Views: 0 Author: Site Editor Publish Time: 2026-06-04 Origin: Site
In the textile printing and dyeing industry, the color richness and visual depth of black and dark fabrics (such as navy blue, coffee, and dark green) are core indicators of product quality. However, irregular light scattering from fiber surfaces, residues from pre-treatment, or uneven dye distribution often cause dark fabrics to appear "whitish," "frosted," or "dull grey," seriously affecting the quality of finished garments.
Zhejiang Kefeng Silicone Co., Ltd. , established in 2002 with a registered capital of 60 million RMB and three manufacturing bases, is a leading professional manufacturer of block silicone oil in China. Leveraging strong R&D capabilities and large-scale production (monthly production capacity of crude block silicone oil has reached 1,000 tons), Kefeng Silicone has launched its Deepening Block Silicone Oil specifically designed for dark fabrics. This product does not physically deepen color by increasing dye absorption. Instead, it utilizes optical modification principles to form an ultra-thin, transparent film with a specific refractive index on the fiber surface. This film effectively reduces diffuse reflection and enhances the absorption of specific wavelengths of light (especially the black/dark spectrum), thereby visually increasing the color depth of black polyester fabrics by 50-80% . It achieves a breakthrough "deepening without additional dyeing" effect.
Optical Modification Technology: After film formation, the refractive index (RI) of Kefeng's Deepening Block Silicone Oil is precisely engineered to be between that of air and the fiber. Verified by third-party and extensive customer tests, when applied to black polyester fabric, the color depth (K/S value) increases by 50-80% . The L value (lightness) significantly decreases, and the visual blackness becomes purer, deeper, and free of greyish haze.
Eliminates "White Frost" and "Shading": Effectively covers micro-fine white marks and shading on the surface of polyester, nylon, and their blended fabrics caused by friction, loose color, or uneven weaving. The dark fabric presents a uniform, rich, deep black appearance.
Widely Applicable to Dark Colors: Particularly outstanding for deepening synthetic fiber dark colors such as black, navy blue, charcoal grey, and dark brown.
Kefeng employs a ternary copolymer block structure design, allowing this product to provide fabrics with an excellent soft, full, and smooth hand feel while achieving significant deepening. The silicone main chain forms a directionally aligned flexible film on the fiber surface, greatly reducing the coefficient of friction between fibers, ensuring a silk-like touch and excellent drape – avoiding the stiffness or tackiness that traditional deepening agents may cause.
High Stability: The product exhibits excellent alkali resistance, hard water resistance, and electrolyte resistance. It is not prone to demulsification or oil spotting in dyeing machines or stenter padder troughs, ensuring stable continuous production.
Good Compatibility: Can be used in the same bath with anionic, nonionic softeners, antistatic agents, etc., facilitating process integration.
Low Yellowing: Even under high-temperature setting (180°C), it causes almost no yellowing of the fabric, ensuring the pure shade of dark fabrics.
After setting and crosslinking, the silicone oil film firmly bonds with the fibers, giving the product excellent resistance to washing and dry cleaning. The deepening effect and hand feel maintain a high level after multiple washes. The product meets APEO-free and environmental protection requirements, complying with textile ecological standards.
Dye Savings: Since the deepening effect comes from physical optical modification, it can save 10-20% of dye consumption, reducing wastewater load.
Repairing Off-Grade Fabric: Effectively masks "light shade off-grade fabric" caused by insufficient dyeing depth, bringing its visual depth up to standard and avoiding downgrade losses.
The core principle of Deepening Block Silicone Oil is based on refractive index matching and anti-reflective film theory. The surface of untreated polyester fiber is rough, causing strong diffuse reflection of light and making the color appear "dull grey." Kefeng's Deepening Silicone Oil spreads on the fiber surface to form a continuous transparent film with a refractive index of approximately 1.43-1.45 (polyester RI ~1.58, air RI 1.0). This film acts as a "light trap":
Reduces the sudden change in refractive index at the air-fiber interface, lowering reflected light intensity.
Allows more light to enter the fiber interior and be absorbed by the dark dye molecules, rather than being reflected.
Diffuse reflection is weakened, while specular reflection components relatively increase. As a result, the color perceived by the human eye becomes darker and richer, achieving a 50-80% depth increase.
Synthetic Fibers: Polyester, nylon, polyamide, and their blends (T/C, T/R).
Natural Fibers: Dark shades of cotton, linen, viscose, and mercerized cotton (effect is slightly less than on synthetics but still significant).
Others: Surface deepening treatment for artificial leather and microfiber leather.
Dosage: 10 – 40 g/L (adjust according to fabric type, original depth, and required deepening degree; for black polyester, can be 30 g/L or higher)
pH Value: 5.0 – 6.5 (weakly acidic)
Wet Pick-up: 65% – 80%
Curing Temperature & Time: 160°C – 180°C × 60 – 90 seconds
Important Notes:
Stir or dilute thoroughly before use to ensure a uniform working bath.
Avoid direct high-speed mixing with strongly anionic or strongly cationic auxiliaries to prevent demulsification.
Store in a cool, dry, well-ventilated place, avoiding exposure to sunlight or freezing.
Pre-trial Recommended: Always conduct a laboratory trial before bulk production to determine the optimal dosage and process conditions, especially for different fiber types and depth requirements.
Parameter | Typical Range | Remarks |
|---|---|---|
Appearance | Transparent to slightly milky white liquid | Or translucent emulsion |
Ionicity | Weakly cationic / Nonionic | Depends on specific grade |
Solid Content | 30% ± 2% | High concentrate available |
pH Value (Neat) | 5.0 – 7.0 | Weakly acidic to neutral |
Viscosity (25°C) | 500 – 3000 mPa·s | Designed according to molecular weight |
Solubility | Easily dispersible in water | Disperses with stirring at room temperature |
Recommended Dosage | 10 – 50 g/L (conventional) | Use 30-40 g/L for black polyester deepening |
As a national high-tech enterprise established in 2002, with a registered capital of 60 million RMB and three manufacturing bases, Zhejiang Kefeng Silicone Co., Ltd. is one of the "Top 20 Enterprises in China for Comprehensive Strength in Textile Printing and Dyeing Auxiliaries." The company's monthly production capacity of crude block silicone oil has reached 1,000 tons, ensuring product quality stability and timely supply. Its series of hydrophilic silicone oils, deepening resins, and deepening silicone oils developed for various fibers have become the preferred choice for many auxiliary manufacturers and printing and dyeing mills.
The Deepening Block Silicone Oil (Enhancing Color Depth of Black/Dark Fabrics) from Zhejiang Kefeng Silicone Co., Ltd. represents cutting-edge technology combining "physical optical finishing" with "hand feel improvement." It breaks through the limitations of traditional dye-dependent deep coloring, achieving a remarkable 50-80% visual deepening effect at lower cost and in a more environmentally friendly way, while imparting an excellent soft, smooth hand feel to the fabric.
For textile printing and dyeing enterprises, choosing Kefeng's Deepening Block Silicone Oil is not just choosing an efficient deepening auxiliary – it is choosing a reliable partner backed by technology-driven, large-scale production, and stable quality. For detailed technical manuals for specific grades, samples, or customized application solutions, please contact the Zhejiang Kefeng Silicone sales team.
