As a core equipment in the production of chemical fibers, the functional area design of Polypropylene yarn stretching machines directly determines the strength, uniformity and production efficiency of the fibers. Through the coordinated operation of multiple functional zones, this equipment has achieved a complete transformation from raw materials to high-strength polypropylene filament.

The melt extrusion zone is the primary functional area of the Polypropylene yarn stretching machine. This area heats polypropylene resin to a molten state through a screw extruder and uses a pre-filter to remove impurities to ensure the purity of the melt. The melt then enters the spinning box and forms fine filaments through rectangular or circular spinnerets. This process requires precise control of temperature and pressure to avoid local overheating or incomplete penetration, thereby ensuring the stability of the cross-sectional shape and diameter of the fibers.

The stretching and setting zone is the key to enhancing the strength of fibers. Polypropylene yarn stretching machines are usually equipped with 3 to 5 pairs of drawing rollers. Through step-by-step stretching, the molecular chains of the fibers are arranged in an orderly manner, significantly enhancing their strength and elasticity. For instance, the DHP419 series equipment of Jiangxi Donghua Machinery adopts an efficient stretching device, which can achieve a single filament strength of over 7.0g/D. Meanwhile, the equipment precisely controls the setting temperature through hot rollers and insulation boxes to ensure that the fibers maintain stable physical properties after stretching.

The cooling oiling zone is responsible for the rapid cooling and surface treatment of the fibers. The side-blowing device blows the cooling air evenly towards the fibers, enabling them to cure rapidly. The oiling system, on the other hand, applies lubricants to the fiber surface through spray or oil rollers, reducing frictional damage during subsequent processing. Some of the equipment also adopts atomizing nozzle technology, accelerating cooling with water mist at around 40℃ to further enhance the rigidity of the fibers.

The functional area design of the Polypropylene yarn stretching machines reflects the characteristics of high efficiency, precision and energy conservation. By optimizing the synergy of each functional area, the equipment can stably produce high-strength polypropylene filaments ranging from 300 to 1800 denier, which are widely used in industrial sewing threads, hoisting ropes, geotextiles and other fields, meeting the market demand for high-performance fibers.