Filament types

The three most established 3D printing techniques for plastic parts are stereolithography (SLA), selective laser sintering (SLS) and fused deposition modeling (FDM). In the workshop I have a Prusa i3 MK3S+ 3D printer at my disposal. This uses the SLA technique and prints the objects by heating a thin plastic wire, the so-called filament. In addition to different colors, there are also several different types of filament. Each with its own specific properties and areas of application.

PLA

The abbreviation PLA stands for PolyLactic Acid and this material is often used as an alternative to plastic. PolyLactic Acid is available in different colours, but has a naturally transparent appearance. Color can be added by adding color pigments to the material.

PLA is made from starchy plants and is a thermoplastic. PLA is biodegradable and comes from, for example, corn plants, sugar cane or sugar beet. This makes PLA a more environmentally friendly material than, for example, ABS, which is made from fossil fuels. Because PLA is a strong and easy to use and environmentally friendly material, it is a popular choice for use in 3D printers.

rPLA

Recycled, Reflow or Reform rPLA is a recycled PLA type 3D printer filament that is made from extrusion waste or other residual material during the manufacturing process of the regular PLA filaments. Although normal PLA is already biodegradable, rPLA is in principle an even more sustainable choice. Because sometimes colors can be mixed, this material sometimes has surprising colors. There are even filaments that give a 'rainbow' effect to the object after printing.

In terms of product properties, this material is 100% comparable to the normal PLA filament. The material, and therefore the final printed object, sometimes has a slightly more matted surface than normal PLA

PETG

The material of the well-known PET bottles. Polyethylene terephthalate glycol, known as PETG or PET-G, is a thermoplastic polyester that offers significant chemical resistance, durability and formability for manufacturing. PETG is an adaptation of PET (Polyethylene Terephthalate) where the 'G' stands for glycol, which is added at the molecular level to provide different chemical properties. PET uses the same monomers as glycol-modified PETG, but PETG is stronger and more durable, more impact resistant and better suited for higher temperatures.

The surface of PETG material is usually more shiny than PLA material, which more often has a satin sheen. Therefore, the PETG material is also more common for objects that must remain transparent or translucent.

PVA

PVA is a generally transparent water-soluble filament for making removable support structures. Overhanging parts of the object to be printed can be supported during the printing process. Afterwards, this 'support' will then be removed.

However, PVA is relatively expensive and only of limited use with printers with only one print head because changing filaments during printing is expensive and time-consuming. Personally, I hardly use the material for this reason. All the more so because the necessary 'supporting construction' can usually just as easily be printed from the original printing material. My printer is able to cool this material slightly more when applying, so that it adheres less well to the final object and can therefore be easily removed afterwards.