Milk Protein Fiber (Casein)
Nature — What Is Milk Protein Fiber (Casein)?
Milk protein fiber, also known as casein fiber, is a bio-based textile fiber derived from milk casein (casein = protein found in milk). It is produced by extracting the protein and spinning it into fiber form.
Historically developed in the early 20th century, modern versions focus on sustainable production using surplus milk.
Scientific Structure (Explained Clearly)
Casein is dissolved and extruded through spinnerets (spinnerets = small holes that form continuous filaments), then hardened into fibers through chemical treatment.
Core Characteristics
- Protein-based polymer structure
- Smooth filament texture
- Often blended with cotton or viscose
The resulting fiber resembles silk in softness and luster.
Performance — How Milk Protein Fiber Behaves
Softness
Exceptionally smooth hand feel (hand feel = tactile sensation).
Breathability
Allows moisture absorption due to protein structure.
Drape
Provides fluid drape (drape = how fabric falls under gravity).
Reality — What Customers Should Know
Advantages
- Silky texture
- Bio-based origin
- Comfortable against skin
Limitations
- Lower durability than synthetic fibers
- Usually blended for stability
Buying tip: Look for blends combining casein with cotton or regenerated cellulose for improved longevity.