Sewing thread is an important auxiliary material for making shoes. Sewing thread plays the role of stitching, connecting, setting, and decorating the side and bottom of all kinds of shoes. The compatibility of sewing thread’s physical and chemical properties, product quality, and thread and sewing materials is closely related to the physical quality, appearance, performance, production efficiency, and economic benefits of footwear products.
Although sewing thread is different in terms of usage and material of sewing, most cases, the performance of sewing thread is different. But the sewing line must meet two basic requirements: one is to form a seam, and two is to ensure that all kinds of wearing performance seam. Shoe sewing thread performance of total quality requirements is: there is enough sewing strength and abrasion fastness, service life, reliability and safety of the line should be higher than the upper surface of the material itself, heat resistance and good antistatic performance, reasonable twist and twist knot, can adapt to high-speed sewing, which can be good. From the actual production, the sewing thread should be selected from the following main aspects:
Table of Contents
6 Commonly Used Sewing Threads for Shoes
- Cotton sewing thread: The cotton yarn has the advantages of high strength, low elongation, high heat resistance, stable sewing performance, good antistatic performance, and good general stitching property, but it has large washing shrinkage and poor color fastness. It is not suitable for sewing high-grade products.
- Hemp sewing thread: Including the twine and linen two awns. Footwear mainly used awn twine, awn twine strength, and elongation, with little moisture quickly and wear resistance and high elongation of sesame line is generally about 5%, wet strength can increase 40 ~ 60%. It is mainly used for leather shoes and cloth shoes, such as the stitching and inner line of leather shoes, and the line at the bottom of the seam. The shoe soles, leather shoes, and welt seam.
- Polyester sewing thread: Polyester sewing thread includes two types of polyester staple fiber line (terylene line) and polyester long thread (short polyester long silk thread). The common characteristics of the polyester lines are high strength, small washing shrinkage, elasticity, corrosion resistance, wear resistance, and weather resistance, good thermal stability and dimensional stability, good seams, and beautiful stitching threads.
- Nylon sewing thread: Nylon sewing threads are nylon filament, with high strength, and abrasion resistance, good elasticity, high fatigue resistance, good corrosion resistance, good performance, and strong staining characteristics, and sewing performance is good, but there are great elongation, attached heat resistance, light resistance and resistance to yellowing performance is poor, the type of difference feel have the disadvantage of waxy sense and thermal shrinkage is large, mainly used in shoes, boots, sewing thread, sewing line, help stem money decorative stitching and sewing boots felt in the shovel line, etc.
- Polyester cotton core wire polyester: cotton core wire line is the high strength polyester filament as a core wire, the surface resistance of cotton yarn covered in polyester filament, the wire has high strength, good thermal stability, easy sewing, beautiful stitch, and other advantages, can adapt to the above 4500 RPM high-speed sewing requirements, but the price is high. At present, a small number of leather shoes and leather products are used.
- Polyester cotton blended yarn: At present, the vast majority of the polyester and 35% cotton blended lines are 65%. Polyester cotton blended yarn has many advantages, such as high strength, good dimensional stability, good elasticity, less shrinkage, and strong durability. It is mainly used for the sewing of cloth shoes, and its use is similar to polyester yarn.
How to choose
Optimizing Thread Specifications for Shoe Production
The sewing quality requirements vary for different types of shoes. Therefore, the selection of thread thickness and ply number should be based on the different properties of the sewing materials, such as density, thickness, and weight.
Taking shoe fabrics as an example, the single-thread strength of the sewing thread should exceed that of a single yarn or silk thread in the fabric. Thus, the fineness of the thread should be greater than or similar to that of the yarn or thread in the fabric. Additionally, the thread’s fineness should complement the fabric’s appearance. Furthermore, the selection should consider the specific requirements of different sewing parts, as well as variations in fabric and seam structures.
Understanding Thread Specifications Thread specifications are determined by the tex number and ply number of single yarns or silk threads. For instance, specifications like “14.8 tex x 3” or “16.7 tex x 3 (150Dx3)” for polyester filament threads indicate the thread’s thickness, strength, and application range, with different specifications offering varying strengths.
Impact of Improper Thread Selection Improper selection of thread thickness specifications can directly affect the sewing outcome. For example, when sewing leather shoe uppers, using too thin a thread may result in inadequate seam strength or needle skipping. However, finer sewing threads can produce tightly closed seams that are smooth and less prone to seam puckering, enhancing sewing efficiency.
Shoe Sewing Thread Selection Guide
In general, thicker shoe fabrics or materials require thicker threads, with the top thread slightly thicker than or similar to the bottom thread. Thread selection should consider the performance of the seam in terms of wearability and function, as well as requirements for sewing techniques and appearance quality.
Examples of thread selection include using specific thread types like cotton silk thread for sewing fabric shoe uppers, silk threads like “10×3” or “9×3” for sewing leather shoe uppers, and linen threads like “9.5s/6” or “9.5s/12” for sewing leather shoe soles. Additionally, polyester filament sewing threads are used for sewing leather shoe uppers, while nylon filament sewing threads are used for stitching leather shoe seams or decorative stitching on shoe uppers.
Conclusion
In conclusion, sewing thread is a crucial material in shoe production, playing a vital role in stitching, connecting, and decorating various types of shoes. The selection of the appropriate sewing thread based on material properties and performance requirements is essential for ensuring the quality, appearance, and durability of footwear products.
