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3D printer: which filament for which purpose?


3D printers melt plastic from filament rolls and layer it into models. We show different materials and give tips for beginners.

The first 3D printers processed filament made of acrylonitrile-butadiene-styrene (ABS). The material is stable but not easy to print: processing is practically impossible without a heated print bed and a closed installation space. This drives up the costs for the printer and raises the entry hurdle. Later, the easier-to-print polylactide (PLA) began its triumphal march, but it is far more sensitive to breakage. The market now offers a number of different materials with different advantages and disadvantages.

But that’s not all: Even filaments from different manufacturers are quite different – despite the same name. Even filaments from one manufacturer have slightly different properties depending on the color. For perfect printing, it is therefore always necessary to find the optimum in terms of settings.

If you store filament, it should be stored as cool, dark and above all dry. In practice, storage in airtight zip bags and the use of dry granules has proven to be reliable, because some of the plastics pull water over time and can then no longer be processed well.

If you are just beginning your 3D printing experience and are simply looking for a reasonable filament at a good price, you can find the tips in the “For Beginners” section.

The key data for the print settings can be found in our overview of the materials presented:

Filament overview

material

PLA

SECTION

PETG

TPU (Flex)

Wood

Printing temperature

160-220 ° C

210-250 ° C

210-250 ° C

190-245 ° C

175-250 ° C

heated print bed

not necessary

80-110 ° C

0-75 ° C

0-60 ° C

not necessary

Cooling required

Yes

No

recommended

recommended

recommended

stability

*

**

***

***

*

Heat resistance

*

**

***

**

*

Toxins

not food safe

toxic fumes when printing

food safe

not food safe

not food safe

Polylactide (PLA), also called polylactic acid, is one of the most common materials for 3D printers. This is mainly due to the relatively uncomplicated processing and the low price. In addition, every FDM printer can handle it, since it does not require a heated print bed. Examples of affordable models are the recently tested Da Vinci Mini w + (test report) and Duplicator i3 Mini (test report).

The biodegradable thermoplastic is made from renewable resources such as sugar cane, corn starch or potato starch and not from petroleum. PLA is also used in the medical field: implants, for example, dissolve within a few years and are converted into harmless lactic acid in the body. However, this only applies to pure PLA. Colorful filaments for 3D printers are mixed with various colors and additives; their exact chemical composition is usually a secret of the manufacturers. So PLA is suitable Not For printing cups, bread boxes or similar objects that are to come into contact with food.

Very affordable printers, such as the recently tested Duplicator i3 Mini, do not have a heated print bed and are primarily suitable for PLA.

PLA prints are sturdy but brittle. The melting temperature is relatively low at 160 to 220 degrees Celsius. The print also works on unheated print beds, but if you want to use a heated print bed, you should set its temperature to 50 to 60 degrees Celsius. Since the material cools slowly, a fan should run during printing. This cools the filament and thus ensures a better printing result. Although odors develop during the printing process, they do not produce any toxic fumes. The pressure can therefore also take place in living rooms without exhaust air.

Disadvantages of 3D printing from the filament are, in addition to the brittleness already mentioned, poor heat resistance: the normal PLA softens from a temperature of 45 to 60 degrees.

One solution is based on PLA-based special shapes such as PLA Plus, PLA Tec, Impact PLA, HD PLA, Biofusion, PLActive or Polymax. They promise an unproblematic printing process and special properties such as high temperature resistance, high strength or even antibacterial surfaces.

The use of sandpaper or spray spatula is recommended for finishing. For example, superglue is suitable for gluing.

In addition to single-color rolls, special shapes made of PLA are also available. For example, there are semi-transparent, glittering or afterglow filaments. There are also variants with color changing properties when exposed to heat or UV radiation. However, the special variants do not only have advantages. When processing afterglowing filament, for example, the wear of the nozzle is significantly higher than with normal PLA.

Acrylonitrile butadiene styrene (ABS) is one of the most widespread filaments alongside PLA. It is durable and inexpensive, but a bit demanding in terms of processing: a heating bed and a closed installation space are necessary for printing.

ABS is a petroleum-based plastic and therefore not biodegradable. Toys such as Lego bricks, but also automotive components or pipelines as well as helmets are often made from this material.

It is very impact-resistant, but still somewhat elastic and also heat-resistant up to around 100 degrees Celsius. The optimal printing temperature is between 210 and 250 degrees Celsius. A heated print bed with a temperature of 80 to 110 degrees Celsius is necessary for adhesion. Until a few years ago, cheap printers did not use this feature. In the meantime, inexpensive printers, such as the Tronxy X5SA (test report), have also been equipped with it.

ABS cools down quickly. The use of a closed installation space is advantageous, so that new print layers can be printed on still warm filament. Since most affordable printers only have an open case, this is difficult. Self-made enclosures for 3D printers (building instructions) are a good and cheap solution to the problem.

Active cooling by fans is not necessary. Toxic vapors are produced when the plastic is printed, which is why the room in which it is printed should be well ventilated. If you print a lot with the material, you should get an extraction system.

Sanding paper or steaming with acetone are ideal for reworking ABS. Acetone attacks the plastic and softens it. The result is a smooth surface; individual print layers are no longer recognizable. More Information on processing with acetone is available here. Either superglue or special plastic glue, such as Uhu Plast Special, is used for gluing.

The material is available in numerous colors, including luminescent or semi-transparent ABS.

