1. Feasibility Analysis of Amino-Modified Silicone Oil for Down Jackets

1. Softness:
   The siloxane main chain of amino-modified silicone oil has extremely low surface tension, which can form a smooth "lubricating layer" on the fiber surface, reducing the friction coefficient between fibers. This makes the down and fabric feel soft and smooth, while avoiding the stiffness or greasiness caused by traditional softeners (such as fatty acid soaps).
2. Antistatic property:
   Amino groups are polar groups that can adsorb moisture in the air through hydrogen bonds, forming conductive paths on the fiber surface to accelerate charge dissipation. This reduces static accumulation (especially suitable for synthetic fabrics like nylon/polyester commonly used in down jackets, which are prone to static generation).
3. Bulkiness:
   The silicone oil film can reduce entanglement and adhesion between fibers, allowing down fibers to maintain a naturally stretched state. At the same time, the rigidity of fabric fibers is reduced and their elasticity is improved, indirectly maintaining the bulky structure of down jackets and reducing the problem of "caking".

2. Key Parameter Recommendations (by Scenario)

1. For Treating Down Fibers (Core Filling)

• Viscosity: Recommended 1000-5000 cps
  Low-viscosity silicone oil has stronger permeability and can evenly wrap fine down fibers (5-20μm in diameter), avoiding fiber adhesion and reduced bulkiness caused by excessively high viscosity. Meanwhile, silicone oil in this viscosity range forms a thin film, which does not increase the weight of down and ensures warmth retention.
• Amine value: Recommended 0.3-0.4 mmol/g
  An excessively high amine value (>0.5) will cause excessive "hardening" of down fibers (due to excessive cross-linking of amino groups), which instead reduces bulkiness. An excessively low amine value (<0.2) results in insufficient polarity, poor antistatic property, and easy detachment of silicone oil. An amine value of 0.3-0.4 mmol/g balances softness, antistatic property, and fiber bonding strength.
• Addition amount: Recommended 1.0-2.0% o.w.f (based on the dry weight of down)
  Below 1%, the functional effect is insufficient; above 2%, it may cause a "greasy feeling" on the down surface, reduce breathability, and even affect the "rebound bulkiness" of down (test index: fill power ≥ 600FP).

2. For Treating Down Jacket Fabrics (e.g., Nylon Taslon, Polyester Pongee)

• Viscosity: Recommended 3000-10000 cps
  Fabric fibers are thicker (20-50μm in diameter), and medium-viscosity silicone oil can form a more stable film on the surface, ensuring longer-lasting softness. Additionally, this viscosity range reduces the problem of "material leakage" during padding/spraying processes (fabrics are mostly dense woven, and low-viscosity oils easily penetrate to the reverse side, causing waste).
• Amine value: Recommended 0.4-0.5 mmol/g
  Fabrics are mainly composed of synthetic fibers (low polarity), so a higher amine value is required to enhance the bonding between silicone oil and fibers (to avoid functional loss after washing). Meanwhile, higher polarity can improve antistatic effects (static problems are more prominent in synthetic fibers).
• Addition amount: Recommended 2.0-3.0% o.w.f (based on the dry weight of fabric)
  Fabrics "absorb more material" than down; 2-3% can form a complete functional film. Excessive addition (>3%) may reduce fabric breathability (affecting the "breathability" of down jackets) or cause a sticky hand feel.

3. Notes

1. Process Adaptation:
   • Down treatment: It is recommended to use the low-temperature dipping method (40-50℃, dip for 30 minutes, then dehydrate and dry). Avoid high temperatures (>80℃) to prevent oxidative yellowing of amino groups.
   • Fabric treatment: It is recommended to use the padding-baking method (pick-up rate 60-70%, bake at 100-120℃ for 3-5 minutes) to ensure cross-linking and curing of silicone oil with fibers.
2. Compounding Optimization:
   To further improve antistatic property, 0.5-1% polyether-modified silicone oil (non-ionic, enhancing hydrophilicity) can be compounded, but compatibility with amino silicone oil should be noted (conduct a small-scale test in advance).
3. Environmental Requirements:
   Choose amino-modified silicone oil with no APEO and low VOC to meet environmental standards for down jacket exports (e.g., OEKO-TEX® 100).

In summary, amino-modified silicone oil is an ideal choice for functional finishing of down jackets. Key parameters should be adjusted according to the "down/fabric treatment" target. Priority is given to viscosity 3000-5000 cps and amine value 0.3-0.4 mmol/g (for down) or viscosity 5000-8000 cps and amine value 0.4-0.5 mmol/g (for fabric), with the addition amount controlled at 1-3% o.w.f.