Which is the most optimal 3D printing filament for architects?

3D printing filaments for architecture models

Choosing the right type of printing material is becoming an increasingly difficult task because the 3D printing market is witnessing the continual emergence of new and innovative materials. There are numerous factors influencing this kind of decision-making, such as strength, accuracy, and eco-friendliness. Polylactic Acid and Acrylonitrile Butadiene Styrene, commonly called in their short forms as PLA and ABS, respectively, are the two main filaments used in Fused Deposition Modelling (or FDM, for short); these two materials account for 75% of the current 3D printing market. However, choosing between these two materials is a dilemma because their differences are not outwardly clear. This raises a question: Which one is best suited for your architectural applications?

In order to answer the question, we reached out to three architects — Jarno Vesa, Henrik Bejmar, and Sofie Magne. Jarno is a 3D printing expert at JKMM, one of Finland’s most successful architectural offices, with 86 prizes in design competitions. Henrik is an experienced architect who has worked with 3D printing in some of his projects. Henrik is currently working for Wingårdhs, whose Kajen 4 building was awarded “Building of the Year in Stockholm” in 2015. Having tried 3D printing for a few months, Sofie, from SWECO Architects, also shared her opinions about 3D printing material.

The blog sums up the key differences between ABS and PLA, in terms of visual quality, durability, smell, temperature resistance, and storage, thereby helping you to choose the most optimal filament for your designs.

Visual Quality

PLA is able to deliver smoother print details than ABS: PLA-printed models come out with sharper and more precise features, corners and surfaces. Sofie emphasizes that architects do not print any usable models but only scale models of a high visual quality. In addition, Jarno reveals that the ABS printed parts are “too shiny”. He asserts that architects prefer printing matte white materials because traditional architectural models are matte white.

PLA delivers smooth print details with sharp and precise features. Source: 3D Printing RVA

PLA delivers smooth print details with sharp and precise features. Source: 3D Printing RVA

 
PLA and ABS printed parts. Source: SmartLego Flickr

PLA and ABS printed parts. Source: SmartLego Flickr

Durability

ABS is widely used for constructing durable parts such as the ever-popular Lego blocks. JKMM uses ABS as it is the only material option for their printer (the Mojo). To Jarno, the material is durable, and easy to sand and finish.

Natural PLA vs Natural ABS. Source: Printcountry.com

Natural PLA vs Natural ABS. Source: Printcountry.com

Traditional PLA is weaker and more brittle than ABS. However, with technological advancements in polymers, many reinforced blends of PLA are now tougher than ABS. Furthermore, Jarno points out that the sturdiness (or durability) of a material is not important for architectural purposes, which lead to our conclusion that ABS is not an optimal choice for you as an architect, though its durability property would be better preferred for mechanical (or kinetic) prototypes and designs instead.

Regular PLA and new reinforced PLA. Source: Octave 3D

Regular PLA and new reinforced PLA. Source: Octave 3D

Smell

As an oil-based plastic, heated ABS generates a hot plastic smell. Printing ABS requires well-equipped ventilation during printing, otherwise, the fume emission can be unpleasant (and potentially a health hazard) for users and the people working in the same place. On the other hand, PLA is made from plant-based materials, specifically corn-starch and sugarcane. For this reason, the material is more eco-friendly than other plastic materials, which Jarno and Sofie affirm is always an advantage for a filament. What makes PLA more pleasant to use than ABS is the slight sweet smell give off when this sugar-based material is heated, while the fume emitted from PLA is considered an improvement over the hot plastic fume associated with ABS.

Temperature Resistance

ABS has a high temperature resistance. The temperature range used for printing with ABS filaments is between 210°C and 250°C. On the other hand, PLA has a far lower melting point than ABS; the melting temperature is within the 180–220°C range.

