All across the world, innovative minds are working to further enhance 3D printing technology and materials. In Russia, this movement is being pioneered by REC 3D, producers of high quality filaments for FDM 3D printing. With a wide range of ABS, PLA, HIPS, and other unique types of materials, the Russian filament producer and 3D printing service bureau has solidified itself at the forefront of the country’s growing market.
As a whole, when it comes to additive manufacturing, Russia is looking beyond basic prototyping and 3D printed Yoda heads. The state-owned nuclear energy company ROSATOM recently developed a state-of-the-art metal 3D printer, while Russian astronauts have experimented with printing living tissue in space. But when it comes to FDM 3D printing technology, REC is leading the way with their high quality materials and all-encompassing 3D printing services.
REC realizes that in order to continue improving the capabilities of this emerging technology, users must have access to adequate knowledge on the mechanical and aesthetic features of 3D printing materials. Thus, the filament producer has recently created a comprehensive report about stress testing their materials.
The test, exclusively shared with Filaments.directory, focuses on mechanical characteristics like flexural deformation, tensile strength, elastic modulus, and more. In the report, REC experiments with their REC PLA, REC ABS, REC HIPS, REC RELAX, REC ETERNAL, as well as their flexible materials REC FLEX and REC RUBBER. The advanced study is packed with informative illustrations and critical data on the REC material product range.
In an industry with an overload of materials and an underwhelming amount of information, reports the like REC stress test are extremely helpful for makers and 3D printing enthusiasts searching for the functionally ideal material to use with specific applications. Without further ado, Filaments.directory would like to share the “REC: Stress testing 3D printing materials” report. Check it out below!
- Hello there. What’s all this?
- Those are 3D printed parts.
- Well then, are they any good? Can you print me a house or a car?
Lemme see how strong they are… *SNAP!*Ha! Couldn’t handle it!
I gotta say that’s rather disappointing. Good for toys, maybe, that’s about it.
Have you ever had a run in with people intent on stress-testing everything with theirbare hands? It happens to us all the time. Even if a part stands up to abuse, such experimentsdo little to answer the question of durability, since the amount of force applieddiffers from one skeptic to another. Our company has a long-standing reputation forthorough material property research, so we figured it was time to settle the matter onceand for all!
We have decided to go all the way and give definitive answers to questions regardingflexural, tensile and compressive strengths of our materials. However neat-picky wemay be in general, this time it was decided to leave no stone unturned and seek assistancefrom the Center for Testing, Certification and Standardization of Functional materialsand Technologies. The center was founded with support from several stateresearch companies, Government of Moscow and Moscow State University (MSU). Itsmain purpose is to provide small and medium businesses in Moscow with certificationand product testing in compliance with modern standards.
The center features state of the art equipment and is staffed with highly-qualified personnel,many of whom are MSU’s top chemistry graduates. That said, we can be certainof results – these guys get their numbers right no matter what!
In our case testing was carried out on a Tinius Olsen 300ST – electromechanical universaltesting machine used to measure tension, compression, flexure and shear strength.The brand Tinius Olsen is so popular it has become something of a generic trademark.These machines set the standard for material testing since the 19th century. This iswhat this beauty, a product of Scandinavian ingenuity, looks like:
A lot more impressive than eager for destruction hands of the passerby, isn’t? A demonstrationcan be found on the Tinius Olsen official Youtube channel – just follow this link
Next we should go back to our well-forgotten high school physics lessons and try to recalldefinitions of relevant properties. Those of you with good memory or dealing with theseterms on regular basis may skip the next part. Note: Since we want to keep this as shortas possible, definitions have been simplified to fit our case.
Flexural deformation describes bending or twisting of test bars along a given axis withcomparative measurements taken at the ends and in the middle.
Tensile and compressive deformation describes elongation or compression by applicationof force along longitudinal axis through the center of mass.
Strength measures resistance to destruction due to inner stresses, caused by outsideforces. Basically, this is the characteristic that defines a material’s ability to do its jobunder a load over prolonged periods of time without breaking.
Elastic modulus measures the ability of a solid body to deform elastically (i.e., non-permanently)when forces are applied to it.
Maximum load is the value of maximum force applied to an object during testing. This isthe value that describes the limit of applied force before inner stresses cause an object’sdestruction or irreversible deformation.
Compressive and tensile strengths describe the limit of variable mechanical stress,surpassing which will cause a test sample to be crushed, torn apart or permanentlydeformed.
Got all that? Well done! Now that we have figured out our goals, looked at testing methodsand the equipment, it is time to proceed to actual results.
PART 1. FLEXURAL TESTING
Test samples consisted of 3 mm thick, 13 mm wide and 60 mm long bars (0.12х0.5x2.36in.). Testing was carried out using standard test methods for flexural properties of unreinforcedand reinforced plastics and electrical insulating materials (ASTM D790 – 03).
As it turns out, REC PLA is the hardest, followed by REC RELAX with a difference of 18MPa, then REC ETERNAL, REC ABS and finally REC HIPS. Naturally, maximum load valuesare directly proportional to hardness.
It should be noted that flexible materials for obvious reasons should be looked at from adifferent standpoint, therefore REC FLEX and REC RUBBER shall only compete with eachother.
PART 2. TENSILE TESTING
Test samples consisted of double-ended 3D printed paddles 3 mm thick, 13 mm wideand 165 mm long (0.12х0.5x6.5 in.). Testing was carried out using the standard methodfor tensile properties of plastics (ASTM D638 – 14).
This time top honors went to PET-G based REC RELAX, closely followed by slightly lessresistant REC ETERNAL and REC PLA.
PART 3. COMPRESSION TESTING
This stage involved 3D printed cylinders 12.5 mm in diameter and 25.5 mm in height(0.5x1 in). Testing was carried out using the standard method for compressive propertiesof rigid plastics (ASTM D695 – 15).
REC PLA has come out on top once again, surpassing ETERNAL by a factor of 1.4 andproving to be time and a half more resilient to compression than RELAX. Not bad!
Finally, we’d like to offer a comparison of injection molded parts versus 3D printed onesmade of ABS plastic. This should clear up the matter of comparative strength (data wasacquired here: http://himcompany.com).
Let’s sum up all of the above:
- REC PLA
- REC RELAX
- REC ETERNAL
The most resistant to elongation are:
- REC RELAX
- REC ETERNAL
- REC PLA
The most resistant to compression are:
- REC PLA
- REC ETERNAL
- REC RELAX
3D printed ABS parts are just as resistant to compression and flexing as injection molded ones, but are inferior in terms of tensile strength. Elastic modulus of 3D printed samples reaches 75% that of molded parts.
That is all for today, hopefully this information will prove useful to all the makers out there – now or in the future! Should anyone be interested in a detailed review or earlier tests, additional information can be found at our new site – rec3d.ru.
REC: We’ll be happy to answer any questions! Give us your comments, write an e-mail, call or send a message through a social network. And don’t forget that our office doors are always open to visitors. There is a lot of interesting stuff on display at our showroom!
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Please visit our interesting instagram channel where you could find a lot of 3D printed cases printed with our materials and just for meeting with our company: www.instagram.com/rec3dcompany