Many organizations are looking to additive manufacturing and 3D printing to revolutionize their manufacturing operations. These newer methods of manufacturing are taking over by providing organizations with a cost-effective way to create parts that have unique geometries and structures, have remarkable strength-to-weight ratios, and are completely custom.

3D printing has revolutionized the manufacturing industry.

In order to begin implementing an additive manufacturing process into an organization, you must select a 3D printer. With so many variations available on the market, it can be a daunting task to figure out which will provide the functionality you need while also providing efficient ROI.

How to Pick a 3D Printer: Understanding How Additive Manufacturing Methods and Materials Work Together

In order to successfully pick the right 3D printer for your organization, there are a lot of components to consider. The biggest and most obvious thing teams must think about is the types of parts they want to print, as well as how strong they want them to be. Organizations must also consider both the materials and methods they plan to use to find the right printer.

Organizations should think about all of the following:

  • What parts or products do you want to be able to print?
  • What are parts going to be used for? Final end-use parts? Just prototyping?
  • Do you want to use parts straight off the printer, or is it okay to do some additional post-processing?
  • What materials do you want to use?
  • Do you want strong parts? Do you want light parts? Both?
  • What types of things will your parts be exposed to?
  • What type of software will your printer need to be compatible with?
  • How quickly do prints need to be finished?
  • What kind of precision/resolution do you want your prints to have?
  • What things may you want to use this printer for in the future to ensure you are making the right investment?

By considering both present and future needs, your organization can better select a 3D printer that will provide the best ROI.

3D Printing Methods

The techniques used to print parts, along with the types of material used, will have a significant impact on how the part performs. By determining ahead of time what types of products you want to create (end-use parts, prototypes, etc.), you have a starting point for which 3D printing method you should use and, therefore, what printer will work best.

Fused Filament Fabrication (FFF)

Fused filament fabrication is by far the most commonly used 3D printing method. It uses thermoplastic or composite materials to create prototypes and models.

  • Thermoplastics: These plastics are heated so their melted form can be laid down layer by layer through the nozzle of the 3D printer. Depending on how the parts are designed, they can have low density or be completely hollow. With the right structures in place, and depending on the material, these parts can be strong even with low density.
  • Composite materials: These materials combine thermoplastics with secondary material fibers to create a stronger composite material. They are laid down using the same methods as thermoplastics, but given the microscopic overlapping structures of the composite fibers, the material is much stronger. In addition, this mixing of materials allows parts to have a smoother finish, increased stiffness, and improved dimensional stability. These elements together allow the parts to be used right off of the printer without any post-processing needed.

Selective Laser Sintering (SLS)

SLS also uses thermoplastic materials to create 3D prints. The main difference between FFF and SLS is that instead of melting down the materials and then laying them down one layer at a time, SLS melts only specific portions of the part into the desired shape.

This additive manufacturing technique lays thermoplastic powders down one layer at a time and then goes over the print with a laser to selectively melt and bind specific parts of the powder. By layering the materials in a crosshatch pattern and then using a laser to selectively bind materials, parts have increased strength and isotropic properties.

Continuous Filament Fabrication (CFF)

Previously, 3D printing metal parts was extremely expensive and time-consuming, although that has changed (see Atomic Diffusion Additive Manufacturing). CFF was designed to be a cost-effective and competitive option to 3D printing metal parts. It uses a continuous strand of filament (fiberglass, carbon fiber, etc.) surrounded in thermoplastic. Once the part has been printed, the entire thing is cured. The combination of continuous filaments and thermoplastic together provides incredible strength-to-weight ratios as well as durability that is comparable to metal parts.

