In the production process of polypropylene high-strength yarn, the drawing stage directly affects the strength and uniformity of the fibers. The polypropylene spinning drawing machine, as the core equipment for this process, is responsible for stretching and shaping the raw yarn, and is an important link that affects the quality of the finished yarn. 

The working principle and structure of the drawing machine

Polypropylene spinning drawing machines usually consist of multiple sets of heating rollers and cooling rollers. After the primary filament is extruded from the spinneret, it passes through different speed drawing roller groups one after another. Under the stretching effect of the hot rollers, the macromolecular chains are aligned axially, the crystallinity of the fiber increases, and the breaking strength also rises. By adjusting the speed ratio of each roller group, the drawing ratio can be controlled, thereby obtaining different specifications of polypropylene filaments. 

A complete drawing device also includes a guide wire device, a tension control device, a winding mechanism and a temperature control system. The surface of the drawing rollers is usually treated with hard chrome plating or ceramic spraying, which is wear-resistant and has a smooth surface, reducing the damage to the filament bundle. The temperature of the heating rollers is usually controlled between 100℃ and 130℃, and the specific value is adjusted according to the filament diameter and the drawing ratio. 

Key points for selecting Polypropylene spinning drawing machines:

When choosing a polypropylene stretching equipment, the following aspects can be considered: 

Number of stretching rolls: The common configuration is a six-roll or seven-roll system. More roll groups are beneficial for staged stretching and reduce the breakage rate. 

Temperature control accuracy: The temperature difference on the roller surface should be kept within ±1℃; otherwise, it may cause uneven stretching of the filament. 

Operating stability: The vibration and noise levels during the long-term operation of the equipment, which affect the uniformity of the filament bundle. 

Energy consumption performance: The models equipped with variable frequency speed regulation and efficient insulation design have lower electricity consumption per unit output. 

Daily maintenance and fault diagnosis of Polypropylene spinning drawing machines:

The key points of daily maintenance for spinning stretchers include: regularly cleaning the roller surfaces to prevent oil stains or polymer coking; checking the belt or gear transmission devices and replenishing lubrication in time; calibrating the temperature sensors to avoid excessive deviation between actual temperature and displayed value. Common faults such as filament entanglement, breakage or uneven stretching are often related to improper tension setting, roller wear or uneven heating. It is recommended to troubleshoot each issue separately.