Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Primary Reasons for Vacuum Degassing Urethane Resin

1.Air entrapment during mixing — Urethane resins are typically two-part systems (resin and hardener). Stirring them together introduces microscopic air bubbles, which become trapped due to the material's viscosity.

2.Moisture sensitivity — Polyurethanes react with moisture (from humidity or contaminated components), leading to bubbling, foaming, or tiny surface bubbles if not controlled. Degassing helps mitigate issues from minor moisture exposure.

3.Volatile components — Some formulations contain volatiles that can contribute to gas formation under certain conditions.

What Happens If You Don't Degas?

1.Bubbles remain in the cured part → causing visible defects like voids, pits, nodules, or cloudy appearances (especially in clear/translucent castings).

2.Weakened mechanical properties → reduced strength, tear resistance, and overall integrity.

3.Surface imperfections → rough texture or deformities that require post-processing or render the part unusable.

Benefits of Vacuum Degassing

1.Produces bubble-free, high-clarity castings with smooth surfaces.

2.Improves material flow and mold filling, especially in complex geometries.

3.Enhances physical properties like tear strength and durability.

4.Essential for optical clarity in transparent urethanes or high-quality prototypes/production parts.

Additional Notes

1.Degassing is often combined with pressure potting (after pouring) for even better results, as pressure compresses any remaining tiny bubbles.

2.Not all urethanes require it (e.g., very low-viscosity or slow-cure types may release bubbles naturally), but it's standard best practice for professional results.

3.Fast-curing resins may have limited time for degassing, so equipment with quick pull-down is recommended.

This process ensures reliable, high-quality urethane castings suitable for prototyping, low-volume production, or artistic applications.