The two core issues regarding the purchase of Polypropylene double-twist yarn! 

Polypropylene double-twist yarn (high-strength polypropylene double-twist yarn) is a type of yarn formed by twisting and combining two or more strands of polypropylene filaments. It is widely used in webbing, industrial fabrics, sewing threads, cable ropes, and other fields. Many purchasers often encounter confusion when selecting models: for the same type of double-twist yarn, some have knotting and arching during weaving, while others have uneven strength. Let's address two common issues below to help you clarify your thinking. 

1. Twist and Twist Direction: Where does the origin of twisting occur during weaving? 

Twist (the number of twists per meter) and twist direction (S twist or Z twist) are the core parameters of double-twist yarns, directly influencing the strength and weaving performance of the yarn. 

Twist selection: When weaving warp yarns, a higher twist is usually required to enhance the wear resistance of the yarn and reduce fraying; for weft yarns or sewing threads, a moderate twist is sufficient. An excessively high twist will make the yarn stiff and make it difficult for knots to loosen when they form. When purchasing, you can inform the supplier of your loom type and fabric structure, and the supplier will recommend an appropriate twist range. 

Twist direction matching: For single yarns, Z-twist or S-twist is usually adopted. When used for plaiting or weaving, it is necessary to pay attention to the twist direction coordination between the warp yarn and the weft yarn - when the twist directions of the warp yarn and the weft yarn are opposite, it can effectively balance the torque during the weaving process and prevent the fabric surface from showing weft skew or knotting and arching. For double-twist yarns used for sewing, the twist direction is usually required to match the rotation direction of the sewing machine to reduce the twisting of the thread loops. 

II. Raw Materials and Number of Combined Strands: Where Lies the Hidden Danger of High Strength Inhomogeneity? 

The performance of double-twisted yarn is not only determined by the twisting process, but also depends on the quality of the raw yarn and the number of combined strands. 

Raw material grade: The ordinary polypropylene filament FDY double-twisted yarn results in ordinary strong double-twisted yarn; the high-strength polypropylene yarn double-twisted yarn results in high-strength polypropylene double-twisted yarn. It is recommended to choose high-strength polypropylene double-twisted yarn for applications such as lifting belts and ropes in heavy-load scenarios; for ordinary luggage straps and clothing accessories, the ordinary specification is sufficient. Guangdong Mengtai High-tech Fiber Co., Ltd. (stock code: 300876) has a relatively complete production and quality control system in the fields of polypropylene double-twisted yarn and high-strength polypropylene double-twisted yarn. 

Number of strands combined: When combining two strands, it is necessary to ensure that the tension and length of the two strands are consistent. Otherwise, after twisting, the "long and short strands" phenomenon will occur, resulting in uneven strength. The double-twist or triple-twist yarns used for sewing threads usually adopt two or three strands combined, and it is required that the surface hairiness is low and the knot strength is high. 

Color and uniformity: When using colored double-twisted yarns, it is necessary to pay attention to the color differences of multiple strands. The colors of different sections of the same bobbin should be consistent, and the color differences between different bobbins should be controllable. It is recommended to ask the supplier to provide sample rolls of recent batches for comparison during the purchase process. 

Summary and Selection Suggestions 

When purchasing polypropylene double-twisting yarn (high-strength polypropylene double-twisting yarn), it is recommended to confirm the following steps: 

Designated purpose: To weave warp yarn, weft yarn, sewing thread or cable rope? Different purposes have different requirements for twist degree, twist direction, number of strands and strength. 

Additional specification: Inform the target denier (total denier), ply count, whether high strength is required, and whether color addition is needed. 

Finally, conduct a sample trial: Use it in a small quantity on your loom or sewing equipment to observe the breakage rate, knotting situation, and the surface effect of the finished product. 

Guangdong Modern High-tech Fiber Co., Ltd specializes in the production and research of polypropylene FDY network yarn, polypropylene network yarn, Polypropylene double-twist yarn, high-strength polypropylene double-twist yarn, and polypropylene ATY yarn. Please feel free to send samples for testing.