PT4925 Aluminum Filled High Temperature Epoxy Casting Resin
is an aluminum filled high temperature epoxy resin for use in making
cast tools and parts requiring heat resistance and good thermal
conductivity. PT4925 has a high aluminum content which insures these
properties and allows easy machining of the finished castings. It
handles easily, filling mold cavities well, and it reproduces fine
details in the pattern surface with ease. Service temperature in the 400
o F range is routine with PT4925 and, with the proper hardener
selection, it will perform very well in cyclic 500 o F temperature
applications. PT4925 does not contain vinyl cyclohexane diepoxide (VCHD)
or other regulated ingredients. Typical uses for PT4925 include foundry
patterns, vacuum form molds, matched dies, compression mold dies,
autoclave fixtures and spacers and other applications where good
stability and thermal conductivity are required.
Three hardeners are listed here for use with PT4925. They provide a range of working times for castings of various thickness. These hardeners are low in viscosity, so they aid in thinning the mixture for best detail reproduction. These hardeners give exceptional high temperature properties, and they are low potential toxicity products. They do not contain methylene dianiline (MDA), or other aniline derivatives. They are non-staining materials, and will not crystallize in normal shipping and storage conditions.
– PT4925-B: Shorter Pot life hardener with good gel at room temperature. For smaller castings with good heat resistance after a post cure. Gel time: 40-50 min.
– PT4925-B1: Longer working time than PT4925-B, for larger castings. Gel time: 3-4 hours.
– PT4925-B2: Very long pot life hardener for large mass castings. Must be heat cured on the pattern. Low viscosity thins the resin well for better pouring characteristics. Gel time: 8-12 hours.
|Viscosity||497000 cps||1700 cps||150 cps||200 cps||D2392|
|Specific Gravity, gms./cc||1.77||1.08||.99||1.01||D1475|
|Mix Ratio, by Weight||—||100 : 8||100 : 10||100 : 10||PTM&W|
|Pot Life, 4 fl oz Mass @ 77°F||—||40 – 50 min.||3 – 4 hours||8 – 12 hours||D2471|
* PT4925 resin is a high viscosity liquid at room temperature. Some
users prefer to warm the resin to lower the viscosity for easier
pouring. This is especially useful where highly detailed castings, or
difficult filling problems are involved. Since heating shortens the pot
life, it is recommended that PT4925 Part B2 hardener be used to give
longer working time for pouring.
HANDLING & CURING
PT4925 has a high aluminum filler content which may settle in long-term
storage. Stir the resin before each use to redisperse any filler that
may have settled. Castings made with Part B and Part B1 hardeners will
gel at room temperature, and, after a good hard gel, the castings can be
demolded for the final heat curing cycle. Care should be taken if the
castings are to be demolded before post curing,
as high temperatures service hardeners typically give somewhat brittle cures at room temperature only. This is not as much a concern with the Part B hardener, but a definite consideration with the Part B1 hardener. The Part B2 is a very slow curing hardener, and castings made with it should be cured entirely on the master pattern. Castings made with PT4925 Part B should be allowed to cure at room temperature on the pattern for a minimum of 18 hours before post curing. Part B1 hardener will require a 24 hour minimum room temperature cure on the pattern before post curing. Hardener PT4925 Part B2 will require longer than 24 hours before post curing, the exact time being determined by the size of the casting and the amount of any bulk filler content. An oven post cure is recommended for all castings for the maximum stability in service. A typical cure cycle would be: Gel for the required time at room temperature, plus 3 to 4 hours at 150 o F, 250 o F and 350 o F. This schedule represents the minimum recommended cure schedule. Longer time at room temperature followed by longer times at smaller incremental increases will usually result in lower shrinkage and less stress buildup in the finished castings.
|Gallon Kit||Pail Kit|
|PT4925 Part A||14 lb.||55 lb.|
|PT4925 Part B||1.15 lb.||4.5 lb.|
|PT4925 Part B1||1.4 lb.||5.5 lb.|
|PT4925 Part B2||1.4 lb.||5.5 lb.|
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
|PT4925 A/B||PT4925 A/B1||PT4925 A/B2||ASTM Method|
|Mixed Viscosity, @77°F, centipoise||178,000 cps||54000 cps||74000 cps||D2393|
|Pot Life, 4 fl. oz. Mass @ 77°F||40 – 50 min.||3 – 4 hr.||8 – 12 hr.||D2471|
|Cured Hardness, Shore D||91 Shore D||91 Shore D||91 Shore D||D2240|
|Specific Gravity, grams, cc||1.69||1.65||1.65||D1475|
|Density, lb./cu. in.||.0612||.0598||.0599||D792|
|Specific Volume, cu. in./lb.||16.4||16.75||16.7||D792|
|Tensile Strength, psi ||8100 psi||8380 psi||9700 psi||D638|
|Elongation at Break, %||1.32 %||1.32 %||1.86 %||D638|
|Compressive Strength, psi||20760 psi||21120 psi||21840 psi||D395|
|Glass Transistion Temperature, DMA:||309°F||365°F||350°F||D4065|
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.