If you've ever looked in online stores for different filaments, you've probably come across the term PMMA. What exactly is behind it, what it can be used for and what advantages and disadvantages the 3D printing material has, we explain in this article. In addition, you get more info about the possible pressure and the melting temperature, the temperature of the heating bed etc.
Where can I buy PMMA filament?
Here is a small selection PMMA filament on Amazon:
* Stand: 2023-07-05 / Bilder: Amazon API
If this is not enough for you, then visit the following threedom subpage now:
PMMA Filament – What actually is PMMA?
The abbreviation PMMA stands for polymethyl methacrylate. This is a thermoplastic synthetic material. This is produced by substance polymerization from petroleum derivatives. The chamber procedure is used for this purpose. Many people know PMMA in its processed form as acrylic glass or Plexiglas.
PMMA filament is characterized by its good thermal properties, including high dimensional stability. Dimensional stability is maintained at temperatures of up to about 90 degrees Celsius or as low as -40 degrees Celsius. The finished material has an impact strength that is up to 17 times higher compared to conventional glass. This means that the material can also be used for demanding work. Other plus points of this filament are its high hardness and stiffness. Compared to normal glass, it has a light transmission of 92 percent. Later polishing can restore the optical purity.
What are the advantages of PMMA in 3D printing?
PMMA filament has some significant advantages over other materials. These include high impact resistance, long durability, its low flexibility and light diffusion. Since it is a transparent to almost transparent material, the finished printed object can also be colored later. From the manufacturer's side, it is also offered in different shades.
Another advantage is the high resistance to yellowing, which otherwise often occurs with UV radiation. The significantly lower weight is very positive – at least compared to glass. The filament is resistant to oils, gasoline and greases. For possible post-processing, it is important to know that PMMA is acetone soluble.
What are the disadvantages of PMMA filament?
PMMA is only moderately resistant to acids. Polar solvents, however, put a considerable strain on it. Furthermore, PMMA is known to like to warp. Therefore, we advise using a 3D printer that has a heating bed and – if possible – an enclosed build space. Otherwise, you can try to prevent warping by using a BuildTak plate (or cheaper: Pertinax plate as a permanent pressure plate). Special adhesive sprays or Blue Tape should also ensure better adhesion.
In our opinion, it is also a disadvantage that PMMA is classified as non-food grade.
Application examples for PMMA filament
PMMA is used in many applications. For example, the material is used for investment casting. The production of individual investment casting products used to take up to two months in some cases. For this purpose, wax was placed in a ceramic mold, which was then followed by alloy metal. The latter displaced the wax. These wax patterns are very expensive, with costs sometimes running into five figures. However, if 3D printing is used here and a material such as PMMA is used, it takes less than a week to produce a prototype of an object. The cost is only a few hundred euros, furthermore, this template may come up with a greater level of detail.
In addition to being used for investment casting processes, PMMA is
- As roofing material,
- For the manufacture of greenhouses,
- For the production of cell phone displays,
- In the field of dentistry for the production of dentures and bite splints (here also by means of 3D printing),
- For the production of housings and containers that do not have to be food-safe, as well as
- For jewelry making
used. For example, with the 3D printer you can print beautiful rings for your girlfriend or even relatives. Then for the packaging of the jewelry you might take a small tin printed from PMMA.
If you want a clear or transparent object that can withstand greater forces if needed, PMMA filament may be your material of choice.
What settings are used to print PMMA filament?
We would like to send in advance that the information given here are our experience values. These settings depend, among other things, on the 3D printer used and the composition of the PMMA filament.
- Printing temperature: 240 to 260 degrees Celsius,
- Temperature of the heating bed: 100 to 120 degrees Celsius,
- Printing speed: From 30 mm/s
Is a heated print bed (heatbed) required in the 3D printer for PMMA filament?
Since warping easily occurs when using PMMA filament, this should be prevented by using a heated print bed. Your 3D printer should also have a closed installation space.
Can PMMA filament be glued? If so, which adhesive is recommended?
As already mentioned, PMMA is polar and solvent soluble. Due to this, this filament can be glued particularly well. The transparent material in particular places some demands on the adhesive. Solvent adhesives have, among other things, the advantage of fast curing, but are only suitable for small areas.
With PMMA, polar solvents such as methyl ethyl ketone and acetone can cause stress cracking, so you should not use these agents for cleaning. Better bonding results are achieved with non-polar cleaners. These cleaners include isopropanol and n-heptane. Isopropanol should be allowed to flash off for a few minutes before applying the adhesive.
If you have 2-component adhesives at home that contain polyurethane, you can use them to bond the objects 3D printed with PMMA. Construction adhesives such as Scotch-Weld DP 610 bond transparent plastics, including PMMA to itself, but also to other plastics that include ABS, PC, PET, ES and painted and coated metal surfaces.
Objects made with PMMA can be glued very well with MMA adhesives. The abbreviation MMA stands for methyl methacrylate. However, as this material can lead to stress cracks on the surface depending on the PMMA formulation, it should be tested on a small area in advance.
For bonding, you can also use solvent-free 2-K construction adhesives that are acrylate-based. These also bond PMMA to various plastics, fiber composites, glass, wood and metal.
Highly recommended are 2-component construction adhesives that are epoxy resin-based. They exhibit good aging behavior and, in addition to PMMA, can also firmly bond other plastics, fiber composites and metals together. These adhesives are also ideal, above all, for heavily stressed bonded joints, for example on vehicles and machinery, as they can also withstand vibration and impact.
If you only have a small object made of PMMA to glue, you can also try superglue. Before doing so, however, you should test on a rather inconspicuous spot whether this adhesive is compatible with the material. Possibly, there may be a grayish coloration or visible streaks.
You can also use construction silicone to bond large, non-transparent objects. High-performance adhesive tapes are also suitable for bonding PMMA to various materials – including glass, PC, other plastics, metals, and even painted surfaces that are to be used indoors or outdoors.
This is how you should proceed when gluing the PMMA filament
Before you start gluing, you should first ensure your own safety. Therefore, put on special gloves. It would also be nice to protect your clothes from any solvent splashes with an apron. You should also ventilate the room well.
- First, clean the gluing surfaces with isopropanol. Make sure that the solution does not come into contact with the surfaces that will be visible later.
- Now fix the two workpieces to be glued. Between them should fit a thin piece of cardboard.
- Now let the adhesive you have chosen flow between the components to be bonded. At the bottom you can catch the excess remains with the cardboard already mentioned. Now let the adhesive cure on the components.
- If you don't want to fix the two halves in advance, you can also apply the glue to one of the pieces and then place the other piece on top.
How can PMMA filament be post-processed?
There are many ways to rework PMMA objects made with a 3D printer. If you want to drill holes in the object, they should not be too close to the edge. Otherwise there is a risk of chipping.
Highly recommended, among other things, machining finishing. However, as explained in the previous section, you also have the option of gluing the object. Welding is another finishing method. If the printed object has been transparent or translucent up to now, you can now color it. This makes it possible to achieve particularly interesting effects. Coloring is also recommended if, for example, unsightly color deviations have occurred due to bonding.
What do I have to pay attention to when storing PMMA filament?
Like all other filaments, you should store PMMA in a dry place. Although the material is relatively UV stable, you should still store it away from sunlight. The best way to do this is to use plastic bags, to which you add a few packets of silicate (also in the form of silicate litter*, which is also used as cat litter) and then seal them.
The silicate absorbs any moisture, keeping it away from the filament. You can then put the bags with the filaments in a plastic box, which is best closed with a lid, or in a cardboard box. The latter should also be able to be closed.