The Complete Technical Guide for Hygiene Product Manufacturers

ES fiber has quietly become the backbone of the global hygiene products industry. If you manufacture diapers, sanitary napkins, incontinence products, or medical wipes, you’ve almost certainly used ES fiber — even if you didn’t realize it.

This guide explains everything you need to know about ES fiber (polyethylene/polyester bicomponent) for hygiene applications: what it is, how it’s made, key specifications, sourcing strategies, and how to evaluate suppliers.

What Is ES Fiber?

ES fiber (short for “Ethylene Sheath”) is a bicomponent synthetic fiber consisting of two different polymers in a sheath-core configuration:

• Sheath: Polyethylene (PE) — low melting point (approximately 130°C)
• Core: Polyester (PET) — high melting point (approximately 260°C)

This unique structure gives ES fiber its defining characteristic: thermal bondability at low temperatures.

When heated to 130–150°C, the polyethylene sheath softens and fuses, binding fibers together while the polyester core maintains structural integrity. This enables non-woven fabric production without chemical binders — a critical advantage for hygiene products that contact skin.

Why ES Fiber Dominates Hygiene Products

1. Thermal Bonding Without Adhesives

Traditional non-wovens require chemical binders (latex, acrylics) to hold fibers together. ES fiber eliminates this need:

• No chemical residues — critical for skin-contact products
• Softer hand feel — no stiff binder spots
• Lower production cost — no binder application step

2. Superor Softness

ES fiber non-wovens achieve 10–30% softer hand feel compared to chemically bonded alternatives. This is why premium diaper top sheets and sanitary napkin covers use ES fiber exclusively.

3. Excellent Liquid Management

ES fiber can be engineered with:

• Hydrophilic treatment — wicks liquid away from skin
• Hydrophobic treatment — keeps surface dry
• Bilayer structures — hydrophilic core, hydrophobic surface

4. Thermal Stability in Use

Although the sheath melts at 130°C during production, the finished non-woven is stable at use temperatures (up to 60°C). The polyester core provides dimensional stability.

Manufacturing Process: How ES Fiber Is Made

Step 1: Bicomponent Spinning

Two polymers are co-extruded through a single spinneret with sheath-core distribution:

• Polyethylene (sheath) fed through outer annular channel
• Polyester (core) fed through central capillary
• Precise temperature control prevents mixing at the interface

Step 2: Quenching and Drawing

Extruded filaments pass through a quenching chamber (cooled air) then undergo hot drawing to orient polymer molecules and develop tenacity.

Step 3: Crimping (Optional)

For hygiene applications requiring bulk and loft, fibers may be mechanically crimped (3D spiral crimp) to improve non-woven porosity.

Step 4: Cutting

Continuous tow is cut to specified staple length (typically 32mm to 64mm for hygiene applications).

Step 5: Surface Treatment (Critical for Hygiene)

ES fiber for hygiene products requires surface treatment to achieve desired liquid management:

Key Specifications for Hygiene-Grade ES Fiber

Table 1: Technical Specifications Guide

Applications in Hygiene Products

ES fiber is used in virtually every modern hygiene product. Here’s the breakdown:

