By [email protected] — Charting the depths of expertise
Nonwoven cleanroom Wipers are nonwoven fabrics designed for high-cleanliness requirements. Their performance is determined by: ① raw material type, ② fiber blend ratio, and ③ manufacturing process.
Core Raw Materials for Nonwoven Cleanroom Wipers
Cellulose (Natural & Regenerated) Natural Cellulose: Wood pulp, cotton linter, etc. (primarily wood pulp). Strongly hydrophilic with excellent absorbency, but has low wet strength and is prone to shedding. Regenerated Cellulose (Viscose): Viscose fiber is made from cellulose (wood or cotton pulp), which is processed (alkalized, xanthated, dissolved) into a viscose solution, then wet-spun and solidified into a regenerated cellulose fiber. Its loose fiber structure provides absorbency superior to natural cotton and offers excellent antistatic properties. It is often blended with polyester to balance performance. Synthetic Fiber Polyester (PET): High strength, durable, and good chemical resistance. Can be made into continuous filaments to reduce shedding, but is hydrophobic and has poor absorbency. Polypropylene (PP): Oleophilic (oil-attracting) and hydrophobic (water-repelling). Excellent for oil absorption, low cost, and solvent-resistant, making it ideal for industrial oil wiping. It is also extremely low-linting. It is typically made into a continuous filament structure via a spunbond process and consolidated with thermal point-bonding, which is why its surface has regularly patterned apertures.
Core Raw Material Relationships
Cotton → Cotton Linter → Cotton Pulp → Viscose Solution → Viscose Fiber
Wood → Wood Pulp → Dissolving Pulp → Viscose Solution → Viscose Fiber
I. Plant Materials (Natural Cellulose)
🌾 Cotton
→ Cotton Linter: Solid, short-fiber form = Cellulose + minor impurities
→ Cotton Pulp: Solid sheets = High-purity cellulose extracted from linter
🌳 Wood
→ Wood Pulp: Solid sheets = Cellulose + Hemicellulose + minor Lignin
→ Dissolving Pulp: Solid sheets = High-purity cellulose extracted from wood pulp
II. Chemical Regeneration Process
→ Viscose Solution: The "Cotton Pulp" or "Dissolving Pulp" is processed (alkalized, xanthated, dissolved) to create this solution.
→ Viscose Fiber: The final solid fiber, regenerated by solidifying the viscose solution through a spinneret.
├─ Filament: Viscose Filament / Rayon
└─ Staple Fiber: Viscose Staple Fiber / Artificial Cotton
M-3 Nonwoven Wiper Raw Materials
High-End M-3 (Cotton → Cotton Linter → M-3 Wiper): E.g., Japan's BEMCOT M-3. The raw material is 100% cotton linter. It uses a complex cuprammonium rayon continuous filament process for purification, dissolution, and spinning. The fiber structure is uniform, smooth, highly absorbent, and low-linting.
China M-3 (Wood → Wood Pulp → Dissolving Pulp → Viscose Solution → Viscose Fiber → M-3 Wiper, Cotton pulp is not mainstream for viscose production due to its high cost): E.g., PICOWIPE M-3. The raw material is viscose or a blend with polyester, primarily using the Spunlace process. Performance varies with the viscose/polyester ratio.
A higher viscose content means more softness, higher absorbency, less durability, and better antistatic properties (better moisture absorption = better antistatic), with reduced oil absorption. A higher polyester content means better durability and tensile strength, but reduced softness and liquid absorbency, and increased oil absorption.
0609 Nonwoven Wiper Raw Materials
0609 Nonwoven Wiper (Wood → Wood Pulp → 0609 Wiper): The typical material composition is 55% Wood Pulp + 45% Polyester. Because it skips the chemical regeneration step, its cost is generally lower than M-3 Wiper. The wood pulp provides absorbency, while the polyester provides structural support and wet strength.
Core Raw Material Performance Comparison
| Performance Metric | Wood Pulp (Natural) | Cotton Linter (Natural) | Viscose (from Wood Pulp) | Viscose (from Cotton Linter) | Polyester Staple (Synthetic) | PP Filament (Synthetic) |
|---|---|---|---|---|---|---|
| Liquid Absorbency | Good (fast wicking, limited capacity) | Good (uniform absorption) | Excellent (high capacity) | Excellent + Purer (high retention) | Poor (Hydrophobic) | Very Poor (Non-absorbent) |
| Oil Absorbency | Poor | Poor | Poor | Poor | Medium (absorbs some oil) | Excellent (Oleophilic) |
| Moisture Regain | Medium (approx. 8%) | Medium (approx. 8%) | High (approx. 11-13%) | High + More Stable (approx. 12-14%) | Very Poor (approx. 0.4%) | Very Poor (approx. 0%) |
| Antistatic | Medium | Medium | Good | Good + More Durable (regain aids conductivity) | Poor | Poor |
| Softness | Medium (slightly stiff) | Good (fine, soft fiber) | Excellent (delicate feel) | Excellent + Smooth (like natural cotton) | Stiff | Medium |
| Tensile Strength | Poor (low wet strength) | Poor (low wet strength) | Poor (low wet strength) | Poor (low wet strength) | Good (high dry/wet strength) | Medium (good, but deforms with heat) |
| Abrasion Resistance | Poor | Poor | Poor | Poor | Excellent | Good |
| Shedding Rate | High (staple fiber) | Lower (fibers more uniform) | Medium (depends on spunlace intensity) | Low (uniform structure) | Low (fibers well entangled) | Very Low (continuous filament) |
| Cost Level | Low | Medium | Medium-High | High (20-30% > wood viscose) | Medium | Low |
The Spunlace Process
The manufacturing process for nonwoven cleanroom wipers (e.g., Spunlace, spunbond, cuprammonium rayon) is critical to performance. The Spunlace process, specifically, is used to process staple fibers.
This process works by laying raw materials (wood pulp, cotton linter, viscose staple fiber, or polyester staple fiber) into a web. This web is then struck by countless high-pressure micro-water jets, which force the staple fibers to pierce, displace, and physically entangle to form a fabric.
Consequently, all nonwoven cleanroom wipers made via the Spunlace process are composed of countless staple fibers. This dictates that while they offer good absorbency and a soft feel, their shedding rate is inherently higher than products made from continuous filaments.
Material Selection by Application
High Absorbency (e.g., medical/spills): Choose high-cellulose materials (e.g., 100% viscose). High Cleanliness (e.g., semiconductor/optics): Choose 100% polyester/PP. General Purpose (e.g., electronics/labs): Choose 55% cellulose + 45% synthetic fiber. Oil Absorption: Choose oleophilic materials, primarily polypropylene (PP).
The performance of a nonwoven cleanroom Wiper is a trade-off: cellulose dominates absorbency and antistatic properties (better moisture regain = better antistatic. Note: wood pulp's moisture regain < viscose's), polyester ensures cleanliness and strength, and PP specializes in oil absorption.
