ForMatter/Finishes/coating/Mercerization (cotton lustering)
finish_coating_mercerization

Mercerization (cotton lustering)

coating · polished · mercerized cotton, Mercer process, caustic-soda treatment

Cotton fibers swelled in concentrated sodium hydroxide while held under tension — they swell into a smooth, round, lustrous cross-section that takes dye more uniformly and reflects light like silk. The lustered cotton in fine shirt fabrics, embroidery thread, mass-market socks. John Mercer patented in 1844; Horace Lowe added the tension step in 1890.

Cotton in 18–32% aqueous NaOH at room temperature, held under length tension to prevent shrinkage. Cellulose II crystal-structure transition: fiber swells, surface convolutions disappear, cross-section converts from kidney-shaped to round. Length tension prevents shrink-back; tension-mercerized cotton is ~25% more tensile-strong than untreated, ~10% denser, dye-uptake doubles, luster reads silk-like. Standard pre-treatment for premium cotton (Egyptian, Sea Island, Pima) destined for shirt-weight fabric, embroidery thread, hosiery. The process explains why mercerized cotton thread is more expensive and noticeably shinier than ordinary cotton.

character — silk-like luster, smooth hand, deep dye uptake.

Finish properties

  • levelpolished
  • subcategoryalkaline cotton swelling
  • applies totextile

Second life

reversibilitymoderate — most coatings can be stripped chemically (methylene chloride for paint, NaOH for some powder coats) or thermally / mechanically (sandblasting). Some specialty coatings (DLC, ceramic) require commercial-service strip.
blocks substrate recyclingno
renewabilityfield- to shop-renewable — most paint and clear coats can be touched up or re-coated in service; powder coat and PVD coatings require a coating-house re-application.

SSPC / NACE surface-coating standards; manufacturer technical literature for the specific coating chemistry.

Citations