PLA vs. ABS

The 3D expert focuses on ABS vs. PLA, new exciting exotic materials and other exciting innovative things!

The next wave of development within 3dprinting is not necessarily only about new printers and new technologies - no, we need to look a little closer at the filament, the consumable material that is extruded in a 3dprinter. We will take a closer look at the different filaments available and give some small tips and tricks that we have found useful over time in connection with 3dprinting.

We hope you will make use of our little guide and take the leap into other materials and find new and exciting materials for your next creative project.

We gradually see on a daily basis that new 3d printers are coming to the market and that the technology is becoming more complete and specialized as time goes by, which means that you now see that (FFF), also known as FDM printers, achieve completely new results - in terms of print quality and ease of use is concerned. In addition, we also see that the printers are becoming more precise and that the speeds are increasing - at the same time that items that are printed can be smaller and far more detailed than you have previously been able to achieve with a hobby/semi-professional 3d printer.

As it appears now, limitations within 3dprint are not in the development of new printers and their technology, but rather in the chemical limitation found in the 3dprinter material that has to go through the machines. The limitation is that the filament must be melted into a liquid material, extruded through a very precisely dosed nozzle and then cooled down again.

Most 3d printers today have a more or less advanced cooling system consisting of one or more small active fans that help the extruded material to cool down in the best possible way - there are, however, limits to how much you can blow on a subject before it will deform or "warp", which we will get into later.

So how do we move forward?

Once you have accepted that 3dprint is not a fast technology and that it all takes time, you can open your eyes to the possibilities in the many different filaments/materials available on the market. This area is where great development really takes place and where there is really an opportunity to work with one's creativity.

This writing will deal with 3dprint and the many materials that can be used within 3dprint. We will also explain a little about the technology - it can be useful knowledge for both new and experienced users of 3dprint - we hope you can use it =)

In order to print with "exotic" filament, there will often be special requirements for most machines you print on, the software used and not least the experience you have as a user - however, it is rare that you see that it is not possible to print with other materials than what is typically recommended - perhaps your own machine can even print with exotic material without you being aware of it?

The two celebrities

ABS

ABS is an abbreviation for Acrylonitrile Butadiene Styrene. If you are one of those who followed chemistry lessons at school, you will probably notice that the last two words sound very chemical. The last word sounds a lot like polystyrene , which is used in many forms of packaging - and most people have, as a child / young person, held a flame to some packaging and seen that it melts and has a very special bad smell. The molten part is what makes ABS a thermoplastic polymer that is usable in FFF 3dprint.

ABS has been used in industrial 3d printing for many years and has always been a very popular plastic in the development of filament for 3d printing: it melts reasonably consistently at around 230 degrees Celsius, which can easily be achieved with 3d printers in the hobby category. It is a relatively strong material, slightly flexible and has a relatively high melting temperature (glass transition) of around 100C. So this temperature is given for when the subject of ABs goes from being solid (solidified) to a stage where it deforms and loses shape (soft).

This means that ABS is particularly good for 3d printed parts that must have a certain durability, strength and flexibility - i.e. e.g. a functional prototype that could be used in a machine or an item that is otherwise exposed to high temperatures such as sunlight or hot liquids.

Solubility and Finish

ABS is soluble in acetone. Acetone is easily available and is a relatively safe chemical - which most women probably know as nail polish remover (note, however, that not all nail polish removers contain 100% acetone). Acetone can be used to treat/finish the surface of your 3d printed ABS item - here comes the explanation of a typical setup/treatment of an ABS item.

When you 3d print, you will typically be able to see the layers that the machine has made to build up the object (layer-on-layer). These layers can be easily treated with e.g. sandpaper, after which you can smear/treat the workpiece with acetone, so that the layers on the workpiece will fuse together - this will give a smooth surface as the many layers on the outside of the workpiece will fuse together and thus remove the visibility of the many small layers. To make full use of your acetone treatment, you can make use of acetone steam - we will get into this later. At the same time, we would like to point out that this is not something that should be experimented with at home, as acetone is toxic and must be treated by people with experience.

