. Therefore, SLA and PolyJet technology offers an array of materials that are not as structurally sound as ABS plastic, but do provide exceptional finish quality that are ideal for visual applications. In our experience, it’s the perfect material option for client feedback sessions and upper management discussions, and is an exceptional resource for marketing to build their promotional campaigns with early product images or physical demonstrations at trade events.

So what works for your application, SLA or PolyJet? Both are thermoset polymers that offer high resolution parts with smooth, injection mold-like finishes. Here is a quick breakdown:

• SLA 11122 XC Watershed is a water-resistant material that mimics ABS plastic quality and is one of the clearest materials available on the market. Ideal for medical and consumer product applications.
• SLA NeXt offers a new generation of material that facilitates the production of tough, complex parts with improved moisture resistance and improved thermal properties.
• PolyJet Vero prints in 16 micron details and is available in several different color palettes. This technology is ideal for the fabrication of complex assemblies.
• PolyJet Rigur is an improved photopolymer that simulates polypropylene and is ideal for flexible closures or living hinges.

Specialty Materials & Flexibles

Moving up the pyramid or materials indicates an increase in strength or capability. This particular segment identifies two distinct categories of additive materials, (1) specialty materials, and (2) flexibles. While the additive manufacturing market has exploded with different versions of plastics and simulation materials, so has the demand for materials that solve niche applications. This section is dedicated to understanding how, and why, these materials are being used in the marketplace today.

Specialty Materials

There are several materials within this segment that have been implemented across various industries to solve unique problems. Most notably, materials developed for medical and industrial tooling applications have expanded within the past decade. It’s important to remember that each material presented belongs to a specific technology, and it is rare that a facility will have access to this wide array of capabilities.

The first medical material, ​ABS - M30i​ is biocompatible (ISO 10993 USP Class VI) and typically used within the medical, pharmaceutical, and food packaging industries. The second biocompatible material available is ​Med610​, operational under the PolyJet umbrella, which is approved for cytotoxicity, genotoxicity, delayed type hypersensitivity, irritation and USP plastic class VI. Skin contact is approved for up to 30 days, making it ideal for hearing aids, prosthetics and orthotic applications.

When it comes to tooling for manufacturing applications, there are two materials available that make a world of difference as it relates to time and money for engineers. First, ​ST-130​ belongs to the FDM family and is used primarily to build sacrificial tools enabling the production of hollow composite parts. This material can withstand the heat and pressure of autoclave curing and has become quite the resource for engineers designing highly complex parts. Second, ​PerForm​ is a ceramic-based SLA material that has the lowest viscosity of any stereolithography material with excellent detail resolution, outstanding stiffness, and superior high heat tolerance. Ideal for tooling, wind tunnel testing and high temperature testing.

Flexibles

The ability to 3D print soft-touch parts is a distinct advantage for consumer product, automotive, and medical device designers. ​Thermoplastic polyurethane (TPU)​ is a class of polyurethane plastics with many properties, including estaticity and transparency, and is resistant to oil, grease and abrasion. There are different versions of TPU offered within the additive market, and it’s valuable to understand which materials belong to their respective technology.

• MJF ​Estane 3D TPU​ is a flexible material produced through a joint collaboration between HP and one of the most well-known chemical companies on the planet, ​Lubrizol​. Known for developing industrial grade materials, Lubrizol stands behind the versatility of this material. It’s often used for end-use parts that require high tear strength and rubber-like flexibility.
• MJF ​TPU 88A BASF Ultrasin​t is another material born from the collaboration with major industry leaders. This time, BASF offers a high wear/abrasion resistant material that is an excellent choice for shock absorption applications. Lauded as a material that provides high accuracy, detail and smooth surface finishes.
• PolyJet ​Agilus30​ is a Shore A value thermoset material that is traditionally used to build durable, tear-resistant prototypes that can withstand repeated flexing and bending. It’s the only flexible material on the market capable of achieving a clear and transparent finish.

Advanced Thermoplastics For Production

The current demand for materials that solve production, spare part, and R&D applications have grown year-over-year for the past five years with no signs of slowing down. ​Airbus implemented additive manufacturing​ to produce non-load bearing, cabin interior components that have enabled the company to significantly cut down on weight, reducing gasoline expenditures. In 2018, ​American automotive manufacturer, Ford, opened a 135,000 square foot Advanced Manufacturing Center in Michigan​ to be the go-to facility for all things 3D printing. Even the injection molding industry has been impacted with the ability to ​3D print cost effective injection mold tools​ for short run production applications. It’s become quite obvious that 3D printing has become a viable solution for manufacturers due to the advancements in the following materials.