What is the primary purpose of vacuum forming?

The primary purpose of vacuum forming is to shape sheets of polymer over a pattern. This manufacturing process involves heating a plastic sheet until it's pliable, then using a vacuum to draw the heated sheet over a mold. The vacuum removes air between the sheet and the mold, allowing the plastic to conform tightly to the shape of the mold as it cools and solidifies. This method is widely used for creating various products, such as packaging, trays, and containers, due to its ability to produce detailed shapes efficiently.

The other options do not align with the main functionality of vacuum forming. For instance, joining two metals is a welding or soldering process, which is distinctly different from shaping plastics. Creating plastic sheets refers to the initial manufacturing of polymer materials and does not encompass the shaping process that vacuum forming performs. Producing gas mixtures for welding pertains to a completely different area of engineering that deals with welding techniques and applications, and is also unrelated to the specific process of vacuum forming.