1、YS-4431-L Tubular Twin-Needle Sewing Machine features synchronous feeding by the needle, feed dog, and presser foot, preventing fabric slippage and producing neat, uniform stitches. It utilizes a slide-bar thread take-up mechanism and an imported vertical double-size rotating hook to form two parallel rows of lock stitches. The upper and lower shafts are driven by synchronous toothed belts, while stitch length is adjusted via a knob-type dial and feed direction is controlled by a lever-operated forward/reverse mechanism for user-friendly operation. Additionally, a clutch-type safety device is installed to protect the machine from damage due to overload

2、This model can be optionally equipped with an electronic positioning motor. During sewing pauses, the needle position can be controlled to always stop either above or below the fabric, eliminating the need for frequent handwheel rotation and providing greater operational convenience

This product is widely used in sewing applications such as tents, arch structures, parachutes, hot air balloons, seat cushions, and sofas. It is particularly suitable for filter bags and ring‑shaped cylindrical items