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SikaBiresin® UR303 UR402

Elastomeric casting resin for mold making

SikaBiresin® UR303 UR402 is a 2-component polyurethane elastomeric casting resin for mold making.  

  • Insensitive to moisture
  • Good elasticity
  • Very low shrinkage
  • High elongation at break
  • Rubbery
  • Customized colors with SikaBiresin® Colour Paste
 
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PRODUCT BENEFITS

  • Insensitive to moisture

  • Good elasticity

  • Very low shrinkage

  • High elongation at break

  • Rubbery

  • Customized colors with SikaBiresin® Colour Paste

 

Areas of Application

SikaBiresin® UR303 UR402 is designed for casting of flexible molds for ceramic and gypsum processing. The Product is also well suited for concrete moldings and manufacturing of elastic, flexible parts and components. This product is suitable for experienced professional users only. Tests under actual processing conditions and with additional materials such as coatings and release agents must be performed to proof material compatibility.  

Packaging

   

SikaBiresin® UR303 (A)

Canister

10 kg

SikaBiresin® UR402 (B)

Pail

7 kg

 

Product Details

Typical Product Data
Properties

Component A

SikaBiresin® UR303

Component B

SikaBiresin® UR402

Chemical base

Isocyanate prepolymer

Amine

Color

  

mixed

Colorless-transparent

Colored-transparent

Colored-transparent

Density

 

cured

1.04 kg/l

1.11 kg/l

1.05 kg/l

Mixing ratio

by weight

100 : 35

Viscosity (CQP029-4)

 

mixed

9000 mPa·s

180 mPa·s

4000 mPa·s

Pot life (CQP021-4)

at 23 °C

25 minutes

Demolding time

16 hours

Curing time

at 23 °C

7 days

Shore A hardness (CQP023-1 / ISO 868)

81 A

Tensile strength (CQP036-6 / ISO 527)

10 MPa A

Tear strength (CQP045-1 / ISO 34)

18 N/mm A

Elongation at break (CQP036-6 / ISO 527)

400 % A

Linear shrinkage (CQP014-5)

500 x 40 x 10 mm

0.1 % A

Shelf life

12 months

CQP = Corporate Quality Procedure

A) curing condition: 23 °C for 7 days

Application

Application Information

Surface preparation

The material, processing and mold or master-model temperature shall be between 18 °C – 25 °C.
Make sure the mold or master model is clean, dry, dust and grease free.
If mold or master-model surface is porous, it must be sealed prior applying the release agent.
It is recommended to use wax-based release agents. For further information regarding Sika release agent consult the corresponding Product Data Sheet.

Application

Immediately after mixing pour the Product into the mold starting at the deepest point.
Demolding time may vary depending on casted thickness and room temperature.
If using wood as support core or PUR foam boards with low to middle density, a previous sealing is necessary.
The compatibility of the sealing on PUR foam must be tested separately.

STORAGE CONDITIONS

Both components must be stored at temperature between 15 °C and 25 °C in original unopened containers.