When printing with ABS filament, the printing surface needs to be smooth, flat and clean. ABS plastic shrinks significantly after cooling down. In other words, the finished parts tend to warp and fall apart from the base. Hence, the printing bed also has to be heated to an ideal temperature in a closed environment. If not heated up properly, ABS will have difficulty in sticking to the build plate and can start to warp. So, it takes a considerable amount of time to learn and perform this heating-up process, which means less time spent on design work.

Bed adhesion issues. Source: 3D Hub

Bed adhesion issues. Source: 3D Hub

Compared to ABS, it is easier to obtain successful prints with PLA, which stick to the bed and do not warp. Imagine when you as an architect have time constraints of making a scale model: how would you feel if you noticed that your print was warped halfway through the print, and then you would have to restart the process? When printing with PLA, the bed does not need to be heated nor be in a closed environment. Thus, a heated bed is never a concern for an architect who prints and showcases with PLA.

When printing with PLA, the bed does not need to be heated nor in a closed environment. Source: Brendan Hesse

When printing with PLA, the bed does not need to be heated nor in a closed environment. Source: Brendan Hesse

Storage

In the long term, exposure to a humid environment affects the printing process, as well as the quality of the printed parts. ABS kept in a moist environment will spurt from the tip of the nozzle when printing and increase the risk of clogging up the nozzle. PLA kept in a moist environment may result in discoloration and reduction in printed part properties. In addition, storing PLA at high temperature (160–350ºC) can result in the part warping or melting.

Which 3DP filament is suited for the architect?

Jarno, Henrik and Sofie grade 3D printing materials along three main criteria: visual quality, ease of printing, and mechanical performance. In terms of visual quality, Jarno mentions the ease of sanding the finished model. Henrik, on the other hand, refers to visual quality in terms of how well the adhesion is between the layers of material. The ease of printing involves the required preparation time, frequency of failed prints, and fume emissions. Sofie emphasizes the importance of eco-friendliness in choosing 3D printing materials. Mechanical performance refers to the heat resistance and the maximum pressure that the finished object can undergo. It is not as important for the architects as visual quality and the ease of printing.

All things considered, ABS and PLA hold several similarities: prices are more or less identical; when heating these thermoplastics, both give off fumes, with ABS having a hot plastic smell, while PLA has a slightly sweet smell; and lastly, the two filaments are required to be stored in dry and cool locations as both are prone to melting and warping.

There are also several key differences between the two materials. PLA helps you print your scale models with higher visual quality [over ABS], whereas ABS printed parts can withstand a much more rigorous wear and tear than PLA. This better durability and higher temperature resistance make ABS a preferred choice for engineers and those requiring mechanical uses. In addition, one of ABS’ requirements is a heated print-bed while PLA’s printing bed doesn’t need to be heated. This makes PLA easier to use. With companies becoming more eco-conscious, finding ways to reduce their carbon footprint, the plant-based PLA supports this effort, unlike the oil-based ABS. When you combine these advantages, PLA becomes an optimal choice for prototyping and perfecting the aesthetics of your designs.

Scale model of proposed construction project on campus printed by PLA. Source: Citrix Flickr

Scale model of proposed construction project on campus printed by PLA. Source: Citrix Flickr

The development of new printing materials in the 3D printing industry is associated with PLA’s advancements. Manufacturers have continuously improved the formulations of traditional PLA and come up with advanced PLA blends, while different colours of PLA can be mixed to create new colours and gradients. PLA can also be mixed with wood, brick, bronze, brass, or stainless steel, resulting in low warping and better printing performance. Henrik is excited to experiment with new 3D printing materials that helps him get a tangible feeling of his scale models. In a nutshell, PLA is believed to be an optimal choice if you are eager to experiment with new and innovative applications.

PLA with Wood. Source: MakerGear Forum

PLA with Wood. Source: MakerGear Forum

What did you find interesting about this blog? What are you experiences with PLA or ABS? What are your requirements for choosing 3D printing materials? What type of 3D printing materials are you using? And which types of materials would you like to experiment with? Share with us in the Comment section below.

Julio Tiusanen