How to heat a tow
Heat is what makes a tow stick (thermosets) or weld (thermoplastics), and four kinds of heater compete to deliver it at the nip: hot gas (cheap, hard to control), infrared (radiant, spreads wide), laser (focused, hot, needs safety), pulsed light (targeted, controllable, both material families). Whatever the heater, heat is coupled to speed: at fixed power the energy per millimetre of tow is P/v, so go twice as fast and each millimetre gets half the energy.
Predict · at 2:18 in the video
Now a question. Keep the heater at the same power and double the head's speed. What happens to the tow's temperature?
It drops. The heater pours out the same energy every second, but now that energy is spread over twice as much tow. Each millimetre gets half as much.
Automated Fiber Placement: Status, Challenges, and Evolution, Ramy Harik & Alex Brasington.
- Chapter 2, section 3.A
- Chapter 2, section 3.B
- Chapter 2, section 3.C
Simulations in this lesson are our own. Where the numbers are invented to show a mechanism, the video says so on screen.
