MD-70 REV 1 A/B Page 1 of 2 Date: 05/01/2023
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
www.bjbenterprises.com
SHORE-D SEMI RIGID
By BJB Enterprises. Inc.
An ISO-9001 Certified company
MD-70 REV 1 A/B
70 SHORE D POLYURETHANE ELASTOMER
BJB s MD Series of semi rigid, medium work time urethane elastomers exhibit great flexibility and excellent durability. These
tough, abrasion resistant systems easily process at room temperature. The MD Series is perfect for larger or more complex parts
and offers superior performance in many applications such as rollers, foundry tooling and high impact semi rigid parts. For faster
work times consider BJB s FD Series of elastomers.
RoHS/REACH compliant High tensile and tear strength
Molds and cast parts Cures at room temperature
PHYSICAL PROPERTIES TEST METHOD ELEVATED TEMPERATURE CURE*
Hardness, Shore D ASTM D2240-04e1 70 5
Density (g/cc) ASTM D792-00 1.146
Cubic Inches per Pound N/A 25.11
Color/Appearance Visual Clear Amber
Tensile Strength (psi) ASTM D412-98a(2002)e1 4,900
Tensile Modulus (psi) ASTM D412-98a(2002)e1 1.7 x 10
5
Elongation (%) ASTM D412-98a(2002)e1 320
Tear Strength (pli) ASTM D624-00e1 600
Flexural Strength (psi) ASTM D790-03 2,850
Flexural Modulus (psi) ASTM D790-03 70,000
Shrinkage (in/in) linear ASTM D2566 @ 1 depth 0.005
Izod Impact (ft-lb/in) notched ASTM D256-05 >16.5
Dielectric Constant, 1 MHz ASTM D150-87 3.954
Dissipation Factor, 1 MHz ASTM D150-87 0.0353
*Note: Reported physical properties are based on test specimens cured 1-3 hours at room temperature then 16 hours at 160 F (71 C).
Shrink test specimens are cured for 24 hours at room temperature and then 16 hours at 160 F (71 C).
HANDLING PROPERTIES Part A Part B
Mix Ratio by weight 100 40
Mix Ratio by volume 100 40
Specific Gravity @ 77 F (25 C) 1.105 1.104
Color Pale Yellow Amber
Viscosity (cps) @ 77 F (25 C) Brookfield 3,700 540
Mixed Viscosity (cps) @ 77 F (25 C) Brookfield 2,200
Work Time, 100g mass @ 77 F (25 C) 10 15 minutes
Gel Time 15 20 minutes
Demold Time @ 77 F (25 C) 4 6 hours
Properties above are typical and not for specifications.
MD-70 REV 1 A/B Page 2 of 2 Date: 05/01/2023
For more information call BJB Enterprises, Inc. (714) 734-8450 Fax (714) 734-8929
NON-WARRANTY “Except for a warranty that materials substantially comply with the data presented in Manufacturer’s latest bulletin describing the product (the basis for this substantial
compliance is to be determined by the standard quality control tests generally performed by Manufacturer), all materials are sold “AS IS” and without any warranty express or implied as
to merchantability, fitness for a particular purpose, patent, trademark or copyright infringement, or as to any other matter. In no event shall Manufacturer’s liability for damages exceed
Manufacturer’s sale price of the particular quantity with respect to which damages are claimed.”
NOTE:
Cure times are subject to part size. Smaller parts may need additional time in the mold or add mild heat (100-120 F) to decrease
demold time. Heat will also increase toughness of parts upon demold.
Prolonged direct exposure to sunlight can affect the surface of this product. Cover molds or other products when storing outdoors
CURE SCHEDULE/HEAT CURING:
Most of the physical properties can be achieved in 5-7 days at 77 F (25 C). You may use your own post-cure schedule but the physical
properties may vary from BJB s cure schedule of 1-3 hours at 77 F (25 C) followed by 16 hours at 160 F (71 C). Do not exceed
curing temperature of 200 F (93 C).
PREPARATION AND RELEASING:
When MD-70 REV 1 A/B is used to produce molds or parts from plaster, wood or other porous substrates, we would first recommend
that they be sealed. Release agents may then be applied over the sealed surface.
ACCESSORIES:
BJB offers silicone RTV mold making materials along with a wide range of accessory items. These include de-airing agents, pigments,
mold releases, and Jiffy
Mixers. Visit BJB s website at www.bjbenterprises.com or consult a BJB representative for more
information.
STORAGE:
Store ambient temperatures, 65-80 F (18-27 C). Unopened containers will have a shelf life of 6 months from date of shipment when
properly stored at recommended temperatures. Purge opened containers with dry nitrogen before re-sealing.
PACKAGING Part A Part B Cubic Inches per Kit
Quart Kits 2 lbs. 0.8 lb. 70
Gallon Kits 8 lbs. 3.2 lbs. 281
5-Gallon Kits 40 lbs. 16 lbs. 1,406
55-Gallon Drum Kits 440 lbs. 176 lbs. 15,468
SAFETY PRECAUTIONS:
Use in a well-ventilated area. Avoid contact with skin using protective gloves and protective clothing. Repeated or prolonged contact
on the skin may cause an allergic reaction. Eye protection is extremely important. Always use approved safety glasses or goggles
when handling this product.
IF CONTACT OCCURS:
Skin: Immediately wash with soap and water. Remove contaminated clothing and launder before reuse. It is not recommended
to remove resin from skin with solvents. Solvents only increase contact and dry skin. Seek qualified medical attention
if allergic reactions occur.
Eyes: Immediately flush with water for at least 15 minutes. Call a physician.
Ingestion: If swallowed, call a physician immediately. Remove stomach contents by gastric suction or induce vomiting only as
directed by medical personnel. Never give anything by mouth to an unconscious person.
Refer to the Material Safety Data Sheet before using this product.
WARNING: This product can expose you to chemicals including Toluene diisocyanate, which are known to the State of
California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Handling Guide