LESSON 6.4 · 1:49 · CHAPTER 6 · CHOOSING AND HANDLING A MATERIAL
Porosity in two densities
Comparing printed and moulded density reveals the voids: a few percent to over ten percent in printed walls.
Predict · at 0:29 in the video
A carbon fibre PESU grade lists a specific gravity of 1.32 printed, and 1.46 moulded. What void fraction does that imply?
About 9.6 percent. 1.32 over 1.46 is 0.904. The rest, almost a tenth, is voids.
Further reading
This course is our own. These books go deeper.
- The economics of Big Area Additive Manufacturing, Post et al., Solid Freeform Fabrication Symposium, 2016
- Additively manufactured carbon fibre-reinforced composites: state of the art and perspective, van de Werken et al., Composites Part A, 2020
About the numbers
Simulations in this lesson are our own. Where a number rests on an assumption or a single source, the video marks it with an asterisk and says where it comes from.
Up next · 6.5 · 1:56Dry the pellets, size the hopper