What material should you choose for 3D printing?

The properties of 3D prints are determined not only by the specific technology which it is using, but also consumables, on which both the mechanical properties of the element and a number of additional parameters depend. So how do you choose the most appropriate material for 3D printing?

Below is a summary of the most popular 3D printing materials used in basic 3D printing technologies together with the most appropriate applications for them.

FDM / FFF technology

The technology of 3D printing from materials in the form of a wire is distinguished by a large availability of various consumables. Which material will be used in the 3D printing process largely defines the properties of the finished element. The most popular materials for 3D printing in FDM / FFF technology include:

ABS – material for 3D printing, which has enjoyed unflagging popularity for years, due to its durability, which goes hand in hand with a relatively low price. The material is used in industrial applications – it is used, among others for the production of all kinds of housings, buttons, handles and others.

ABS should be chosen when:

• we need elements with high mechanical and temperature strength,
• we create models equipped with moving parts,
• we create models for further processing (e.g. grinding or drilling), without the risk of breakage,
• we 3D print utility models,
• we have a 3D printer with a built-in working chamber that is able to provide a constant 3D printing temperature,
• UV resistance of 3D prints is not a priority.

PLA – environmentally friendly thermoplastic material, for the production of which is used corn starch or sugar cane. Eagerly used for 3D printing due to trouble-free operation – it is easy to use and cheap, and material shrinkage is small, so the material does not require a heated table.

PLA should be selected when:

• we start working with a 3D printer and look for user-friendly material,
• we print 3D details for demonstration and educational purposes (e.g. demonstration models),
• we are looking for 3D printing material for prototypes or mockups,
• we make elements that require minimal processing and post-processing due to the fragility of the material,
• the resistance of the manufactured element to high temperatures UV radiation of 3D prints is not a priority.

ASA – is a material adapted to exposure to changing environmental conditions. Elements made of ASA plastic can be used, for example, in the automotive, energy and gas industries, agriculture or transport. They can also spatially print parts of external electrical boxes, gardening equipment and car side mirror housings.

ASA should be selected when:

• we need a 3D print with increased resistance to changing weather conditions,
• an important feature of the 3D printed element is to be thermal resistance,
• we are looking for material with ABS properties, but the priority is the possibility of exposure to UV radiation, without fear of loss of color or damage to the 3D model,
• we need 3D printing material for prototypes, functional production tools and everyday objects.

PET-G combines the most desirable features of ABS and PLA. First of all, thanks to the very good layer adhesion it is more durable, and the finished prints are quite flexible. In addition, it has a low shrinkage during 3D printing, which makes working with the material relatively easy.

PET-G should be selected when:

• the finished element is to be characterized by high chemical resistance and inertness to ultraviolet radiation and moisture,
• 3D prints are to have good strength properties – PET-G is impact resistant,
• we are looking for a translucent material with a characteristic “glass” finish,
• we are looking for a material that can be sterilized.

PA6 / Nylon is suitable for creating highly loaded structural elements such as tools, hinges, clamps, gears, functional prototypes and moving parts. It is a material from the class of engineering materials, and the operation process is more difficult than in the case of the materials described earlier. Nylon readily absorbs moisture from the air, so it’s best to store it in a waterproof bag with a moisture absorber.

Nylon should be selected when:

• the mechanical properties of the 3D printed element are important, e.g. enduring mechanical loads or resistance to abrasion,
  the material requires relative flexibility and resistance to high temperatures – the operating temperature range of nylon is 250-270°C,
• we have a 3D printer with a built-in working chamber that is able to provide a constant 3D printing temperature,
• the element must have a good surface finish.

Antibacterial materials are a group of materials with antibacterial and antiviral properties that have proven to be particularly useful during the COVID-19 pandemic period. Their special properties can be successfully used for 3D printing of replacement personal protective equipment.

Antibacterial materials should be selected when:

• we print 3D elements for which the shortest survival time of pathogens is a priority,
• we are looking for 3D printing material for replacement personal protective equipment,
• 3D printed elements will be used in everyday life, e.g. handrail covers and door handles.

SLA / DLP / UV LCD Technology

When choosing between materials for 3D printing from resins, it is worth paying attention not only to the properties of the materials, but also to the fact that the resin is compatible with your device. Currently, there are several technologies for hardening resins – e.g. using a laser, LCD screen or projector, and the materials differ from each other e.g. Among the available resins, basic types are distinguished:

Classic resins, i.e. the basic family of resins, suitable for 3D printing of models and prototypes, allowing for high-quality production of elements rich in details. Available in several colors, also in a translucent version, they allow for one-color 3D printing.

Classic resins should be selected when:

• we print 3D demonstration elements or conceptual models,
• we are looking for relatively cheap materials that will facilitate the creation of a new product, allowing, among others to present the next stages of product development in the form of prototypes,
• we want the best quality of 3D printing and presentation of precise details of the element,
• we print spatially transparent show models or prototypes.

Engineering resins are materials in which special emphasis is placed on the strength of elements and their mechanical properties (e.g. resistance to impacts or elevated temperatures). Functional prototypes and parts suitable for use can be successfully made of resin, since these materials are usually thoroughly tested for their technical parameters. In addition, these materials may have elastic properties.

Engineering resins should be selected when:

• we are looking for a material that will achieve 3D printing with the properties of the element, produced by classic methods,
• we create functional prototypes or parts for final applications,
• priority is 3D printing of elements with increased mechanical and thermal resistance,
• we need material with confirmed and tested technical parameters.

MJF / SLS technology

Polyamide 12 (PA12), or Nylon 12 is the most popular material used in powder 3D printing technologies (SLS and MJF). What characterizes PA12 is that:

• the material allows elements with good mechanical properties to be made,
• it is characterized by increased chemical resistance,
  ready prints have a matte, rough surface.

However, such systems are dedicated to mass production. The specificity of the technological process makes the technology profitable primarily for production series or large objects with complex geometry – small elements are more worth printing 3D using other additive techniques.