First, a brief introduction to the three processes for making polypropylene BCF yarn:

The first one: one-step method: continuous spinning, stretching, deformation, winding process

The second method: two-step method: spinning and drawing combined → twisting or spinning winding → twisting and drawing deformation

The third method: three-step method: spinning and doffing → wire drawing → deformation

The one-step process for the continuous production of polypropylene BCF yarn requires the simultaneous use of three screws of the same specification to extrude the melts of the different colors required for the three requirements, and then pass through the distribution pipe to the spinneret, allowing each filament to be made up of three different The color of the silk is assembled, and finally the polypropylene BCF filament is made by continuous tensile deformation.

The two-step or three-step process is basically similar in that a winding bobbin is set to one color, and then the three color bobbins are combined and stretched to form a polypropylene BCF yarn.

Although there are three kinds of processes in foreign countries, the two-step process is used more.