Mulberry raw silk

Mulberry raw silk is internationally graded from 6A (highest) to 2A, A, B, C, and D. For high-end textile manufacturing, buyers should prioritize Grade 6A or 5A, which ensures superior tensile strength, minimal fluff, and high uniformity. Always request a Quality Inspection Certificate from a recognized testing center (like the China National Silk Quality Supervision and Inspection Center) to verify the cleanness, neatness, and elongation properties.

When sourcing, focus on the denier (thickness), commonly ranging from 20/22D to 40/44D. Consistency in denier is critical to prevent breakage during high-speed weaving. Additionally, check the sericin content (usually 20-25%); raw silk must be degummed properly in later stages, so understanding the residual glue rate is essential for calculating the final yield and fabric hand-feel.

To ensure market access, products should meet OEKO-TEX® Standard 100, which guarantees the silk is free from harmful chemicals. For organic claims, verify GOTS (Global Organic Textile Standard) certification. If exporting to the US or EU, ensure compliance with REACH regulations and provide a Phytosanitary Certificate if required by local customs to prove the organic fibers are pest-free.

For warp yarns in luxury garments, high-grade silk with excellent cohesion is required to withstand tension. For weft yarns or filling, a slightly lower grade may be economically feasible. If the silk is intended for medical sutures or cosmetic proteins, it must be sourced from suppliers with ISO 13485 or specific biocompatibility certifications to ensure purity and safety.

Silk is a soft commodity subject to seasonal harvests and climate shifts. To lock in costs, consider long-term framework agreements or staggered purchasing rather than one-time spot buys. Monitor the China Silk Price Index on platforms like Made-in-China.com to time your bulk orders during price troughs.

Never skip pre-shipment inspection (PSI). Since silk is sensitive to moisture, ensure the moisture regain is tested (standard is 11%). Use third-party inspectors to verify the net weight vs. conditioned weight to avoid paying for excess water weight. Ensure the packaging uses moisture-proof liners and robust outer cartons to prevent mold during sea freight.

Utilize Secured Trading Services on Made-in-China.com to ensure payments are only released upon confirmation of receipt and quality. For large-scale industrial orders, use Letter of Credit (L/C) to mitigate financial risks. Always verify the supplier's Business License and Export Qualification to ensure they are a legitimate manufacturer and not an unregulated middleman.

Raw silk is highly hygroscopic and odor-absorbent. It must be shipped in clean, dry containers away from chemicals or strong-smelling cargo. For high-value 6A grade silk, Air Freight is often preferred over Sea Freight to reduce exposure to humidity and transit time, despite the higher cost, as it preserves the luster and fiber integrity.