PT7260 & PT7265 Midrange Hardness Flexible Urethane Elastomers

DESCRIPTION

The Shore A-60 and A-65 urethane systems described here are tough elastomeric materials in the middle range hardness for flexible urethanes that have good handling and cured properties. Their slightly tougher nature, compared to softer materials, makes them ideal for applications such as metal forming dies, high strength flexible molds, abrasion resistant shapes and parts, cutting pads, fixtures and flexible parts. Both systems are light colored materials that release air very well and pour easily.
PT7260, the 60-A material, has a lower mixed viscosity and a good blend of cured properties, for durable parts or fixtures. It has a faster setting time for more rapid production of the particular items being cast. With the more rapid gel time, it is especially useful for smaller parts, as it will gel and cure adequately in those smaller masses. Also, for those times when a heat cure is not possible, the PT7260 will cure faster with just a room temperature cure cycle.
PT7265 has a higher mixed viscosity, but it has a longer working time than PT7260, so it will still fill even complicated molds with no problems. The longer working time means that PT7265 can be used to pour larger masses and still have acceptably low shrinkage. PT7265 has 50% more elongation than the PT7260, so it will perform very well in applications where the maximum stretch and elongation is required.
PT7260 and PT7265 are very clear systems, and are low in color, so they can be tinted with either transparent or opaque dyes or pigments to give a variety of colored castings. These two systems can be considered very low hazard potential products, as they do not contain any toxic or regulated raw materials in their makeup. They do not contain methylene dianiline (MDA), or other potentially harmful aniline derivatives, nor do they contain MBOCA or TDI, and they do not contain any hazardous or potentially regulated diluents.


PRODUCT SPECIFICATIONS
 Shore A-60 System
Shore A-65 System

 PT7260 A
PT7260 B
PT7265 A
PT7265 B
ASTM Method 
ColorLight Amber
Light Amber
Light Amber
Light Amber
Visual
Viscosity
1600 cps
30 cps
8000 cps
175 cps
D2392
Specific Gravity, gms./cc
1.041.101.061.01
D1475
Mix Ratio, by Weight
100 : 55
100 : 53
PTM&W
Pot Life, 4 fl oz Mass @ 77°F
20 min.
35 min.
D2471

HANDLING & CURING

Generally, with polyurethane elastomers, full properties are developed in 7 days at room temperature (75°F). 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 to 18 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 to 18 hours at room temperature (70°F to 80°F), then post cure for a minimum of 8 hours at 150°F to 165°F and allow to cool before demolding. 


PACKAGING WEIGHTS

Quart Kit
Gallon Kit
Pail
PT7260 Part A  8 lb.
40 lb.
PT7260 Part B
 4.5 lb.
22 lb.
Kit 12.5 lb.
62 lb.
PT7265 Part A2 lb.
8 lb.
40 lb.
PT7265 Part B1.1 lb.
4.25 lb.
21.5 lb.
Kit3.1 lb.
12.25 lb.
61.5 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
 PT7260 A/B
PT7265 A/BASTM Method
Mix Ratio, by Weight
100 : 55
100 : 53
PTM&W
ColorLight Amber
Light Amber
Visual
Mixed Viscosity, @77°F, centipoise
1350 cps
2900 cps
D2393
Working Time, 4 fl. oz. Mass @ 77°F
20 min.
35 min.
D2471
Cured Hardness, Shore D
60 A±5
65 A±5D2240
Shrinkage, in/in, Mold #1, Vol: .053 Gal.0008.0006D2566
Specific Gravity, grams, cc
1.061.042D1475
Density, lb./cu. in.
.0383.0376D792
Specific Volume,  cu. in./lb.
26.126.5D792
Tensile Strength, psi 
1400 psi
1300 psi
D638
Elongation at Break, %
500 %
750 %
D638
Tear Strength, Die C, pli 195 pli
190 pli
D624
Compression Set, Method B55 %
66 %
D395
Bashore Rebound 60 %
49 %
D2632
Taber Abrasion, H18 Wheel, 1000, grams, 1000 cycles, mg loss 10.2 mg
25 mg
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.