3D print materials 3D Systems VisiJet Armor M2G visualized by 3D printed quadcopter frames.

Guide to the most common 3D print materials

The number of 3D print materials has grown extensively the past decade. There is now a multitude of various industrial-grade materials to choose from. Several of these are developed for additive manufacturing, but also for prototyping and testing. Here are the most popular 3D print materials explained for you.

PLA mostly used for 3D printed prototypes

PLA, short for Polylactic Acid, is a staple in the 3D print materials world and one of the most widely used materials. The material is derived from corn and sugarcane and is thus biodegradable.

PLA as a 3D printing material is usually filament based, meaning it is like a thread rolled on a spool. These spools are used in extrusion-based 3D printers, such as the Markforged Mark Two.

PLA is an excellent choice for a first material when you start using 3D printing. It is also suitable for quick iterations in product design, as it is inexpensive and easy to print with. The material can also be printed at low temperature.

Polypropylene – good for 3D printed lightweight parts

Polypropylene, or PP in short, is a semi-rigid and lightweight material. The material is tough and has a good fatigue resistance making it ideal for low strength applications like living hinges, straps, leashes, etc. A few manufacturers have even created polypropylene blends that have improved toughness making it suitable for practical use. PP is also one of the most widely used injection molded materials in the world.

In 3D printing, Polypropylene is commonly used in applications that require excellent chemical resistance combined with great flexibility and impact resistance. Amongst commercial plastics, PP has a very low density, allowing for the production of lightweight parts. Automotive, consumer goods, industrial and medical are key sectors that heavily use PP already.

One of several 3D printer solutions that can print with PP is the HP MJF 5200.

Polyamide one of the most popular 3D print materials

Polyamide is one of the most popular 3D print materials and has several benefits. The price level is reasonable and it can be used for interlinking and interlocking parts. Parts printed in polyamide can be finished in various ways, such as dying and vaporfusing.

In 3D printing, polyamide is often used as PA11 or PA12. PA11 produces strong flexible parts with excellent surface finish and detail. It is tensile, durable, high impact resistant and has high elongation at break. These properties make PA11 an excellent choice for snap fit plastic parts and those that require a high degree of flex such as prostheses,orthotic insoles, sports goods,  living hinges, and more.

PA 12 is one of the most common plastics used in industrial 3D printing because of it’s balance of excellent material properties, fine detail and low cost. This versatile plastic is flexible, has high impact resistance, is UV and water resistant, and is certified biocompatible. These qualities make it ideal for a wide range of uses in various industries including automotive, healthcare, consumer goods, and aerospace. This material is ideal for rapid prototyping and low-to-mid-range manufacturing.

PLM Group has one 3D printer solution that can print with polyamide, and that is the HP MJF 5200.

3D print material TPU demonstrated by hand twisting a flexible 3d printed part printed with the material Smooth TPU 95 from Markforged.

TPU enables flexible 3D printed parts

Thermoplastic Polyurethane, TPU, is a flexible, abrasion resistant thermoplastic. It is used in a variety of manufacturing processes for both consumer and industrial use. In certain mixes it can become very soft, but TPU material offers many benefits and features. 3D printed parts with TPU are durable and have the ability to withstand ambient temperatures of up to 80 degrees Celsius.

The material can withstand impacts and is resistant to many chemicals. Its versatile and used in many different industries. There are different versions of TPU material but in the main it can be classed as two types. The first one is Polyether Polyurethane, and the second Polyester Polyurethane. With both having different characteristics that can be suited to a specific need.

In PLM Group´s 3D printer portfolio, there are two 3D printer brands that can print with TPU. Firstly, the Markforged FDM 3D printers Mark Two, Onyx Pro and the Industrial series. Secondly, you can also print with TPU in the HP MJF 5200.

ULTEM – 3D print material for high temp industrial parts

ULTEM, or Polyetherimide (PEI), is a high-performance polymer that is amorphous. It offers superb thermal properties, a high-level of dimensional stability, extreme flame retardancy and excellent resistance to a lot of chemicals.

The material is popular in the aerospace industry, the automotive and medical industry. It is used in these industries because of its ability to handle demanding applications in a way that other thermoplastics can’t handle. For instance, for superior products where applications require a certain level of mechanical performance and flame retardancy.