Glycol modified polyethylene terephthalate (PETG) is a relatively little-used plastic in 3D printing. According to the manufacturers, the material combines the advantages of PLA and ABS. Specifically, this means that it is relatively easy to print and still robust.

In its basic form, we encounter polyethylene terephthalate (PET) every day in the form of plastic bottles for drinks. The modification with glycol ensures that the material has better processing properties for 3D printing. An advantage over other materials is the high transparency and durability.

The synthetically produced filament is more impact-resistant than ABS and heat-resistant up to around 90 degrees Celsius. The printing takes place at temperatures of 210 to 250 degrees Celsius. A heating bed with a temperature of 40 to 75 degrees Celsius is necessary so that the individual layers of print adhere reasonably to one another. Active cooling is recommended.

PETG tends to pull strings. These can be ground down. Flat gluing is achieved with super glue. A great advantage of the material is the weather resistance and the fact that the filament does not draw water and is food safe. If you want to print lunch boxes or cookie cutters, you should use PETG.

In addition to semi-transparent versions, filaments in neon colors or metal optics are also available. It is possible to print almost transparently. The key is to feel your way around the ideal settings and play with the printing speed and temperature. The result is milky to almost transparent objects.

Thermoplastic polyurethane (TPU), an elastomer based on urethane, behaves similarly to rubber. The material is suitable for, among other things, shock absorbers and protective housings.

However, printing with this material is problematic due to the high elasticity. In printers with a Bowden cable feed, processing usually only works after hardware modifications. These stand for popular printers, such as the Ender 3 (guide) free print template to disposal. If you still want to try out the material, you should only order a small amount for testing as a precaution and inquire in advance whether your printer can handle flex filament.

The advantages of TPU are high resistance to chemicals, high abrasion resistance and low odor. The material is non-toxic, allergy-friendly and skin-friendly. It is also UV-resistant and has a high weather resistance.

Depending on the manufacturer, the pressure temperature varies between 190 and 245 degrees Celsius. The use of a heated print bed at 60 to 90 degrees Celsius is advisable, but the print works without a heated bed. The use of a fan to cool the pressure makes sense and is recommended.

The selection of colors is large, but they look far less gaudy than with other materials. Milky-transparent TPU is also available.

Wood filament prints have a very special charm. Not only that the finished objects really look like wood and can be processed in this way, the wood scent during printing also has its charm.

In most cases, the filament consists of a proportion of real wood particles and the PLA described above. The printing properties are therefore similar to that of PLA.

Image:

Some manufacturers, such as xyzprinting, have filament constraints. Foreign filaments only work with trickery.

Processing works with most printers, since no heated print bed is required. The extruder temperature is between 175 and 250 degrees Celsius. Color differences can be created by temperature differences: the warmer the print head works, the darker the finished result. You can even display a wood grain.

The advantages of the material are the natural smell, a natural feel and easy post-processing. Print results are easy to grind, glue and drill. The disadvantages are poor stability, no resistance to chemicals and the fact that the filament draws water. The finished print would swell in the water and lose its shape.

The material is available in shades of brown from beige to almost black. Green tones are now also available.

If you have no experience with your 3D printer, you want to start printing without wasting a lot of money. For first attempts, the filament should be cheap and easy to work with, but still give decent results. This is where PLA comes in. Although it is less resistant than ABS or PETG, it is much easier to handle. If in doubt, the handle to PLA-based special shapes with special properties helps.

Our experience shows that filament should not be too economical. Cheap filament is not automatically bad, but there is a risk of processing problems.

A good example of such a cheap filament is the Owl material. A kilo of PLA from the manufacturer costs just 10 to 15 euros. The competition demands significantly more with 20 to 40 euros per kilo. The main problem with Owl is the extreme fluctuations in quality. These are noticeable, for example, in the filament diameter. If this is uneven, blockages or over-extrusion occur. Filament winding can also be problematic. If the material is not properly wound up on the roll, the material flow suffers. In the worst case, knots form and the material breaks. The result is canceled prints and angry users. Whether you get good or bad material is a matter of luck.

We therefore recommend investing a little more and choosing a proven brand. For example, we have had good experiences with the brands in recent months Eryone, Extrudr, Geeetech and 3DJake made. Even the relatively cheap Amazon basics filament is recommended.

Filaments differ among other things in colors and printing properties. The different materials and their properties are particularly suitable for very different purposes.

For prototypes and model building, the use of easy-to-process PLA is usually sufficient. If you have a heated print bed and attach more importance to durability, you should use ABS. If there is no heating bed available and the print result should still be stable and heat-resistant, it is worth taking a look at the PLA variants PLA Plus, PLA Tec, Impact PLA, HD PLA, Biofusion, PLActive or Polymax.

If you want to print semi-transparent covers for lamps or waterproof vases, go for PETG. Plastic is also the first choice for items that come into contact with food.

TPU or related filaments can be used to protect your Actioncam or to use vibration-damping properties. The processing does not work with all printers.

When printing decorative items, it is worth taking a look at the filaments with the addition of real wood. These have a pleasant feel and look very good. Post-processing is not a problem, but the stability is only mediocre.

Numerous other filament exotics (guides) are available for special applications. The selection ranges from nylon and stone filament to water-soluble materials. You can find more information on post-processing of printed products in the guide: Smoothing, varnishing & post-processing 3D prints.

If you are not sure whether filament is the most suitable printing material, you should read the guide UV resin or plastic filament: 3D printer comparison.


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