Poly Series RTV Liquid Rubbers
Document Sample
TECHNICAL BULLETIN
Poly 77-Series RTV Liquid Rubbers
High-Performance, High-Elongation, Polyurethane Mold Making Rubbers
DESCRIPTION: Poly 77-Series rubbers consist of a liquid Part
A and Part B, which, after mixing cure at room temperature to FEATURES
economical, flexible mold rubbers. Consider Poly 77-Series rub- • High-performance, high-elongation rubbers
bers for casting plaster, concrete and wax. Resins may also be
cast with proper release agents. Poly 77-Series systems have been • Hardnesses ranging from Shore A50 to A65
formulated to provide excellent abrasion and tear resistance for • Easy-to-use formulations with 1:1 mix ratios
maximum mold life and performance. The high elongation char- • Easy demolding without damaging molds
acteristic of these rubbers enables easy demolding and reduces
• Make tough, long-lasting molds
mold damage when used in high volume casting applications.
MODEL PREPARATION: Porous models such as wood or
plaster must be sealed and then coated with a release agent like bubbles in the plaster and aid release. For casting resins, Pol-Ease®
Pol-Ease® 2300 Release Agent. Lacquer, paint, PVA, Pol-Ease® 2300 is an excellent release agent. For casting concrete, form
2350 Release Agent, PolyCoat and potters soap (plaster only) releases such as Pol-Ease® 2601 or 2650 are preferred. Solvent-
work well as sealers. If shellac is used as the sealer, it must be containing form releases should be avoided since they can cause
thoroughly coated with release agent, because Poly 77-Series rub- mold distortion (i.e., shrinkage or swelling).
bers bond tenaciously to shellac. The sealed or non-porous model After repeated casting with certain resins, plaster and concrete,
should then be coated with Pol-Ease® 2300 Release Agent and molds may shrink slightly since these materials extract oils from
allowed to dry. In every case where there is any question about the rubber. The proper selection of release agent and/or barrier
the compatibility between the rubber and the prepared model sur- coat can minimize this effect.
face, a test cure should be made on an identical surface. Porous Poly 77-Series molds can last many years if stored undistorted on
models must be vented from beneath to prevent trapped air from a flat surface in a cool, dry location out of direct sunlight. UV
forming bubbles in the rubber. resistance of Poly rubbers can be improved by adding Poly UV
MIXING AND CURING: Weigh Part B into a clean metal or Additive. At 0.5% of the total weight of the liquid mix, UV
plastic mixing container. Weigh an equal mass of Part A into the Additive reduces the characteristic surface degradation caused by
same container. Mix thoroughly. Hand mixing with a Poly Paddle sunlight and other UV sources.
is best to avoid mixing air into the rubber. While mixing, scrape CLEAN UP: Tools should be wiped clean before the rubber
the sides and bottom several times to ensure thorough mixing. cures. Denatured ethanol is a good cleaning solvent, but it must be
Pour the rubber as soon after mixing as possible for best flow and handled with extreme caution owing to its flammability and health
air bubble release. hazards. Work surfaces can be waxed or coated with Pol-Ease®
Vacuum degassing helps to provide bubble-free molds, but is usu- 2300 Release Agent so cured rubber can be removed.
ally not necessary.
SAFETY: Before use, read product labels and Material Safety
Allow to cure at room temperature, 77°F. Ultimate properties are Data Sheets. Follow safety precautions and directions. Contact
reached in about seven days, but molds may be used with care with uncured products may cause eye, skin and respiratory irrita-
after curing for 48 hours. Heat accelerates the cure -- low tem- tion, and dermal and/or respiratory sensitization. Avoid contact
peratures slow the cure. Avoid curing in areas where the temper- with skin and eyes. If skin contact occurs, remove with waterless
ature is below 60°F (15°C).
Both Parts A and B react with atmospheric moisture and, there-
fore, should be used up as soon as possible after opening. Before PHYSICAL PROPERTIES
resealing, Poly Purge™, a heavier-than-air, dry gas, can be sprayed 77-50 77-65
into open containers to displace moist air and extend storage life. Mix Ratio, By Weight 1A:1B 1A:1B
For 55-gallon drums of Parts A and B, affix Drierite cartridges on
the small bung during dispensing to protect product from moist Hardness, Shore A 50 65
air entering the drum. Pour Time (min) 15 15
USING THE MOLD: Usually, no release agent is necessary Color Tan Tan
when casting plaster or molten wax in Poly 77-Series molds. For Mixed Viscosity (cP) 1,200 1,600
casting plaster, sponge, dip or spray the mold with Pol-Ease® Specific Volume (in /lb)
3
27.5 27.5
Mold Rinse and then pour plaster on the wet mold to reduce air
55 Hilton Street, Easton, PA 18042 • (800) 858-5990 or (610) 559-8620 • fax (610) 559-8626 • www.polytek.com • sales@polytek.com
PACKAGING
ADDITIVES & ACCESSORIES
Poly 77-50 and Poly 77-65
Mix Ratio: 1A:1B (By Weight) Pol-Ease® 2300 Release Agent
12-oz. can, case of 12 cans
Unit Unit Components
Weight Pol-Ease® 2350 Release Agent
(lb) 1 qt (1.5 lb), 5 gal (26 lb)
Part A Part B Part A Part B
(lb) (lb) (Volume) (Volume) Pol-Ease® 2450 Release Agent
1 qt (2 lb), 5 gal (40 lb)
4.0 2.0 2.0 1 qt 1 qt Pol-Ease® 2500 Release Agent
16.0 8.0 8.0 1 gal 1 gal 12-oz. can, case of 12 cans
80.0 40.0 40.0 5 gal 5 gal Pol-Ease® 2601 Release Agent
900 450 450 55 gal 55 gal 1 qt (2 lb), 5 gal (40 lb), Drum (450 lb)
Pol-Ease® 2650 Release Agent
hand cleaner then soap and water. In case of eye contact, flush 1 qt (1.5 lb), 5 gal (35 lb), Drum (375 lb)
with water for 15 minutes and call physician. Use only with ade- Pol-Ease® Mold Rinse or Mold Dressing
quate ventilation. Poly 77-Series products are not to be used 5 gal (40 lb)
where food or body contact may occur. Poly 77-Series rubbers
burn readily when ignited. Poly PVA Solution (Green or Clear)
1 qt (2 lb), 5 gal (40 lb)
STORAGE LIFE: At least six months in unopened containers Poly Purge™ Aerosol Dry Gas
stored at room temperature (60-90°F). 10-oz can, Case of 12 cans
Poly UV Additive
DISCLAIMER: The information in this bulletin and otherwise
4 oz, 1.0 lb
provided by Polytek is considered accurate. However, no warran-
ty is expressed or implied regarding the accuracy of the data, the PolyCoat
results to be obtained by the use thereof, or that any such use will 1 qt (1.5 lb), 1 gal
not infringe any patent. Before using, the user shall determine the
suitability of the product for the intended use and user assumes all
risk and liability whatsoever in connection therewith.
Dec. 22, 2009 - 77.qxp
55 Hilton Street, Easton, PA 18042 • (800) 858-5990 or (610) 559-8620 • fax (610) 559-8626 • www.polytek.com • sales@polytek.com