In other words, acetone vapor will give an or matt ABS printed item a high gloss and thus an often nice finish - however, you must also remember that it will be able to remove small details, as there is a melting of the outer shell of the item.

Disadvantages

One of the disadvantages of ABS is noticed when it is extruded / or heated, which is neither odorous nor, for that matter, recommendable to inhale.

Another disadvantage is that ABS material shrinks quickly after it is extruded. In this process where it is heated (expanded) and boiled down (shrinked), what is known as Warping often happens. This means that the subject contracts and thus loses its attachment to the subject plate on which the print is made. Warping is a known problem and there have undoubtedly been some good tricks for printing with this material over time. One of the things you can take into account is the substrate on which you print. We have great success printing on Kapton tape on a heated bed (110C) that is soaked/wiped in acetone juice (google this). This provides good adhesion. Another alternative is a BuildTak, which is basically a large sticker that is mounted on the subject plate where printing is done - it has a texture like a mouse pad and provides a good adhesion to your subjects - this applies to almost all materials within 3d printing. When you print with ABS, it can be an advantage to have a heated/enclosed build chamber - this can be done with acrylic sides or other enclosure of the printer, which means that the print in ABS has a slower cooling and thus avoids warping. You must be aware that when you run with a heated buildplate, it will cost significantly more in electricity and thus increase the price of your 3dprints. So there are both advantages and disadvantages to ABS that you should be aware of before you start printing.

+ Strength

+ Flexibility

+ Post-processing options

+Out end (often nice)

- Difficult to print with

- Warping

- Heated bed = more power

- Odor and pollution nuisance

PLA

PLA - or also known as Polylactic Acid - is a completely different form of thermoplastic. It is typically made from corn starch or sugar cane and is a biodegradable material - this means that it is a more eco-friendly material than ABS. It typically melts between 190 to 210 degrees Celsius and (defined by many) does not smell bad when melted - it is said that many people enjoy the smell of PLA, but we leave that unsaid.

PLA flows a little better than e.g. ABS, which roughly means that it has advantages when printing items with a high degree of detail and high speed - this is generally for PLA and there will of course be a difference from machine to machine - from software to software. PLA is known for being good at making sharp corners and is particularly known for not warping to the same degree as seen with ABS. As it does not warp to the same extent as ABS, it is also not necessary to print it on a heated bed, but can instead be printed on most substrates - glass sheets - build taks - masking tape - kapton - etc. Many use glue sticks, hairspray, wood glue, vinegar and many other fun things, get to increase the adhesion - at 3D Eksperten we only use BuildTaks and a clean cloth - and no greasy fingers or dust on the blank. It is often recommended to print at 60 degrees Celsius if you have a heated bed/heated workpiece plate installed.

When you print with PLA, you will quickly find out that it has a relatively glossy surface compared to ABS - the amount of gloss depends on the content (color) and partly on the print temperature used for the filament. Advanced users will often be able to vary its gloss by adjusting its print temperature - if this could be interesting to work on.

Solubility

PLA is not soluble in acetone, such as ABS. PLA, on the other hand, can be dissolved in Sodium Dydroxide (dishwasher tablet). These are very tough cases and not something you should get your hands on unless you know exactly what you are dealing with - So a "Dont do this at home" sign on this method.

So you have to print PLA at around 190-210C on the hotend and around 60C on a heated bed, tape or the like. PLA has a melting temperature (glass transition) of around 60C and deforms above these degrees. This means that PLA is not suitable for subjects that must be exposed to e.g. sunlight, hot cars or the like and is in its structure a "brittle" material and therefore not recommendable for many mechanical parts that must have a long durability. In other words, PLA is easier to print with for the normal user compared to ABS and one can conclude from this that PLA is more suitable as a "standard" material for the normal consumer of 3dprint, which must be used for "show-and-tell" topics, prototypes to be presented, etc.

+ Easy to print with

+ Good for sharp edges and corners

+ High level of detail and speed

+ Eco-friendly / Biodegradable

+ Does not smell bad / no requirement for ventilation

+ does not require a heated bed / better power consumption

- Fragile in structure (glass-like)

- Heat stability / deformation / low glass transition temperature of 60C

- Difficult to post-process (no acetone tricks)