Research and Development of a Double-Layer Fabric Comprising Natural Cotton Fibers and Bamboo Fibers

　　Raw Material Selection and Fabric Structure Design This product employs combed long-staple cotton combined with a novel eco‑friendly material—bamboo fiber. Designed as a spring/autumn garment fabric, it features a medium‑to‑thick gauge and a plain‑weave double‑layer structure. The warp yarns on both the face and back layers are made of 18.3 tex combed pure cotton; the face-to-back warp ratio is 2:1, with a warp repeat of 24 ends. The weft yarns consist of 27.8 tex×2 bamboo fiber for the face layer and 18.3 tex combed cotton for the back layer, resulting in a face‑to‑back weft ratio of 1:2. A “bottom‑up” interlock method is employed, with an interlock pattern of warp‑weighted plain weave, producing a vertical striped appearance. The face layer exhibits a strong wool‑like texture, while the back layer feels soft and smooth, ensuring comfortable wear. Spinning Process Flow 1. Bamboo Fiber Sliver Production A002D cotton picker → A035B two‑stage mixed opener → A036C opener → A092 feeder → A076 winder → FA212 carding machine 2. Combed Cotton Sliver Production A002D cotton picker → A035B two‑stage mixed opener → A036C opener → A092 feeder → A076 winder → FA212 carding machine → A2.72F pre‑drawing frame → A19lB roving frame → A201E combing machine 3. Blending and Spinning A272F two‑stage drawing frame → A454B roving frame → EJMl28K ring spinning frame → 1332MD winding machine Weaving Process Flow Warp: JCl8.3 tex → CGAl 14 warping machine → Karl Mayer sizing machine → reed threading Weft: JCl8.3 tex, bamboo fiber 27.8 tex×2 Weaving: G6300 rapier loom → inspection and packaging Textile Department Process Configuration and Technical Measures 1. Opening and Cleaning Stage Bamboo fibers exhibit excellent length uniformity and minimal impurities. To prevent excessive mechanical damage that could lead to neps, the process follows the principle of “less draft, more loosening, light drafting, slow speed.” The gap between the beater and dust rods is widened, and the beater speed is appropriately reduced to ensure smooth fiber flow. For long‑staple cotton—fine, long, and low in impurities—the process emphasizes “more loosening, less beating, combined opening and combing, slow feeding, early dropping with minimal breakage,” thereby minimizing fiber damage and breakage. 2. Carding Stage Adhering to the principles of “light drafting, low speed, tight spacing,” this stage focuses on increased combing and reduced dropping to minimize neps. Proper control of the speed ratios among the cylinder, doffer, and apron ensures smooth fiber transfer, enhances fiber separation, reduces neps and impurities in the sliver, and improves the quality of the cotton web. 3. Drawing and Roving Stage Using a two‑stage drawing process, the approach prioritizes “wide gaps, heavy pressure, and low speed,” with rational configuration of front and rear zone drafting. While ensuring that the fine yarn does not develop “hard heads,” the roving twist factor is slightly increased, and rear zone drafting is kept relatively mild to avoid unintended elongation and reduce coarse details. Given bamboo fiber’s tendency to generate static electricity, rubber rollers treated with high‑elastic coatings are employed. 4. Ring Spinning Stage Emphasis is placed on improving the dryness and evenness of the spun yarn, reducing coarse defects and hairiness. Key process parameters such as drafting multiple, nip gap, and roller spacing are carefully optimized. 5. Winding Stage Utilizing the 1332M winding machine equipped with an electronic yarn clearer and an air‑jet splicing device, this stage maintains clean, burr‑free yarn channels to prevent deterioration of yarn quality and the formation of hairiness. Lower winding speeds and reduced winding tension are adopted to minimize strength loss, reduce elongation, and preserve elasticity. The spindle speed reaches 2,200 r/min, with a tension disc set at 3.92 cN. 6. Warping Stage Employing the CGGAll4 high‑speed warping machine, which offers simple operation, superior performance, uniform tension control, and excellent warp beam winding flatness. Operating speed is 500 m/min, with a tension disc set at 4.9 cN. 7. Sizing Stage The process adheres to the principle of “low speed, moderate tension, equal emphasis on penetration and coating.” 1) Sizing formulation: PVA 1799—37.5 kg; modified starch—30 kg; PVA 205—25 kg; QL→89—15 kg; oil agent—3 kg. 2) Sizing procedure: Sizing rate—13%; moisture regain—5%–7%; elongation—1%; sizing solution viscosity—10–12 seconds. Operating speed—30–30 m/min. 8. Weaving Stage Based on the fabric pattern design, the weaving process adopts the principle of “small double‑layer shed, high tension, elevated back beam, early closure.” Adjustments are made to the height ratio between the first and second harness frames, raising them by 2 mm relative to the third through seventh harness frames, allowing for layered warp distribution during loom operation. Simultaneously, higher mounting tension is applied to produce clearer shuttle openings, reduce broken ends, and enhance weaving efficiency. Loom speed is 400 r/min, mounting tension stands at 2,744 N, the front and rear beam heights are set at 1,102 mm, the shedding time is 310 seconds, and rod adjustment ranges from 25 to 95 mm. Harness frame height is maintained at 100–103 mm.