SikaBiresin® UR757

Elastomeric casting resin for mold making

No image available

SikaBiresin® UR757 is a 2-component polyurethane elastomeric casting resin for mold making.  

  • Self-degassing
  • Easy sanding after curing
  • Low moisture sensitivity
  • Good chemical resistance to dedicated release agents for plaster
 
Show all documents
Find this product in your country

Overview

PRODUCT BENEFITS

  • Self-degassing
  • Easy sanding after curing
  • Low moisture sensitivity
  • Good chemical resistance to dedicated release agents for plaster
 

Areas of Application

SikaBiresin® UR757 is designed for production of ceramic case molds by hand casting.
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® UR701 (A)

Canister

5 kg

SikaBiresin® UR757 (B)

Pail

10 kg

 

Product Details

Properties

Component A

SikaBiresin® UR701

Component B

SikaBiresin® UR757

Chemical base

Isocyanate

Polyol

Color

 

mixed

Amber

Blue

Blue

Density

 

cured

1.02 kg/l

1.53 kg/l

1.30 kg/l

Mixing ratio

by weight

50 : 100

Viscosity (CQP029-4)

 

mixed

800 mPa·s

4000 mPa·s

2500 mPa·s

Pot life (CQP021-3 / Gel Timer TECAM)

150 g at 23 °C

25 minutes

Demolding time

16 hours

Curing time

at 23 °C

6 days

Casting thickness

up to 40 mm

Shore A hardness (CQP023-1 / ISO 868)

55 A

Tensile strength (CQP036-6 / ISO 37)

2.75 MPa A

Tear strength (CQP045-1 / ISO 34)

13.5 kN/m A

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

1300 % A

BASHORE resilience (ASTM 2632)

58 % A

Linear shrinkage (CQP014-5)

500 x 40 x 15 mm

1 mm/m A

Glass transition temperature (CQP301-5 / ISO 11357)

-85 °C A

Linear coefficient of thermal expansion (CQP053-1 / ISO 11359)

200 x 10-6 1/K A

Service temperature

-40 – 80 °C

Shelf life

12 months

CQP = Corporate Quality Procedure

A) curing condition: 70 °C for 16 hours

Application

Surface preparation

The material, processing and mold or master-model temperature must be at least 18 °C – 25 °C.
Make sure the mold or master model is clean, dry, dust free 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 starting at the deepest point.
Demolding time may vary depending on casted thickness and room temperature. Sanding is possible 4 hours after demolding.
Do not use for production of plaster molds before 2 days after demolding.
To achieve the highest performance, leave the elastomeric mold at a temperature ≥ 23 °C for 6 days before using it.

STORAGE CONDITIONS

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

Documents