®TMTrademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow Form No: 751-1 02-2011/kh

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SPECFLEXTM NF 748 Polyol

SPECFLEXTM NE 447 Isocyanate

Description

SPECFLEX NF 748 Polyol and SPECFLEX NE 447 Isocyanate is a 

TDI/MDI based polyurethane flexible system with a final molded 

density of 36-50 kg/m3. The product is designed for short demolding 

time. It is suitable for the production of large and small moldings, 

especially for automotive backrest applications.

Typical Component Properties

Units SPECFLEX NF 

748 Polyol

SPECFLEX 

NE 447 

Isocyanate

Test Method

Viscosity, 25°C Mpa.s 1640-2460 15 ASTM D 445

Specific Gravity, 

25/25°C

- 1.03 1.22 ASTM D 891

Recommended Process Conditions

Polyol needs to be properly mixed before use. Molds must be treated 

with a proper release agent.

Recommended Process Conditions

Units Limits

SPECFLEX NF 748 Polyol pbw 100

SPECFLEX NE 447 

Isocyanate

pbw 40-55

Component Temperature 

(Pol/ISO)

°C 20-25/20-25

Typical Molds 

Temperature

°C 60-65

Demolding Time Min 4-6

Typical Reaction Characteristics1

Units

High 

Pressure 

Machine

Cream Time s 9-11

Rise Time s 90

Free Rise Density 

(Core)

kg/m3

32.3

Handling and Storage

Units (1) SPECFLEX 

NF 748 

Polyol

SPECFLEX 

NE 447 

Isocyanate

Storage Temperature °C 15-25 15-25

Storage Stablility / 

Shelf Life (1)

- 1.03 1.22 ASTM D 

891

1. Stored in the original sealed container in a dry place at the 

recommended temperature protected from direct sunlight

Typical Polymer Properties

These items are provided as general information only.

Units Values Test 

Method 

Index 85 85 95 95 105 105 

Core density Kg/m330.9 36.1 31.1 36.4 31.1 36.2 JIS K 6400 

Tensile 

strength Kg/cm2 1.15 1.52 1.25 1.53 1.29 1.65 JIS K 6400 

Elongation % 115 125 108 110 90 98 JIS K 6400 

Tear Strength kgf/cm 0.6 0.67 0.58 0.77 0.62 0.65 JIS K 6400 

Ball 

Resilience % 63 64 64 65 62 64 JIS K 6400 

Dry set % 5.2 5.1 4.6 4.0 5.2 4.2 JIS K 6400 

Wet set % 13.3 11.2 11.7 9.8 12.2 9.8 JIS K 6400 

25% ILD kgf/314cm2 8.5 12.1 10.5 15.0 13.5 18.8 JIS K 6400 

Typical Polymer Fire Behavior

Numerical flame spread or fire classifications are not intended to reflect 

hazards presented by this or any other material under actual fire conditions.

Typical Polymer Fire Behavior

Standard Typical Values (1)

FMVSS 302 Pass

UNI CT 225 Pass

1. Numerical flame spread or fire classifications are only 

indicative; they are not sales specifications. These are

obtained from tests in Dow laboratories on polymer lab 

specimens.
Safety Considerations: Material Safety Data (MSD) sheets 

are available from The Dow Chemical Company. MSD sheets are 

provided to help customers satisfy their own handling, safety, and 

disposal needs and those that may be required by locally applicable 

health and safety regulations. MSD sheets are updated regularly, 

therefore, please request and review the most current MSD sheet 

before handling or using any product. These are available from the 

nearest Dow sales office.

Customer Notice: Dow encourages its customers to review 

their application of Dow products from the standpoint of human health 

and environmental quality. To help ensure that Dow products are not 

used in ways for which they were not intended or tested, Dow 

personnel will assist customers in dealing with ecological and 

products safety. Your Dow Sales representative can arrange the 

proper contacts.

NOTICE: The information and data contained herein do not constitute sales specifications. The product 

properties may be changed without notice No liability, warranty or guarantee of product performance is created by 

this document. It is the Buyer’s responsibility to determine whether Dow products are appropriate for Buyer’s use 

and to ensure that Buyer’s workplace and disposal practices are in compliance with applicable laws and 

regulations. No freedom from any patent owned by Seller or others is to be inferred.

C o n t a c t I n f o r m a t i o n : F o r m o r e i n f o r m a t i o n a b o u t P U S y s t e m s p r o d u c t s , c a l l T h e D o w C h e m i c a l 

C o m p a n y : h t t p : / / w w w . d o w . c o m / p u s y s t e m s / i n d e x . h t m

www.dow automo ti ve .com

Quality Management System certified by DQS against DIN EN

ISO 9001 – Reg. No. 055759 QM

Dow Automotive Systems | 1250 Harmon Road| Auburn Hills, MI 48326 US Form No. 751-12701 02-2011/kh

Tel.+1 248 391 6300 | Fax +1 248 391 6417 | Email: dowautomotive@dow.com Page 2 of 2 

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