To ensure complete mold filling for thin-walled and other difficult to inject parts, mixed polyurethane resin and hardener are de-aerated. Next, the filled mold is placed in a pressure pot at 90-120 psi and 77ºF (25ºC) until fully cured. By curing the resin system under pressure, any bubbles that may form are compressed to a microscopic size that is visually undetectable.

Polyurethanes are well suited for pressure casting with a combination of such properties as:

• Easy handling with many systems that feature 1:1 or 2:1 resin to hardener mix ratios
• Gel times as long as 25 minutes at room temperature to accommodate the degassing, injection and installation of the mold in the pressure pot before the system begins to gel
• Formulations that accommodate pressure casting of thick-walled as well as thin-walled components