Materials for Large Scale Printing

Printable materials sit between two conflicting requirements: they must flow through a nozzle and then stop flowing immediately afterwards. Every formulation is a compromise on that single axis.

The printability window

We characterise mixes by open time, yield stress after deposition, and interlayer bond strength as a function of the delay between layers. The last of these is routinely under reported and is often the reason a laboratory formulation fails on site.

Reinforcement

Short fibre reinforcement improves tensile behaviour but narrows the printability window considerably. Continuous reinforcement placed in a separate pass keeps the window open, at the cost of a more complex machine.