SikaBiresin® UR730

Adjustable elastomeric casting resin for production of flexible molds and parts

SikaBiresin® UR730 is a 2-component polyurethane elastomeric casting resin for production of flexible molds and parts. The Product features an adjustable mixing ratio that allows selection between two distinct hardness levels, enabling optimal adaptation to specific application requirements.  

  • Two hardness level available A30 / A40
  • Low moisture sensitivity
  • Casting thickness up to 150 mm 
  • Low shrinkage after hardening
  • Very high elongation at break
  • Good chemical resistance
 

Overview

PRODUCT BENEFITS

  • Two hardness level available A30 / A40

  • Low moisture sensitivity

  • Casting thickness up to 150 mm 

  • Low shrinkage after hardening

  • Very high elongation at break

  • Good chemical resistance

 

Areas of Application

SikaBiresin® UR730 is designed for production of flexible molds or parts by hand casting or with 2-component low pressure equipment.
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® UR703 (A)

Canister

8 kg A

9.3 kg

SikaBiresin® UR730 (B)

Pail

10.33 kg

17.8 kg A

A Packaging only for full container loads

 

Product Details

Properties

Component A

SikaBiresin® UR703

Component B

SikaBiresin® UR730

Chemical base

Isocyanate

Polyol

Color

 

mixed

Straw yellow

Beige

Beige

Density

 

cured

1.04 kg/l

1.22 kg/l

1.16 kg/l

Mixing ratio

by weight

by weight

40 : 100

45 : 100

Viscosity (CQP029-4)

 

mixed

mixed

3200 mPa·s

1950 mPa·s

2300 mPa·s A

2350 mPa·s B

Pot life (CQP021-3 / Gel Timer TECAM)

160 g at 23 °C

50 minutes

Demolding time

24 hours

Recommended casting thickness

max.

150 mm

Curing time

at 23 °C

5 days

Shore A hardness (CQP023-1 / ISO 868)

30 A, C

40 B, C

Tensile strength (CQP036-6 / ISO 37)

1.5 MPa A, C

2.5 MPa B, C

Tear strength (CQP045-1 / ISO 34)

8.5 kN/m A, C

10 kN/m B, C

Elongation at break (CQP 036-6 / ISO 37)

1500 % A, C

1400 % B, C

Linear shrinkage (CQP014-5)

1000 x 50 x 10 mm

1 mm/m A, B, C

Glass transition temperature (CQP301-5 / ISO 11357)

0 °C A, B, C

Shelf life

12 months

CQP = Corporate Quality Procedure

A) mixing ratio 40 : 100

B) mixing ratio 45 : 100

C) curing condition: 40 °C for 16 hours

Application

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.
To achieve the highest performance, leave the elastomeric mold at a temperature ≥ 23 °C for 5 days before using it.

STORAGE CONDITIONS

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