Thermolysis of Injection Molded part

Question 1

What are the three extraction methods to remove organics before sintering the particle compact?

Answer 1

1) Thermal de-binding: volatilization in inert atmosphere or vacuum, or combustion in air (less residual carbon)

2) Wicking: pack the part in fine carbon powder. Low temp melting wax is drawn out of the part by capillary action. Powder and high temp melting binder provide support against slumping

3) Solvent extraction: part is immersed in a liquid in which one of the binders is soluble (ex: poltethylene glycol is soluble in water)

Question 2

What does the backbone binder do?

Answer 2

~ it retains the shape of the part, forming pendular bridges between particles

~ backbone binder is then thermally extracted