Manufacturing mechanically and thermally resilient components with industrial 3D printing

Choosing the right 3D printing material is also particularly important in additive manufacturing! Which technical properties are particularly important for my application? What do the terms bending strain and bending stress as well as tensile strength mean? How important are chemical, mechanical, thermal or electrical properties of the material?

What actually characterizes a functional part?

By definition, the term “functional” refers to the ability of a part to meet its design intent. Each of the requirements listed below is a general functional requirement for a 3D printed part. We have defined each requirement, listed how both short-fiber-filled polymers and CFR meet the requirement, and highlighted which technology has a greater impact. Markforged parts incorporate both technologies, using a short carbon fiber-filled polymer reinforced with continuous fibers.

Important mechanical and thermal properties of 3D printing materials

Function requirement Descritption Short fiber filled polymer Continuous fiber reinforcement
Stiffness The extent to which a material deforms under load Short fibers increase stiffness by 1.5 to 3 times compared to conventional polymers. Continuous fibers increase stiffness by 20 times compared to conventional polymers.
Strength Maximum load the material can withstand before it gives way The addition of short fibers slightly improves the tensile and flexural strength of the materials. In addition, continuous fibers increase strength by up to ten times.
Durability, shock resistance The ability of a material not to break under impact loads and to absorb energy Nylon is known for its durability and resistance to breaking under impact. The addition of short fibers further improves wear resistance. Continuous fibers increase the resistance of parts so that they do not deform until much later.
Durability, wear The ability of a material to resist the gradual removal or deformation of surface material by friction. Short fibers increase the abrasion resistance of the polymers so that they last longer in abrasive environments. The fiber is not exposed until the outside of a part is worn through – in extreme cases, it can even provide abrasion resistance when exposed.
Accuracy How close a part is to the toleranced dimensions – both immediately after printing and after some time in use Short fibers improve the volume drag coefficient of materials, which improves printing accuracy and reduces printing errors. CFR has no effect on initial part accuracy, but prevents dimensional creep over time, which is common with plastics.
Heat resistance The reaction of a material to elevated temperatures in the application Short fibers help stabilize the material at elevated temperatures, reducing warpage. High-strength, high-temperature (HSHT) fibers and other long fibers withstand heat much better than matrix polymers, allowing HDT to rise up to 145 °C.
Resistance to chemicals How a material reacts when it is exposed to aggressive chemicalsv chemicals that are present in the manufacturing environment are present Fiber-filled polymers based on nylon-based polymers are resistant most of the solvents and solvents and lubricants used in lubricants used in manufacturing. CFR has only a limited effect, since the fibers generally not exposed to chemicals are exposed.

Thermoplastic for demanding technical purposes

The Markforged base material Onyx 

Onyx can be used to produce bend-resistant, strong and accurate parts. Onyx is already 1.4 times stronger and stiffer than ABS and can be reinforced with continuous fibers of any type. Onyx sets new standards for surface finish, chemical resistance and heat resistance.

Flexural strength 71 MPa
Flexural modulus 3.0 GPa

The Markforged Continuous Fiber Materials. 

Before we dive into applications, let’s briefly define CFR. CFR is a process that allows 3D printers to reinforce Fused Filament Fabrication(FFF) parts with continuous filaments. A CFR-enabled machine uses two extrusion systems: one for conventional FFF filament and a second for continuous filaments with long strands. Continuous fibers are laid out layer by layer and replace the FFF infill. The resulting parts are significantly stronger (up to ten times stronger than any FFF material) and can replace aluminum parts in the application

Low hurdle for functional parts

Many 3D printing technologies offer customizability and low cost complexity – the big difference of CFR is that this is also possible for functional parts. Compared to parts 3D printed in the FFF process, parts produced in CFR have special advantages and properties, such as:

  • Stronger parts – CFR allows you to dynamically change the strength of parts: from the strength of plastic to that of aluminum. This allows users to design and additively manufacture parts as strong as they need.

  • Durability – CFR parts last longer than any other FFF 3D printed parts due to the strength, stiffness and durability of the continuous filaments in the application. In addition, filled plastics are very wear resistant and tough.

By producing functional parts, CFR 3D printers are narrowing the gap between engineers and the core of production in some important ways:

  • No more waiting for quotes or depending on in-house processes – manufacturers don’t have to send out a drawing for a part and then wait for a quote or the availability of an in-house machinist.

  • Automated manufacturing process – No labor is required to produce the parts, as 3D printers are fully automated.

  • Parts at the point of need – 3D printers are flexible to use and relatively affordable for most businesses. Conventional manufacturing typically requires the purchase of expensive machinery, outsourcing of parts, and can require a significant amount of space for deployment.

  • Heat and Chemical Resistance – CFR parts can withstand ambient heat in most manufacturing environments, and the short, fiber-filled filaments that reinforce them are extremely chemical resistant.

How are functional requirements mapped to applications?

“Functional” is not a singular term in manufacturing – different applications have different functional requirements. Below, we map the functional requirements that 3D printing fulfills to common applications. We have divided the requirements into critical and recommended, where critical means a requirement that is met by almost all parts in that application, and recommended means a less important or universal requirement. It is important to note that there is diversity even within specific applications.

Learn more about 3D printing continuous fibres!

Which continuous fibre is suitable for which applications? How do I design correctly for filament 3D printing? What do users say and where can I find more information? – This is the right place for you! We listed some information leading you directly to the matching answers.

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