PT7705 Shore D-75 Rigid Urethane Elastomer
DESCRIPTION
PT7705 is a white, Shore D-75 urethane casting system that is very good for making short run parts and other castings. It has an easy 1 to 1 mix ratio for quick preparation, and a low mixed viscosity for rapid mold filling. PT7705 will fill complicated molds and pick up fine detail with ease. Cured castings made with PT7705 are bright white in color, possess very good tensile strength, and thin section areas have good stiffness. These features make PT7705 ideal for the casting of prototypes to simulate molded parts. It is also an excellent material for preproduction checking of injection molds, as the low viscosity allows easy hand injection into the most detailed cavities. Ease of use an superior properties have made this product very popular for high performance parts and castings.
PRODUCT SPECIFICATIONS
| PT7705 A | PT7705 B | ASTM Method | |
| Color | Clear | Clear | Visual |
| Viscosity | 60 cps | 600 cps | D23932 |
| Specific Gravity, gms./cc | 1.13 | 1.07 | D1475 |
| Mix Ratio, by Weight | 100 : 100 | PTM&W | |
| Pot Life, 4 fl oz Mass @ 77°F | 30 – 40 min. | D2471 |
HANDLING & CURING
PT7705 is an ideal material for applications where a room temperature
cure is desired. This system has a longer pot life to allow the casting
of thicker cross sections when needed. The cured material exhibits a
smooth, dense surface for cosmetic appeal in the finished parts. PT7705
will cure completely at room temperature. Demold time for heavier
section castings is 4 – 6 hours at 77°F. Castings will develop strength
sufficient for most applications in 18 – 24 hours at 77°F, and reach
full cure in 7 days at room temperature. The full cure can be
accelerated by oven curing after the material gels at room temperature.
The time of the cure will depend upon the curing temperature; for
example: at 150°F, the parts should be cured for 2 – 3 hours, however,
at 120°F, the cure time should be 4 – 6 hours. Heat curing will increase
the heat distortion temperature, and therefore improve the heat
stability of the cured material.
PACKAGING WEIGHTS
| Quart Kit | Gallon Kit | Pail | |
| PT7705 A | 2 lb. | 8 lb. | 38 lb. |
| PT7705 B | 2 lb. | 8 lb. | 38 lb. |
| Kit | 4 lb. | 16 lb. | 76 lb. |
Inasmuch
as PTM&W Industries, Inc. has no control over the use to which
others may put material, it does not guarantee that the same results as
those described herein will be obtained. The above data was obtained
under laboratory conditions, and to the best of our knowledge is
accurate. This information is presented in good faith to assist the
user in determining whether our products are suitable for his
application. No warranty or representation, however is intended or
made, nor is protection from any law or patent to be inferred, and all
patent rights are reserved. Before using, user shall determine the
suitability of the product for his intended use, and user assumes all
risk and liability whatsoever in connection therewith. In no event with
PTM&W Industries, Inc. be liable for incidental or consequential
damages. Buyer’s sole and exclusive remedy in such instances shall be
limited to replacement of the purchase price.
TYPICAL MECHANICAL PROPERTIES
| PT7705 A/B | ASTM Method | |
| Mix Ratio, by Weight | 100 : 100 | PTM&W |
| Color | White | Visual |
| Mixed Viscosity, @77°F, centipoise | 300 cps | D2393 |
| Working Time, 4 fl. oz. Mass @ 77°F | 30 – 40 min. | D2471 |
| Cured Hardness, Shore D | 75 A±5 | D2240 |
| Specific Gravity, grams, cc | 1.10 | D1475 |
| Density, lb./cu. in. | .0397 | D792 |
| Specific Volume, cu. in./lb. | 25.2 | D792 |
| Tensile Strength, psi | 5000 psi | D638 |
| Elongation at Break, % | 20 % | D638 |
| Tear Strength, Die C, pli | 750 pli | D624 |
| Compressive Strength, psi | 7000 psi | D395 |
| Bashore Rebound | 62 % | D2632 |
| Heat Distortion Temp: @264 psi @ 66 psi | 125°F 138°F | D1044 |
SAFETY & HANDLING
PTM&W epoxy products are made from raw materials carefully chosen to minimize or even eliminate toxic chemicals, and therefore offer the user high performance products with minimum hazard potential when properly used. Generally, the PTM&W epoxy resins and hardeners will present no handling problems if users exercise care to protect the skin and eyes, and if good ventilation is provided in the work areas. However, all epoxy resins and hardeners can be irritating to the skin, and prolonged contact may result in sensitization; and breathing of mist or vapors may cause allergenic respiratory reactions, especially in highly sensitive individuals. As such, avoid contact with eyes and skin, and avoid breathing vapors. Wear protective rubber apron, clothing, gloves, face shield or other items are required to prevent contact with the skin. In case of skin contact, immediately wash with soap and water, followed by a rinse of the area with vinegar, and then a further wash with soap and water. The vinegar will neutralize the hardener and lessen the chances of long term effects. Use goggles, a face shield, safety glasses or other items as required to prevent contact with the eyes. If material gets into the eyes, immediately flush with water for at least 15 minutes and call a physician. Generally, keep the work area as uncluttered and clean as possible, and clean up any minor spills immediately to prevent accidental skin contact at a later time. Keep tools clean and properly stored. Dispose of trash and empty containers properly. Do not use any of these types of products until Material Safety Data Sheets have been read and understood.