Property Test Standard Carbon CFF Kevlar® CFF Fiberglass CFF HSHT Glass CFF
Tensile Strength (MPa) ASTM D3039 700 610 590 600
Tensile Modulus (Gpa) ASTM D3039 54 27 21 21
Tensile Strain at Break (%) ASTM D3039 1.5 2.7 3.8 3.9
Flexural Strength (MPa) ASTM D790* 470 190 210 420
Flexural Modulus (GPa) ASTM D790* 51 26 22 21
Flexural Strain at Break (%) ASTM D790* 1.2 2.1 1.1 2.2
Compressive Strength (MPa) ASTM D6641 320 97 140 192
Compressive Modulus (GPa) ASTM D6641 54 28 21 21
Compressive Strain at Break (%) ASTM D6641 0.7 1.5 n/a n/a
Heat Deflection Temperature (%) ASTM D648
Method B
105 105 105 150
*Measured by a method similar to ASTM D790
Source: https://nxrev.com/wp-content/uploads/2016/07/MF_Mark-Two-3D-Printer-DS-FNL-Web2.pdf

Stereolithography (SLA)

This 3D printing method is similar to selective laser sintering as they both use lasers as their primary curing component. SLA dispenses already liquefied photopolymers one layer at a time and then cures them with the laser. This technique creates extremely strong parts by taking advantage of the molecular composition of the material. The molecular composition, combined with the laser curing, creates parts that are fully dense, are isotropic, and can be extremely detailed.

Atomic Diffusion Additive Manufacturing (ADAM)

ADAM is a revolutionary method for 3D printing metal parts that was specifically designed for the Markforged Metal X printer. It combines techniques from metal injection molding and 3D printing to create metal parts faster than previous methods.

ADAM technology uses metal powder that is encased in thermoplastics and laid down layer by layer to create the initial part. Once the printing process is complete, the entire part is washed to remove the plastic binding. Next, the part is placed in an oven to allow the, now exposed, metal powders to fuse together. Unlike traditional 3D printing metal parts, in which metal powders must be handled in special chambers, ADAM is much faster, safer, and cost-effective.

Selective Laser Melting (SLM)

SLM is the more traditional metal 3D printing method that was used before the creation of ADAM techniques. It uses SLS methodology with metal materials. Using SLM, metal powders are laid down layer by layer within an inert gas chamber. When the print is complete, the part is selectively fused together using a powerful laser. Once the initial printing and sintering are complete, the part must then go through numerous post-processing steps (cleaning, removing supports, finishing, etc.) to be ready for use. Due to the high heat used, and part-warping possibilities, SLM has some geometric limitations that make it best used for small functional metal parts like implants.

3D Printing Materials

The strength, durability, and elasticity of parts are highly influenced by both the 3D printing methods and materials used. The flexibility of 3D printers allows many of them to work with numerous materials, making the possibilities endless for 3D printing materials.

Different types of materials have different chemical compositions, levels of elasticity, and durability. Understanding how you want your parts to function will make it easier for you to select the right material.

Here are some of the most common materials:

Thermoplastics

Thermoplastics are the most common material used in 3D printing. Their relatively low cost makes them the most ideal material for creating prototypes quickly and efficiently. Their composition allows them to squish instead of shatter under pressure, providing increased durability. However, they have a low melting point and low chemical abrasion resistance, making it impractical for end-use parts.

Composites

Composite materials combine two distinct material types to take advantage of the structural properties of both. Composite materials are mostly created to operate as filaments in most 3D printers. They have high strength-to-weight ratios and can be used in numerous engineering applications.

Photopolymers

Photopolymers start as liquids and then turn to solids when exposed to specific types of light sources. The main difference between thermoplastics and photopolymers is that the molecular properties of the material changes once it is exposed to light, so the parts cannot be melted once cured. However, because they cannot be melted they have low elasticity, causing them to be much more brittle than other 3D printing materials. In addition, continued light exposure can cause the part to break down.

Metal

Using metal has been possible in 3D printing for a while; however, previous methods used straight metal powders and required additional safety precautions for handling. Newer advancements in 3D printing metal have made the material much safer to handle. In particular, the metal used in the Markforged Metal X uses metal powders that are encased within thermoplastics. Both metal form materials use high heat to fuse powders together before post-processing.

How to Pick a 3D Printer: Find a Technology Partner

Once you have determined what types of parts you want to create and what methods and materials you want to use, it is time to select a printer. With so many models available on the market, it can be confusing to find the right one to suit your organization’s present and future needs. We recommend finding a technology partner, like NxRev, to help you throughout your research and purchasing process. Someone with additional expertise about the available solutions will be able to guide you to the right solution.

Want to learn more about 3D printing or our available 3D printers? Check out these other articles:

Or, if you’re ready to get started or are looking for more assistance, simply contact us.