Typically used by sewing thread manufacturers, bonded threads are continuous filaments with high tenacity. A resin coating is applied to single-ply threads to deter any untwisting during the sewing process. Furthermore, these UV-stable threads are two, three, or four-ply materials coated with resin or polyester to keep the threads together during the loop creation. Being slightly stiff, bonded threads can pass through the eye of the needle easily. Apart from that, they are smooth and have a uniform surface that makes the stitch formation consistent. Bonded polyester threads are used in awnings, sailing, boat covers, tarpaulin, travel packs, luggage, and other industries.
Soft Industrial Sewing Thread
Soft multifilament sewing threads are wound to a metered sewing thread spool right after the twisting process. These twisted-only threads may or may not have sewing lubricant applied during the final winding process and are often used as the bottom or bobbin thread because there’s less need for abrasion resistance or ply security. Most of the abrasion in sewing comes from the needle, supplied by the top thread, so bonding of the bottom thread is not as critical. Some advantages are:
- Soft thread is cost-effective for light industrial thread use on low-speed sewing equipment
- Soft thread is low-tech and widely available
- Soft thread can be used as general-purpose twine or string for non-sewing applications
The Advantages of Bonded Thread
Bonded threads are used in a variety of industrial applications. Due to its thick material, bonded threads are used in leather, flat slings, composites, and other compound materials. These threads are widely used in other industrial applications that include heavy tarps, geotextiles, automotive upholstery, and canvas. They are also a great first for heavy stitching applications such as lifting slings, automotive airbags, tie-downs, sports equipment, parachutes, and rock climbing gear. Bonded threads are used in place of soft yarns in various applications including optic cable fibers, binders, zip codes, and more. When coatings are applied on bonded threads, they exhibit resistance to UV exposure along with the prevention of fading or damage from chemicals.
- Bonded thread is slightly stiff and cuts very cleanly, making needle threading easy
- The bonded thread has a smooth, uniform surface for consistency in stitch formation
- Plies are picked up as a group by the hook for good loop formation
- Higher sewing speeds are possible with a protective layer formed by the bond between the thread and the sewing machine contact surfaces
- Additional thread properties like added UV protection and non-wicking can be added in the bonded thread manufacturing step.
In most cases, a bonded poly, bonded nylon, or bonded aramid thread will work for all applications.
Works Cited: Everything You Should Know about Bonded Threads