PT7290 & PT7295 Hard Flexible Urethane Elastomers

DESCRIPTION

The Shore A-90 and Shore A-95 urethane systems described here are harder flexible elasomers with very tough cured properties that make excellent metal forming tooling and are useful in many other demanding industrial applications. Forming dies, die springs, stripper pads, patterns, gears and tough parts are all applications in which these two elastomers excel.
PT7290 has a low mixed viscosity and a long pot life, so it is very well suited to pouring into closed molds, where it easily fills thin cross sections, and flows through thin pouring spouts readily. It is low in color and accepts dyes or pigments easily when tinted castings are required. 
PT7295 is black in color, has a slightly higher mixed viscosity, and a long pot life. This system is ideal for pouring patterns, dies and pads, where a very tough, slightly flexible material is required. PT7295 will need slightly larger pouring spouts and vents due to its thicker consistency.
PT7290 and PT7295 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 include any hazardous or potentially regulated diluents.


PRODUCT SPECIFICATIONS
 Shore A-90 System
Shore A-95 System

  PT7290 APT7290 BPT7295 APT7295 BASTM Method 
ColorAmber
AmberAmber
BlackVisual
Viscosity
2,500 cps
100 cps7,000 cps
Thin PasteD2392
Specific Gravity, gms./cc
1.031.091.081.11D1475
Mix Ratio, by Weight
100 : 64
100 : 50PTM&W
Pot Life, 4 fl oz Mass @ 77°F
40 – 45 min.
40 – 50 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

Gallon Kit
Pail
PT7290 Part A 8 lb.
40 lb.
PT7290 Part B
5.25 lb. 
26 lb.
Kit13.25 lb.
66 lb.
PT7295 Part A8 lb.40 lb.
PT7295 Part B4 lb.20 lb.
Kit12 lb.60 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
 PT7290 A/B
PT7295 A/BASTM Method
Mix Ratio, by Weight
100 : 64
100 : 50PTM&W
ColorLight Amber
BlackVisual
Mixed Viscosity, @77°F, centipoise
1800 cps
5250 cpsD2393
Working Time, 4 fl. oz. Mass @ 77°F
40 – 45 min.
45 – 50 min.D2471
Cured Hardness, Shore D
90 A±5
95A±5D2240
Shrinkage, in/in, Mold #1, Vol: .053 Gal1.055.0397D792
Specific Gravity, grams, cc
1.0551.10D1475
Density,  lb./cu in
.0381
.0397D792
Specific Volume,  cu. in./lb.
26.325.2D792
Tensile Strength, psi 
3,581 psi
4,000 psiD638
Elongation at Break, %
920 %
225 %D638
Tensile Modulus – 100% Elongation1,086 psi
1,620 psiD412
Tensile Modulus – 200% Elongation
1,393 psi
2,0275 psiD412
Tensile Modulus – 400% Elongation
2,110 psi
2,740 psiD412
Tear Strength, Die C, pli 430 pli
525 pliD624
Compression Set, Method B90 %
43 %D395
Bashore Rebound 42 %48 %D2632
Taber Abrasion, H18 Wheel, 1000, grams, 1000 cycles, mg loss 42 %48 %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.