The counter-rotating twin-screw is distinguished by the presence of two parallel screws rotating in opposite directions synchronously, giving rise to its characteristic name.

Structurally, the profile of the counter-rotating twin-screw is divided into several segments, each with a specific function in the plasticizing process. These include feeding, where the material enters the unit; compression, which reduces the volume of the material; plasticizing, which transforms the material into a malleable form; degassing, which eliminates trapped gases; and homogenization, which ensures a uniform consistency of the product.

The counter-rotating twin-screw offers significant advantages over the single-screw system. For example, it melts the material more effectively, thereby reducing energy consumption. Additionally, it is particularly suitable for processing complex materials, such as PVC, which require greater processing strength.

Regarding construction, the production of counter-rotating twin-screws requires a careful selection of materials, based on the quality of the material mix to be processed. Traditionally, nitriding steels are used, but depending on the specific needs, various types of welding overlays or H.V.O.F technologies can also be employed.