This is a rubber or plastic material used as a seal.

This is a rubber or plastic material used as a seal.

• A. Polymer
• B. Ceramic
• C. Metal
• D. Elastomer

Answer: (D)

A sealing material must deform to fill gaps and movement, then spring back to maintain a tight seal as conditions change. This ability to undergo large, reversible deformation is the hallmark of elastomers. Elastomers are rubbery polymers with elastic recovery, so they can compress to seal tight spaces and rebound when pressure or temperature shifts occur, keeping leaks blocked. While polymers cover many plastics, not all plastics have the same elastic rebound, and ceramics or metals are too rigid to seal effectively because they don’t exhibit the soft, compliant deformation needed. So the material described as a rubber or plastic used as a seal is an elastomer.

A sealing material must deform to fill gaps and movement, then spring back to maintain a tight seal as conditions change. This ability to undergo large, reversible deformation is the hallmark of elastomers. Elastomers are rubbery polymers with elastic recovery, so they can compress to seal tight spaces and rebound when pressure or temperature shifts occur, keeping leaks blocked. While polymers cover many plastics, not all plastics have the same elastic rebound, and ceramics or metals are too rigid to seal effectively because they don’t exhibit the soft, compliant deformation needed. So the material described as a rubber or plastic used as a seal is an elastomer.