We need to get testing done on the strength properties of a printed part in this material using our standard settings.
Got a response back from a test lab in Denver. They had some questions they wanted clarified. I gave them answers enough to get a quote prepared, but we do need to clarify some other things before moving forward.
- Most notably they wanted to know what form the data should be delivered in. Understanding that the more they need to collate and calculate the data the more expensive the testing will be, they mentioned tabulated data sets, standard deviation amidst samples, stress/strain curves (full and partial range). All these options are determined by how we need to present the data to our users/customers. I think that (since strength is so dependent on model geometry, material condition, and profile settings) we want the tabulated values with maybe the standard deviation among samples. This would allow us to claim "up to" strength numbers without potentially incurring push-back when delicately printed parts or parts printed with improperly stored materials don't live up to the strength figures.
- They also wanted to know which standard the testing needed to be done to. Without that disclosed on the TDS from the supplier we cannot match testing methods. ASTM D638 is the standard plastic tensile strength testing standard. Although the test engineer is going back to see if there is another standard that fits better, we will likely use this standard.
- They are willing to disclose a basic overview of the testing methods within the results they deliver as well as getting us the link to where the ASTM documentation and standards are. This could allow a one stop disclosure of all relevant information.
- They are willing and able to to impact testing as well as tensile strength testing. Is this something we need? If so, which test method: Izod or Charpy V-Notch Impact testing?
ASTM D638 for tensile strength, elongation at break
ASTM D256 for Charpy impact strength
Also Glass Transition Temperature (not sure of test, but some refer to slope of temp increase to determine as 10 deg C per minute