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Rapid Curing Urethane Castable Rubbers
Product Data Sheet
Product Description and Applications
These are two-component, 100% solid Urethane RTV Elastomers that provide a rubber material with good strength properties.
Their simple 1 to 1 mix ratios, low viscosities and ability to cure in Tin or Platinum Silicone RTVs allow for easy processing.
These flexible Urethane RTVs are used in a variety of applications: prototype rubber parts and molds, or any application where a
flexible rubber part is required.
Unique Characteristics
Curable in Tin or Platinum Silicone RTV
Good Tear Resistance and Elongation
Rapid De-mold Times for Prototyping
Ability to INTER-MIX Systems for Custom Hardness/Durometer
RU-320 A/B RU-350 A/B RU-385 A/B
Color Off White Clear Amber Clear Amber
Mixed Viscosity (cps) 500 530 1,570
Mix Ratio 100 A: 100 B 100 A : 100 B 100 A : 100 B
Shore A Hardness 20 50 85
Tensile Strength (psi) 270 260 1105
Elongation % 800 230 270
Tear Resistance (pli) 60 55 180
Specific Gravity 1.02 1.05 1.05
Gel Time (min) 4-5 4-5 4-5
Demold Time (min) 90-120 60-90 60-90
*Full Cure within Days @ 77F or Post cured at 150F for 12-16 Hours
Preparation of Mold
Use a Silicone RTV Mold Tin or Platinum RTV works best with these systems since no mold release is needed when casting
into Silicone RTV. If using Latex, Urethane RTV rubber or any other type of mold, a proper mold release must be used MR150
or ER-2300 is recommended. Ensure that all surfaces are dry and free from moisture prior to casting to prevent material
contamination.
Mixing
Before mixing, ensure that material and molds are at proper working temperature above 65F. These systems are fast curing
and should be processed quickly. Before adding A to B, part B should be stirred or shaken thoroughly to ensure that any
separated material is remixed. Select a clean, dry plastic container for mixing. Avoid using wood or paper products, which could
cause cure problems. Weigh out the proper ratio of A to B and mix well, scraping sides and bottom of mixing container to ensure
a thorough mix. After mixing usually within 45-60 seconds immediately pour into mold.
Curing
Do not disturb the mold until part is ready to be de-molded. Prematurely demolding parts may cause deformation, especially in
thin areas. Preheating molds 100F will expedite cure, while low temperatures will slow curing time and extend the demold
time. To expedite a full cure, post cure parts at 150F for 12-16 hours. Note: Pressure casting applying positive pressure 40-60
psi will improve clarity and rubber performance.
1
2
Storage/Shelf Life
A and B components must be stored in their original, unopened containers at temperatures between 65F and 85F. Shelf life of
materials when kept in unopened sealed containers, at the recommended storage conditions, is 6 months. Containers should
not be opened until ready for use. Once containers are opened, material should be used in a short time period. Pre-test any
aged material before using.
Handling and Safety
Use proper equipment gloves, glasses and apron when using materials. Avoid direct contact with skin and eyes. If skin contact
occurs, clean area with waterless hand cleaner or isopropyl alcohol. For eye contact, flush eye with water for 15 minutes and
call physician. Use materials under adequate ventilation. *See SDS for further information.
ACCESSORIES
Colorants:
All pigments should be added to the “B” side only at 1-2%. Castable urethanes are affected by direct and indirect sunshine and
will discolor over time.
CU Pigment Red, Yellow, White, Blue, Black, Brown, Fleshtone
Bright Shade Powder Green, Orange, Red, Yellow, Pink Dry powdered pigments requiring thorough premixing
UD Dye Red, Yellow, Black, Blue Transparent coloring used in Clear and Transparent Urethane & Epoxy
THE INFORMATION AND DATA CONTAINED HEREIN ARE BASED ON INFORMATION WE BELIEVE RELIABLE. EACH USER OF THE
MATERIAL SHOULD THOROUGHLY TEST ANY APPLICATION AND INDEPENDENTLY CONCLUDE SATISFACTORY PERFORMANCE
BEFORE COMMERCIALIZING. SUGGESTIONS OF USES SHOULD NOT BE TAKEN AS INDUCEMENTS TO INFRINGE ON ANY
PARTICULAR PATENT.