Table 2: ES Fiber Applications in Hygiene

Hygiene Product	ES Fiber Role	Recommended Spec	Key Requirement
Baby Diapers	Top sheet (hydrophobic), acquisition layer (hydrophilic)	2D to 4D x 38mm	Softness, rapid wicking
Blog Details Home Blog ES Fiber (Polyethylene/Polyester Bicomponent) for Hygiene Products: Specifications and Sourcing ES Fiber (Polyethylene/Polyester Bicomponent) for Hygiene Products: Specifications and Sourcing 2026-06-02 The Complete Technical Guide for Hygiene Product Manufacturers ES fiber has quietly become the backbone of the global hygiene products industry. If you manufacture diapers, sanitary napkins, incontinence products, or medical wipes, you’ve almost certainly used ES fiber — even if you didn’t realize it. This guide explains everything you need to know about ES fiber (polyethylene/polyester bicomponent) for hygiene applications: what it is, how it’s made, key specifications, sourcing strategies, and how to evaluate suppliers. What Is ES Fiber? ES fiber (short for “Ethylene Sheath”) is a bicomponent synthetic fiber consisting of two different polymers in a sheath-core configuration: Sheath: Polyethylene (PE) — low melting point (approximately 130°C) Core: Polyester (PET) — high melting point (approximately 260°C) This unique structure gives ES fiber its defining characteristic: thermal bondability at low temperatures. When heated to 130–150°C, the polyethylene sheath softens and fuses, binding fibers together while the polyester core maintains structural integrity. This enables non-woven fabric production without chemical binders — a critical advantage for hygiene products that contact skin. Why ES Fiber Dominates Hygiene Products 1. Thermal Bonding Without Adhesives Traditional non-wovens require chemical binders (latex, acrylics) to hold fibers together. ES fiber eliminates this need: No chemical residues — critical for skin-contact products Softer hand feel — no stiff binder spots Lower production cost — no binder application step 2. Superor Softness ES fiber non-wovens achieve 10–30% softer hand feel compared to chemically bonded alternatives. This is why premium diaper top sheets and sanitary napkin covers use ES fiber exclusively. 3. Excellent Liquid Management ES fiber can be engineered with: Hydrophilic treatment — wicks liquid away from skin Hydrophobic treatment — keeps surface dry Bilayer structures — hydrophilic core, hydrophobic surface 4. Thermal Stability in Use Although the sheath melts at 130°C during production, the finished non-woven is stable at use temperatures (up to 60°C). The polyester core provides dimensional stability. Manufacturing Process: How ES Fiber Is Made Step 1: Bicomponent Spinning Two polymers are co-extruded through a single spinneret with sheath-core distribution: Polyethylene (sheath) fed through outer annular channel Polyester (core) fed through central capillary Precise temperature control prevents mixing at the interface Step 2: Quenching and Drawing Extruded filaments pass through a quenching chamber (cooled air) then undergo hot drawing to orient polymer molecules and develop tenacity. Step 3: Crimping (Optional) For hygiene applications requiring bulk and loft, fibers may be mechanically crimped (3D spiral crimp) to improve non-woven porosity. Step 4: Cutting Continuous tow is cut to specified staple length (typically 32mm to 64mm for hygiene applications). Step 5: Surface Treatment (Critical for Hygiene) ES fiber for hygiene products requires surface treatment to achieve desired liquid management: Treatment Purpose Application Hydrophilic finish Wicking, rapid liquid uptake Diaper absorbent core Hydrophobic finish Repels liquid, keeps surface dry Diaper top sheet Silicone finish Soft hand feel, anti-clumping Sanitary napkin covers Anti-bacterial finish Inhibits bacterial growth Medical wipes, incontinence Key Specifications for Hygiene-Grade ES Fiber Table 1: Technical Specifications Guide Specification Typical Range for Hygiene Why It Matters Denier per Filament 1.5D to 6D Finer = softer hand feel Cut Length 32mm to 64mm Matches carding/pinning equipment Sheath Melting Point 130°C to 150°C Lower = energy savings in bonding Core Melting Point 260°C (PET) Provides structural integrity Tenacity ≥ 3.5 cN/dtex Withstands processing and use Elongation at Break 30% to 80% Affects non-woven tensile strength Crimp 8 to 14 crimps/25mm Higher = better loft and porosity Finish Type Hydrophilic / hydrophobic / silicone Determines liquid management Finish Pickup 0.2% to 0.5% Too low = poor processability; too high = blocking Applications in Hygiene Products ES fiber is used in virtually every modern hygiene product. Here’s the breakdown: Table 2: ES Fiber Applications in Hygiene Hygiene Product ES Fiber Role Recommended Spec Key Requirement Baby Diapers Top sheet (hydrophobic), acquisition layer (hydrophilic) 2D to 4D x 38mm Softness, rapid wicking Contact Us Guangzhou Octopus Fiber Co.,Ltd. E-mail heidi@bzyfiber.com Quick Contact About Us Products Blogs Application Contact Us Our Address Address Room 1510-1511, North Tower, Xijiao Commercial and Trade Center, No. 165 Qiaozhong Middle Road, Liwan District, Guangzhou City, Guangdong Province， China. Tel 86-18102756185 0086-18102756185 Privacy Policy |  Sitemap China Good Quality Polyester Staple Fiber Supplier. Copyright © -2026 Guangzhou Octopus Fiber Co.,Ltd. . All Rights Reserved. 0086-18102756185