In the entire industrial chain of polypropylene filament production, the polypropylene spinning machine undoubtedly plays the role of the "heart". This highly integrated industrial equipment directly determines the key indicators such as the strength, fineness and uniformity of the final output fibers. Understanding the working principle and technical key points of the polypropylene spinning machine is of vital importance for improving product quality and production efficiency.

I. Core Principle: Precise control of melt spinning

The core process of the polypropylene spinning machine is melt spinning. The basic process is as follows: Polypropylene chips are put into the equipment, and after precise heating and melting, they become the spinning melt. Subsequently, under the high-precision control of the metering pump, the melt is stably conveyed to the spinneret. Finally, fine streams are extruded through the micro-holes of the spinneret, solidified and formed under the action of cooling air, and then drawn and wound into polypropylene filament. The entire process seems linear, but in fact, it has extremely high requirements for the stability of temperature, pressure and speed.

Ii. Equipment Composition: A precise systems engineering project

A modern polypropylene spinning machine is not a single machine but a precise assembly line, mainly consisting of the following systems:

Extrusion system: It includes a screw extruder, which is responsible for uniformly melting, compressing and conveying the raw materials. The accuracy of its temperature control directly affects the quality of the melt.

Metering and filtration system: The precision metering pump ensures a constant amount of melt output every second, which is the core to guarantee uniform fiber fineness. The melt filter is responsible for removing impurities to ensure continuous production.

Spinning box and spinneret: These are the "molds" for fiber forming. The pore size, shape and arrangement of the micro-holes on the spinneret directly determine the cross-section and characteristics of the fibers.

Side-blowing air cooling system: Uniform and stable cooling air is the key to the uniform solidification of the internal structure of fibers and the prevention of filament entanglement and breakage defects.

Stretching and winding system: By using multiple sets of high-speed rollers to stretch the nascent fibers, the macromolecular chains are oriented and crystallized, thereby achieving high strength. Finally, it is wound into a filament tube by a high-speed winding head.