SilMaterials in Textiles

Silicone in Textile Finishing

Textile finishing — the chemical treatment of woven, knit, or nonwoven fabric to provide softness, water repellency, anti-static performance, or printability — uses silicone formulations across nearly every fabric type. The dominant chemistries:

Amino silicone softeners: micro-emulsions or macro-emulsions of amino-functional silicone (typically aminoethyl-aminopropyl modified PDMS) are the gold-standard fabric softener for cotton and cotton blends. The amino groups attach to negatively-charged cellulose, providing durable softness that survives 20+ home wash cycles. Loadings: 1-5 wt% on fabric weight.

Hydrophobic silane treatments: alkyl silanes (octyl, hexadecyl) and fluorosilanes treat outdoor and performance fabrics for water repellency without compromising breathability. Used in tents, jackets, footwear, and upholstery fabrics.

Anti-static silicone: amino silicone with hydrophilic groups, or quaternary ammonium silanes, dissipate static charge buildup in synthetic fabrics. Important for upholstery, draperies, and clean-room garments.

Silicone-coated printing blankets: HTV silicone rubber blankets used in textile screen-printing, transferring ink from screen to fabric with exceptional release and image quality.

Defoaming during dyeing: dye-bath foaming reduces dye uptake and affects color uniformity. Silicone defoamers (5-30 ppm) are added to control foam during continuous dyeing.

Application Methods

Pad-applied finishes (continuous): fabric passes through a silicone-emulsion bath at 60-80% wet pickup, squeezed by padder rolls, dried at 110-130 °C. The standard method for amino silicone softening.

Spray finishes (selective application): spray nozzles apply silicone selectively to specific fabric zones; used for water-repellent treatments and specialty effects.

Foam-applied finishes (low-add-on): silicone is generated as a foam and applied to one fabric face only, allowing differential treatment of two-sided fabrics.

Stenter cure: post-application drying and curing in a stenter (heated tensile frame) at 130-180 °C for 30-90 seconds. The cure step is critical for durability.

Specifications

Textile-finishing silicone properties characterized by:

• Softness rating: subjective panel evaluation, plus instrumental measurements (Kawabata KES-FB system)
• Wash durability: home laundry wash testing (AATCC 124, EN 25077) for 5, 10, 20, and 50 cycles
• Hydrophilic-hydrophobic balance: water absorption time after silicone treatment; affects sweating behavior in apparel
• Yellowing: amino silicones particularly prone to oxidation yellowing; managed by epoxy or hydroxyl modification
• Surfactant compatibility: emulsion stability with anionic, cationic, and non-ionic surfactants

Sourcing Considerations

Textile silicone is largely commoditized. Chinese producers dominate domestic textile-finishing supply and have substantial export presence. Major brands include:

• Wacker Wetsoft, AMS series amino silicone
• Dow XIAMETER, AMS series amino silicone
• Evonik / Goldschmidt textile auxiliary range
• Many Chinese specialty producers in Shanghai, Zhejiang, Guangdong

For premium technical fabrics (military, automotive interiors, aviation), branded silicones with documented certifications carry cost premium and are often specified.

Related Reading

Silicone oil category, Textile softener silicone, Amino silicone oil, Silicone emulsion category, Water repellency application.