Sizing ​Agent for Carbon Fibers"CHEMITYLEN"

Carbon fibers with less fluff and excellent processability are obtained, contributing to the production of high-strength and highly reliable (Carbon Fiber Reinforced Polymer)CFRP. 

Sanyo Chemical's "CHEMITYLEN" Products Binder/Sizing Agent for Carbon Fibers 


Modified carbon fibers by "CHEMITYLEN"

High quality carbon fibers with excellent handling and processability is obtained by using "CHEMITYLEN"

  • It prevents fluffing by imparting properties, facilitates handling, and protects carbon fibers from damage in the processing. 
  • The resulting carbon fiber bundles are flexible, have excellent texture, and high processability (openability* and cuttability). 
  • Improves impregnation of matrix resin. 

     *Fiber opening property: A property that enables thin and uniform spreading of carbon fibers in the fiber opening process, in which carbon fiber bundles are unraveled to spread carbon fibers in order to facilitate impregnation of the matrix resin. 


Modified carbon fibers reinforced plastic (CFRP) by "CHEMITYLEN"

  • Fibers are easily arranged in a homogeneous manner while maintaining fiber length, resulting in CFRP with excellent fiber homogeneity.  The adhesion between carbon fibers and matrix resin is also excellent, resulting in high strength. 
  • The undulations of the yarn can be reduced, and CFRP with excellent surface smoothness can be obtained. 
  • It also has excellent heat resistance.


Various lineups for different applications 

We have a diverse lineup of products for various applications. 

  • "CHEMITYLEN HP, EP" products with excellent impregnability to epoxy resins 
  • "CHEMITYLEN UA" products with excellent flexibility and cuttability.
  • "CHEMITYLEN WS" products with good dispersibility in water and the ability to wash off the sizing agent component from carbon fibers 

"CHEMITYLEN" products are sizing agents that bind carbon fibers together for easier handling. 

"CHEMITYLEN" products, sizing agents, are used in a variety of carbon fiber composite products. 

Carbon fiber composite materials can achieve both high strength and light weight, contributing to energy saving and reduction of environmental impact in various fields. 

Examples of Uses


Pressure vessel

Molded by filament winding using sized carbon fibers. 


Wind turbine components

Molded by pull-torsion using sized carbon fibers. 


Top panel for X-ray diagnostic equipment

Sized carbon fibers are used as prepreg and press molded. 


Aircraft Components

Sized carbon fibers are used as prepreg and autoclave molded. 


Automotive Components

Sized carbon fibers are woven and molded by RTM process (cured after pre-molding)


Laptop chassis 

Sized carbon fibers are pelletized as chop fiber and then injection molded. 

Features of each grade in the "CHEMITYLEN" products 

Products Features Effects
(Polyester/Epoxy type)
Excellent impregnation of epoxy resin.  Wets well with epoxy resin and produces high-strength FRP. 
Excellent fiber-opening properties.  Produces a wide, thin tow. 
Less fluffing.  Fiber length can be maintained and high-strength FRP can be made. 
(Polyurethane type)
Excellent flexibility and cuttability.  Produces flexible, easy-to-handle, easy-to-chop tow. 
Excellent mixing stability with EP and HP series.  The physical properties can be adjusted to your liking by mixing.
 (Polyether type)
Good dispersibility in water. When you do not want to leave the sizing agent component on the surface of carbon fiber, it can be washed off with water. 


Fig. Carbon fiber composite material after epoxy resin impregnation 
SEM photograph of cross section (800x) 

<Features >

  • Excellent epoxy resin impregnation 
  • Excellent bundling and opening properties 
  • Less fluffing 

<General composition>

  • Special polyester 
  • Bisphenol A epoxy resin 
  • Nonionic activator 
  • Water 

Comparison of performance between conventional sizing agents and "CHEMITYLEN EP and HP" products 
Item Conventional sizing agents
(Main component: epoxy resin)
Adhesion amount wt% 1.5 1.5 1.5
Carbon fiber tow basic performance  Fluff amount  mg  2.9 0.7 0.5
Convergence  cm  13.4 18.6 17.1
Openness  mm  6.5 6.7 7.4
Epoxy resins aggregation  s 18.5 6.9 5.7
Emulsion stability  Stability over time


Good Good

"CHEMITYLEN UA" products

Fig. CHEMITYLEN UA products

Moderate flexibility 

Excellent cuttability 
Excellent cuttability due to excellent mixing stability with CHEMITYLEN EP and HP products. 

Bundling and opening properties can be adjusted by mixing with EP and HP products

<General composition >
 Special polyurethane 

Comparison of performance between conventional sizing agent and "CHEMITYLEN UA-40" 
Item Conventional sizing agent
(Main component: epoxy resin)
Adhesion amount wt% 1.5 1.0
Convergence cm 13.4 18.3

Mixing data  of "CHEMITYLEN EP" and "CHEMITYLEN UA" products 

Example of performance adjustment by mixing Chemtylen EP-10/UA-30

Excellent mixing stability with CHEMITYLEN EP and HP products 

 The mixing stability of "CHEMITYLEN EP and HP" products is excellent, so bundling and opening properties can be adjusted by mixing. 

"CHEMITYLEN WS" products

< Features >
  A water-soluble type carbon fiber sizing agent with excellent solubility in water. 

Main composition Polyether aqueous solution  Modified polyether aqueous solution 
Concentration 50 30
Viscosity (25°C, mPa-s)  3000 25000

Comparison of performance between conventional sizing agent and "CHEMITYLEN" WS products
Item Conventional sizing agent
(Main component: epoxy resin)
Adhesion amount wt% 1.5 1.5 1.5
Convergence cm 13.4 13.1 23.8
Openness mm  6.5 6.6 6.4

Main lineup of "CHEMITYLEN" products

"CHEMITYLEN" products performance list

*Temperature at 5% thermal loss during heating of pure resin (in N2, temperature increase at 10°C/min) 
Product Carbon fiber tow performance Heat resitance
convergence tack densitometry fluff Tg ℃ *
CHEMITYLEN HP-10 normal midldle excellent excellent 300
CHEMITYLEN EP-10 good midldle excellent good 310
CHEMITYLEN UA-10 excellent weak normal excellent 270
CHEMITYLEN UA-20 excellent weak good excellent 250
CHEMITYLEN UA-30 good weak good good 270
CHEMITYLEN UA-40 good weak excellent good 230
CHEMITYLEN WS-10 poor strong good N/A 220
CHEMITYLEN WS-20 good midldle good N/A 310

List of properties of "CHEMITYLEN" Products

* Weight % of residual after heat treatment at 130°C for 45 minutes 
Product Liquid type Concentration % * Resin type Ionic species
CHEMITYLEN HP-10 emulsion 40 modified polyester nonion
CHEMITYLEN EP-10 emulsion 40 modified polyester nonion
CHEMITYLEN UA-10 emulsion 39 modified polyurethane anion
CHEMITYLEN UA-20 emulsion 38 modified polyurethane anion
CHEMITYLEN UA-30 emulsion 40 modified polyurethane anion
CHEMITYLEN UA-40 emulsion 35 modified polyurethane anion
CHEMITYLEN WS-10 aqueous solution 50 polyether
CHEMITYLEN WS-20 aqueous solution 50 modified polyether

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