What does RTM stand for and what characterizes the process?

What does RTM stand for and what characterizes the process?

• A. Resin Transfer Molding; resin is injected into a dry fiber preform inside a closed mold and cured under pressure.
• B. Rapid Transfer Molding; resin is injected into a dry fiber preform in an open mold at ambient pressure.
• C. Resin Transfer Method; resin is injected into a wet layup in a closed mold.
• D. Reactive Transfer Molding; resin cures before injection.

Answer: (A)

Resin Transfer Molding is a process where a dry fiber preform is placed in a closed mold and resin is injected under pressure to thoroughly wet the fibers. Once the preform is fully impregnated, the resin is cured in the closed mold to form a solid composite part. This combination of a dry preform, mold closure, and pressure-driven impregnation is what defines RTM and yields good fiber wet-out, low void content, and precise part dimensions. The other descriptions don’t fit because RTM uses a closed mold with resin injected under controlled pressure into a dry preform; it’s not an open-mold or ambient-pressure process. It’s also not a “wet layup” inside a closed mold, since RTM starts from a dry preform, and it isn’t cured before injection, as curing occurs after impregnation.

Resin Transfer Molding is a process where a dry fiber preform is placed in a closed mold and resin is injected under pressure to thoroughly wet the fibers. Once the preform is fully impregnated, the resin is cured in the closed mold to form a solid composite part. This combination of a dry preform, mold closure, and pressure-driven impregnation is what defines RTM and yields good fiber wet-out, low void content, and precise part dimensions.

The other descriptions don’t fit because RTM uses a closed mold with resin injected under controlled pressure into a dry preform; it’s not an open-mold or ambient-pressure process. It’s also not a “wet layup” inside a closed mold, since RTM starts from a dry preform, and it isn’t cured before injection, as curing occurs after impregnation.