ASTM International’s additive manufacturing technologies committee (F42) is developing a proposed standard that will allow manufacturers to maximise the strength and quality of parts produced using the polymer additive manufacturing (AM) extrusion process.
According to ASTM member Rick Cole - a research officer at the National Research Council of Canada (NRC) and expert in composites manufacturing - the proposed standard (WK81710) will be used to assess the inter-layer weld in shear through a test that has been shown to provide repeatable results.
“It has been shown that the weakest areas of polymer AM parts produced using an extrusion process are formed between layers as material is deposited, also known as the inter-layer weld,” said Cole. “The properties of this weld have been found to be difficult to measure repeatably, for example, using tensile tests.”
According to Cole, the proposed standard will provide data that will be useful to part designers, manufacturing process developers, and quality assurance personnel.
“The good repeatability of the test in this proposed standard will allow users to fine-tune their manufacturing process, including setting printing parameters, to optimise the strength of printed parts,” added Cole. “Quality assurance personnel should find the test useful to verify the quality of a printing process on an ongoing basis.”
This effort directly relates to the United Nations Sustainable Development Goal #12 on responsible consumption and production.
“Increased use of the polymer AM extrusion process described in this proposed standard will help to eliminate the energy and materials required to manufacture tooling needed for traditional processes, such as injection moulding,” finished Cole. “The polymer AM process allows for the production of complex plastic parts without the use of tooling.”