ULTEM can be used in the 3D printer Markforged FX20.

Composite 3D print materials add mechanical properties

Composite materials are made up of more than one material. Often a plastic material is combined to give new properties. This can be strength, fatigue or surface finish. From an engineering perspective, composites usually contains reinforcing fibers. Carbon fiber, fiberglass, and Kevlar are three of the most common fiber materials used for composites. They are almost never used by themselves, but woven into sheets, wrapped into rods, or formed into custom molded shapes with the help of a matrix material to harden the fibers into an optimized shape. When many fibers are bound together to create larger parts, forces can distribute and disperse loads along the lengths of all of the fibers.

Carbon fiber has one of the highest strength-to-weight ratios. This makes it very valuable for creating lightweight, strong parts. The fibers are made up of carbon atoms. The crystal structure of the atoms is aligned into strands, making the strands incredibly strong in tension. Traditionally, thermoset resins are used as the bonding agent to set these fibers into a designated shape, cured around a matrix material like foam. In the context of 3D printing, the fiber can take two different forms:

Chopped fibers are short-length fibers chopped into segments less than a millimeter in length. These are mixed into traditional thermoplastics to form what is called a filled plastic. These can be printed with an FDM printing process.

Continuous fibers require a slightly different 3D printing method, in which continuous fiber strands are coated in a curing agent and laid down into a thermoplastic matrix extruded via a secondary print nozzle. This process is called Continuous Fiber Fabrication (CFF).

PLM Group currently has four 3D printer models that print with composites; Markforged Onyx Pro, Markforged Mark Two, Markforged Industrial series, and the Markforged FX20.

Manifold 3D printed in 3D Systems Tough Clear transparent 3D print material.

Resins used in DLP and SLA 3D printing

3D printing resins are liquid photopolymers, primarily used with technologies such as Stereolithography (SLA) and Digital Light Processing, DLP. Photopolymers are light-sensitive resins that change their physical or chemical properties when exposed to a light source, like UV.

Photopolymers are thermosets. This means that once the material is cured by a UV light, it cannot be remelted or reheated. Here at PLM Group, the Figure 4 3D printer platform from 3D Systems uses resins.
 
Resins are capable of creating objects with a higher resolution and smoother surface finish than many other 3D print technologies. With a range of colours and properties available, 3D printed resins are perfectly suitable for a range of applications, including visual and functional prototypes, end-use parts, medical devices and casting patterns for jewellery.

Below is a list of the most common resin types.

Standard

Standard resins provide highly accurate features and a smooth surface finish. Mainly used for prototyping.

Rigid

Rigid resin is a long-lasting material that is highly resistant to deformation over time. It is great for printing thin walls and features. It offers high stiffness and a high quality surface finish. It is often used for jigs and fixtures, prototyping and elecetrical casings.

Durable/Tough

Durable or tough resins simulate the properties of ABS and PP thermoplastics, allowing for greater strength, toughness and durability than standard resins. ABS-like and PP-like resins are suitable for functional prototypes, consumer products and generally low-friction and low-wear mechanical parts.

Transparent

Transparent resins deliver long-term stability and a versatile combination of mechanical properties for functional prototyping or end-use parts. It offers high light transmission that can be made fully transparent with post-processing. 

3D printing clear components is a cost-effective manufacturing process for product development. You can get visibility into the workings of complex assemblies, observe gas or fluid flows and reduce product design cycles.

The 3D printer 3D Systems Figure 4 can 3D print with the transparent material Tough Clear.

Flexible

Flexible resins can 3D print flexible parts with a rubber-like feel. Rubber-like resin can be compressed and bent, making it a good choice for squeezable models, wearables prototyping, grips and handles.

High temp

This type of resin gives high heat resistance and stiffness. Due to its thermal properties, high-temperature resins can be used to create tooling for short-run injection moulding and thermoforming, as well as various jigs and fixtures.

Castable

Castable resin is a cost-effective choice for the production of detailed patterns for investment or jewellery casting. During the investment casting process, a ceramic mould is made around a wax pattern. When the mould has solidified, molten metal is poured in to the mould. This creates the final metal part, while the wax is burned away.