PT2846 High Temperature Epoxy Laminating Resin
DESCRIPTION
PT2846
is an amber, unfilled high temperature epoxy laminating resin designed
specifically for demanding high performance composite tooling. PT2846
has good heat resistance, making it capable of providing excellent long
term service in today’s higher temperature curing cycles. The resin has a
medium-low viscosity, and, when combined with the hardeners recommended
here, allows very easy handling in tool fabrication. The mixed systems
wet out the tooling fabrics very readily. This allows faster tool
production than when using more viscous materials. This feature is
achieved without the use of hazardous or potentially restricted
diluents. PT2846 does not contain vinylcyclohexane diepoxide (VCHD).
Three low toxicity hardeners are listed here for use with PT2846. These
hardeners provide a broad range of working times for all sizes of tools
and lay-up methods. All three hardeners give good high temperature
performance with very high physical properties. These hardeners do not
contain methylene dianiline (MDA), or other potentially harmful aniline
derivatives. They are non-staining materials, and will not crystallize
in normal shipping and storage conditions. Other hardeners with special
characteristics are available for use with PT2846. Check with our
Technical Services
department for details and recommendations.
| Hardener | Mix Ratio | Pot Life | Description |
| PT2846 Part B | 100 : 19 | 40 – 45 min. | Intermediate high temperature service hardener with a shorter pot life for smaller tools. Provides a good hard gel at room temperature. Recommended for tools operating in the 275°F to 350°F range. Also, excellent for back-up structure attachment and quick repairs. |
| PT2846 Part B1 | 100 : 22 | 2.5 – 3 hours | Intermediate high temperature service hardener with longer working time than PT2846 Part B, for somewhat larger tools and vacuum bagging operations. PT2846 Part B1 gives a good gel at room temperature (77°F), and can allow an unsupported post cure to a properly gelled tool. It provides durable tools with good dimensional stability, for applications in the 300°F to 350°F range. This combination has a lower mixed viscosity for good fabric wetting. |
| PT2846 Part B2 | 100 : 9.5 | 3 – 4 hours | A unique high temperature service, low toxicity hardener for the most demanding tooling applications. The longer working time allows vacuum bag fabrication of medium sized tools with excellent cured properties. PT2846 Part B2 can be gelled hard at 120°F or higher on a plastic faced plaster pattern for subsequent unsupported post cure and service to over 425°F |
PRODUCT SPECIFICATIONS
| PT2846 A | PT2846 B | PT2846 B1 | PT2846 B2 | ASTM Method | |
| Color | Amber | Amber | Amber | Amber | Visual |
| Viscosity | 7000 cps | 1700 cps | 500 cps | 690 cps | D2392 |
| Specific Gravity, gms./cc | 1.19 | 1.09 | .98 | 1.0 | D1475 |
| Mix Ratio, by Weight | — | 100 : 19 | 100 : 22 | 100 : 9.5 | PTM&W |
| Pot Life, 4 fl oz Mass @ 77°F | — | 40 – 45 min. | 2.5 – 3 hr. | 3 – 4 hr. | D2471 |
SPECIAL INFORMATION
PT2846 Part B and Part B1:
Hardeners PT2846 Part B and Part B1 have been designed to gel hard at
room temperature, to allow removal of the laminate from the pattern
after an overnight (18 to 24 hours) cure at room temperature, and then
be given an unsupported post cure. PT2846 Part B1 has a longer pot life
than PT2846 Part B, to allow vacuum bagging applications on smaller
tools.
PT2846 Part B2: A unique feature of
PT2846 Part B2 is that the heat resistance of the material “leads” the
curing temperature. For example, castings of PT2846 Part B2 and PT2846
cured for 16 hours at 120°F have a heat deflection temperature of over
175°F. With the addition of four hours at 200°F, the heat deflection
temperature of the casting is increased to over 250°F. Values for a
laminate would be much higher due to the reinforcement of the fabric.
This feature allows the fabrication of a high temperature laminate on a
plastic faced pattern, and removal after an initial low temperature
cure. It can then be post cured unsupported with full confidence that
the finished tool will have excellent stability.
TYPICAL MECHANICAL PROPERTIES
| PT2846 A/B | PT2846 A/B1 | PT2846 A/B2 | ASTM Method | |
| Mix Ratio, by Weight | 100 : 19 | 100 : 22 | 100 : 9.5 | PTM&W |
| Mixed Viscosity, @77°F, centipoise | 4000-4500 cps | 3000-3500 cps | 5100-5600 cps | D2393 |
| Pot Life, 4 fl.oz. Mass, @77°F | 40-45 min. | 2.5-3 hr. | 3-4 hr. | D2471 |
| Cured Hardness, Shore D, @77°F, @300°F* | 90, 86 | 92, 87 | 89, 80 (*@350°) | D2240 |
| Specific Gravity, grams, cc | 1.17 | 1.15 | 1.17 | D1475 |
| Density, lb./cu. in. | .0424 | .0417 | .0424 | D792 |
| Specific Volume, cu. in./lb. | 23.6 | 23.9 | 23.6 | D792 |
| Tensile Strength, psi (Laminate)* | 29,440 psi | 30,880 psi | 30,370 psi | D638 |
| Elongation at Break, % (Laminate)* | 1.49 % | 1.57 % | 1.50 % | D638 |
| Tensile Modulus, psi (Laminate)* | 50,303 psi | 54,250 psi | 69,730 psi | D638 |
| Flexural Strength, psi (Laminate)* | 44,463 psi | 47,649 psi | 38,099 psi | D790 |
| Flexural Modulus, psi (Laminate)* | 557,871 psi | 801,525 psi | 540,009 psi | D790 |
| Compressive Strength, psi (Cast Bar) | 15,950 psi | 17,100 psi | 16,880 psi | D695 |
| Compressive Modulus, psi (Cast Bar) | 138,040 psi | 139,540 psi | 138,820 psi | D695 |
| Glass Transistion Temperature, DMA: | 308°F | 338°F | 370°F | D696 |
*Tensile & Flexural Properties Determined with a 1/8” Laminate, Style 7500 Tooling Cloth, Resin Content of 50%-55%
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.