Tyhjiömuodostuksessa

Tyhjiömuodostuksessa, often translated as vacuum forming, is a manufacturing process used to create three-dimensional shapes from a plastic sheet. This technique involves heating a sheet of plastic until it becomes pliable, then stretching it over or into a mold. A vacuum is then applied to one side of the plastic sheet, forcing it to conform to the contours of the mold. Once the plastic has cooled and solidified, it is removed from the mold as a finished part.

The process begins with a flat sheet of thermoplastic material. This sheet is clamped onto a frame and positioned above a mold. Heating elements, typically infrared, are used to evenly heat the plastic to its softening point. The temperature and heating time are critical to ensure the plastic is malleable but not so hot that it degrades.

After sufficient heating, the plastic sheet is brought into contact with the mold. A vacuum pump is then activated, creating a pressure difference that draws the softened plastic down and into intimate contact with the mold surface. This vacuum pulls the air out from between the plastic and the mold, ensuring a precise replication of the mold's details.

Once the plastic has cooled and hardened, the vacuum is released, and the formed part is ejected from the mold. The excess plastic around the edges, known as the flange, is then trimmed away. Vacuum forming is a cost-effective method for producing relatively thin-walled parts in large quantities and is suitable for a wide range of plastic materials, including polystyrene, ABS, and PET. It finds applications in packaging, automotive components, signage, and consumer goods.