PT7667 A/B Shore D-65 Urethane Casting System
DESCRIPTION
PT7667
A/B is a tough, hard elastomeric material that has superior toughness
and abrasion resistance, for good performance in demanding industrial
applications. It has a good low mixed viscosity for easy processing, and
it will duplicate fine detail pattern surfaces quite well. PT7667 has
low initial cured shrinkage, and remains stable throughout its service
life.
PT7667 will make extremely durable patterns, dies, fixtures and molds.
It has very good tensile strength and high elongation properties, for
good long-term toughness. Its excellent abrasion resistance makes it
ideal for use in foundry patterns. Being slightly harder than usual
candidates for this application, there is less tendency for sand to
stick to such patterns.
PT7667 can be considered a very low hazard potential product, as it does
not contain any toxic or regulated raw materials in its makeup. IT does
not contain methylene dianiline (MDA), or other potentially harmful
aniline derivatives, nor does it contain MBOCA or TDI, and does not
include any hazardous or potentially regulated diluents.
PRODUCT SPECIFICATIONS
| PT7667 A | PT7667 B | ASTM Method | |
| Color | Light Amber | Amber** | Visual |
| Viscosity | 4000 cps | 180 cps | D23932 |
| Specific Gravity, gms./cc | 1.08 | 1.09 | D1475 |
| Mix Ratio, by Weight | 100 : 50 | PTM&W | |
| Pot Life, 4 fl oz Mass @ 77°F | 20 – 25 min. | D2471 |
** A Black and Red version of PT7667 Part B are available by Special Order.
HANDLING & CURING
Generally, with polyurethane elasomers, full properties are developed in
7 days at room temperature (75°F). The nature of this system is to cure
somewhat faster, however, so the castings reach full properties sooner
than the 7 days. Almost 90% of full hardness is reached in a few hours,
and the ultimate cured hardness is achieved in 24-36 hours. This faster
“though cure” allows faster tool production rates, and therefore more
efficient production. Temperatures below 75°F will lengthen the cure
time, and if the ambient temperature is below 60°F, additional heat may
be necessary for proper cure. Elevated temperatures will accelerate the
cure of urethanes, but care must be taken if a higher temperature is
used to cure the material. Generally, the higher the curing temperature,
the greater the final cured shrinkage. When heat curing for more rapid
processing, to best control shrinkage, the casting should be allowed to
set for 12 hours at room temperature before an oven post cure. A typical
accelerated curing cycle, therefore, would be: Allow to gel on the
pattern for 12 hours at room temperature (70°F-80°F), then post cure for
a minimum of 4 hours at 150°F to 165°F and allow to cool before
demolding.
PACKAGING WEIGHTS
| Gallon Kit | Pail | Drum Kit | |
| PT7667 Part A | 8 lb. | 40 lb. | 460 lb. |
| PT7667 Part B | 4 lb. | 20 lb. | 230 lb. |
| Kit | 12 lb. | 60 lb. | 690 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
| PT7667 A/B | ASTM Method | |
| Mix Ratio, by Weight | 100 : 50 | PTM&W |
| Color | Amber, Red or Black** | Visual |
| Mixed Viscosity, @77°F, centipoise | 2700 cps | D2393 |
| Working Time, 4 fl. oz. Mass @ 77°F | 20-25 min. | D2471 |
| Cured Hardness, Shore D | 65 D | D2240 |
| Shrinkage, in/in, Mold #1, Vol: .053 Gal | .001 in/in | D2566 |
| Specific Gravity, grams, cc | 1.08 | D1475 |
| Density, lb./cu in | .0390 | D792 |
| Specific Volume, cu. in./lb. | 25.6 | D792 |
| Tensile Strength, psi | 6,558 psi | D638 |
| Elongation at Break, % | 633 % | D638 |
| Tensile Modulus @ 100% Elongation | 2055 psi | D412 |
| Tensile Modulus @ 200% Elongation | 2551 psi | D412 |
| Tensile Modulus @ 400% Elongation | 4184 psi | D412 |
| Tear Strength, Die C, pli | 654 pli
| D624 |
| Compression Set, Method B | 85 % | D395 |
| Bashore Rebound | 52 % | D2632 |
| Taber Abrasion, H18 Wheel, 1000 grams load, 1000 cycles, mg loss | 37 mg | D1044 |
** A Black and A Red Version of PT7667 Part B are available by Special Order. Amber is the standard color.
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.