What Is Melt Spinning?

Melt spinning is a molding method that uses a polymer melt as a raw material and uses a melt spinning machine to spin. All polymers that can be melted or transformed into a viscous fluid state by heating without significant degradation can be spun using the melt spinning method.

Melt spinning, also known as melt spinning, is a molding method that uses a polymer melt as a raw material and uses a melt spinning machine. Any polymer that can be melted or transformed into a viscous fluid state without significant degradation can be processed by melt spinning

The principle of melt spinning is shown in the figure below.

During melt spinning, the bulk polymer is melted in the screw extruder and sent to the spinning position. It is fed into the spinning assembly by a spinning pump. After filtering, it is extruded from the capillary holes of the spinneret. The liquid filaments gradually solidify as they pass through the cooling medium, and then are drawn into filaments at high speed by the winding device below. The filaments are primary fibers, and the primary fibers are post-processed into fibers. In order to prevent the filaments from cooling too fast and difficult to form filaments, isothermal melt spinning is sometimes used, that is, an isothermal greenhouse is added to the spinneret (called the spinning tunnel). The stretching speed of the winding device is very high, which can reach 1500 ~ 3000 m / min, depending on the type of material and rheological properties. The draw ratio of melt spinning is large, the yield is very high, and it can be adjusted within a wide range. Polyester (polyester fiber), nylon and polypropylene fibers are all formed by melt spinning.

The main process parameters of melt spinning include extrusion temperature, mass flow rate of polymer through the holes of the spinneret, winding speed or doffing speed, cooling conditions of the spinning line, the shape and size of the spinneret, and the spacing, spinning process Length, etc. This method is suitable for polymers that can be melted, easy to flow but not easily decomposed, such as polyester, polypropylene, and nylon. ^[1]