The production process of nylon 66 (also called polyamide 6.6) and polyester sewing thread can be divided into two main categories: continuous filament fibers and staple fibers. Here's the detailed workflow:

‌Continuous Filament Nylon 66 and Polyester Sewing Thread

1. Spinning & Shaping: Chips are melted, extruded and wound through spinnerets to form continuous multi-filaments^[1] yarns with specific filament counts (denoted as "F").

2. Twisting & Plying‌: The multi-filaments yarns undergo primary twisting (always S direction)^[2] and secondary twisting (always Z direction)^[3] on twisters to form raw white plied yarns.

3. Dyeing & Finishing‌: The raw white plied and twisted yarns are dyed and treated with dyeing assistant in to different colors in dye house, finally wound and lubricated on spools.

Staple Fiber Sewing Thread (Spun Sewing Thread)

1. Fiber Preparation‌: Chips are melted and extruded into cotton-like staple fibers.

2. Spinning Process‌:

Carding & Lap Formation: Fibers are carded and formed into coarse yarns.

Drafting: Coarse yarns are further drawn into fine yarns.

3. Twisting & Plying‌: Fine yarns are twisted and plied to form raw white plied yarns.

4. Dyeing & Finishing‌: The raw white plied and twisted yarns are dyed and treated with dyeing assistant in to different colors in dye house, finally wound and lubricated on spools.

Core Spun Sewing Thread

Blended filament and spun fibers to twist, will experience similar twisting and dyeing processes.

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It forms sewing threads by material types:‌

* Filament Threads: Polyester high tenacity sewing thread, nylon 66 high tenacity sewing thread, bonded polyester thread, bonded nylon 66 thread, trilobal polyester embroidery thread.

* Staple Threads: Cotton sewing thread, spun polyester sewing thread.

* Blended Threads: Poly poly core spun sewing thread, cotton poly core spun sewing thread.

Proper selection of thread material and specifications based on sewing requirements ensures optimal stitching performance‌.

 Production of Sewing Thread   Dyeing of Bonded Nylon 66 Sewing Thread   Filament Sewing Thread Twisting

 Bonded Nylon 6.6 Sewing Thread    Polyester Sewing Thread    Core-spun Sewing Thread

[1]. Multifilament yarn - ScienceDirect

[2], [3]. How Twist and Twist Directions Influences the Sewing Thread Spinability - Science Alert