Which polymer forming process uses a heated sheet drawn into a mold by vacuum?

Which polymer forming process uses a heated sheet drawn into a mold by vacuum?

• A. Vacuum forming
• B. Line bending
• C. Thermoforming
• D. Calendaring

Answer: (A)

In this process a heated plastic sheet is softened and then pulled into a mold by suction. The vacuum pulls the sheet into the cavity, forming a hollow shape as it cools. This is vacuum forming, a specific technique within thermoforming that uses suction to shape the part. Thermoforming in general covers heating and shaping sheets, which can be done by vacuum or by pressure, but the key feature here is drawing the sheet into the mold with a vacuum. The other methods don’t involve pulling a heated sheet into a mold: line bending uses a heated line to bend sheet sections, and calendaring passes material between rollers to make thin sheets or coatings. Vacuum forming is especially common for trays, enclosures, and simple hollow parts.

In this process a heated plastic sheet is softened and then pulled into a mold by suction. The vacuum pulls the sheet into the cavity, forming a hollow shape as it cools. This is vacuum forming, a specific technique within thermoforming that uses suction to shape the part.

Thermoforming in general covers heating and shaping sheets, which can be done by vacuum or by pressure, but the key feature here is drawing the sheet into the mold with a vacuum. The other methods don’t involve pulling a heated sheet into a mold: line bending uses a heated line to bend sheet sections, and calendaring passes material between rollers to make thin sheets or coatings. Vacuum forming is especially common for trays, enclosures, and simple hollow parts.