Cross-section of a plastinated human head
When bodies are plastinated, a technique pioneered by Gunter von Hagens in 1977, the body is first treated with formaldehyde, similar to an open-casket funeral, but at a higher concentration.The veins and arteries are injected with red and blue plastics.
The body is then dissected in any way required for the planned exhibit or sale piece.
After dissection, the specimen is placed in an acetone bath its temperature is lowered to below the freezing point of water, but above the freezing point of acetone. When the water in the cells expands due to freezing, it’s drawn out of the cells, and it’s replaced by acetone.
When all of the tissues are impregnated with acetone, the body is placed in a bath of polymer or plastic resin, and placed into a vacuum. Because acetone has an already-low boiling point, putting it into a vacuum causes it to boil at room-temperature, while still in the cells. The vaporization of acetone in the tissues leads to a negative pressure, which draws the polymer into the empty spaces.
After the body is fully infused with the polymer, it’s posed as it will be in its final form and cured (with gas, UV light, or heat) according to what it’s infused with, and hardened in place.
Plastination from Gunter von Hagens