Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Technologies
- Product Families
Features & Benefits
- Ready-to-Use Product Features
- Features
Magna-Tac E645 has proved practical as an adhesive/dielectric in the fabrication of magnetic accelerator units such as cyclotrons and cosmotrons, because so little adhesive is needed to accomplish a strong bond which resists shear stress. Magna-Tac E645 is a strong metal-to-metal adhesive. Because of its excellent mechanical strength plus its resistance to many solvents, water, atmospheric conditions and temperature changes, this adhesive is adaptable to many industrial uses. It is particularly suited to the bonding of large surface areas and mass production processing.
Applications & Uses
- Applications
- Application Area
- Application Method
- Compatible Substrates & Surfaces
- Cure Method
- Methods of Stack Lamination
Methods of Stack Lamination
Most companies develop their own techniques to bond stack laminates most efficiently. The three most common are:
- Coil or Stack, then Vacuum Impregnate: Stack cleaned metal in flat sheets separated on a mandrel or in coils. In a pot or kettle, under vacuum, remove all entrapped air. Pressure-force adhesive between layers. Drain. Apply vacuum to remove solvent vapors. Heat cure. Cut to shape if required.
- Precoat, then stack: Stack parts to shape and clean. Deposit a thin film of adhesive on each surface to be bonded. Dry. Store if necessary. Assemble into stack and heat cure.
- Coat, Stamp & Stack: Spray or roll coat adhesive onto both sides of flat sheets. Dry. Stamp to shape. Lay up adhesive-coated laminates and heat cure.
- Application
Adhesive Preparation
In order to convert the basic formulation components into a tough, hard, strong adhesive film, thoroughly mix Magna-Tac E645 Part I with the Part II by weight in the following proportions:
By Weight
- MagnaTac E645 Part 1 - 100 parts
- MagnaTac E645 Part 2 - 30 parts
By Volume
- MagnaTac E645 Part 1 100 parts
- MagnaTac E645 Part 2 35 parts
Reducing the viscosity of the mixed adhesive
While it is not mandatory, MagnaTac E-645 is commonly diluted with a solvent to reduce its viscosity. This allows for easier application of the adhesive. Once part 1 and part 2 have been mixed, MagnaTac E-645 can be diluted with Cellosolve, methyl ethyl ketone (MEK), toluene, acetone, or a 50/50 mixture of acetone and isopropyl alcohol.
Applying the adhesive
Mixed Magna-Tac E645 can be applied by brushing, spraying, dipping or roller coating. For very small parts, it can be dispensed easily through a hypodermic needle. For maximum adhesive, all surfaces must be perfectly clean and thoroughly degreased. For improved strength and chemical resistance, sandblast or treat the surfaces chemically. These treatments will vary according to the material, of course. Operators' hands must be free from grease or oil while handling coated and uncoated parts.
Cure Time
The adhesive must be thoroughly dried before curing. Drying may be accomplished at room temperature or by forced drying in circulating air ovens. If all of the solvent is not removed before curing, blisters or weakening of the adhesive film will result. Thick or highly diluted films will take longer to dry. At normal room temperatures, air drying may take 4-8 hours. For best results, force dry at 125F for 60 mins or at 200F for 10 minutes. Do not dry at temperatures above 250F (adhesive will start to cure at that temp). The adhesive dries to a tack free surface at room temperature. Coated parts may be stored before curing for periods of up to 6 months at room temperature. However, the adhesive film must be clean and dry.
Curing Pressure
Pressure is not needed to affect the bond but is essential that the coated surfaces be in complete and intimate contact over the entire area of the materials being bonded. Accordingly, sufficient pressure must be applied to assure such contact. The specific amount of pressure needed will vary, depending upon the flatness of the components, porosity, resiliency, etc.
Supplemental Information
Fungus resistance: MagnaTac E-645 after cured is fungus inert and is not conducive to fungus growth. It is, however, necessary to conduct specific tests under service conditions to determine actual compatibility with end use application.
- Heat Curing
The hardening agent (Part II) of MagnaTac E645 is reactive above 250F. Normal cure temperatures at the glue line range from 265F-400F. Curing temperature below 375F are recommended because it is practically impossible to degrade the adhesive in that range even if the recommended curing time is exceeded. Before curing, Magna-Tac E645 is thermoplastic and flows freely as the temperature is raised. This allows the films to fuse to a stronger bond and assures complete "wetting" of the materials being bonded. For certain specialized applications, however, some users prefer to retard the normal flowout. This can be done by partially curing the adhesive at contact pressure only for about 1/4 to 1/2 the "minimum gel time" shown in figure 1. Any of the normal time and temperature cycles listed may then be used for subsequent curing... but with slightly increased pressure.
Heat Curing Schedule
Glue Line Temperature Minimum Gel Time Minimum Cure Time Maximum Cure Time
266°F or 130°C 40 min 14 hours none 284°F or 140°C 32 min 7 hours none 302°F or 150°C 20 min 4 hours none 320°F or 160°C 15 min 2 hours none 338°F or 170°C 10 min 1.5 hours none 356°F or 180°C 8 min 1 1 hour none 374°F or 190°C 6 min 45 min none 392°F or 200°C 4 min 30 min 24 hours 428°F or 220°C 2 min 19 min 60 min The figures refer to the temperature of the adhesive film. Allow sufficient time for the stack to attain the correct temperature. The time required for cure depends on the temperature selected, on the mass of metal and on the heat capacity of the metal in the laminate. The temperature chosen depends on the heat sensitivity of the materials being bonded and time limitations in production scheduling. If the maximum cure time is exceeded, over-curing which may cause failures - can result.
- Base
Modified epoxy
Properties
- Diluent
- Solvent
- Typical Properties
- Composition
| Value | Units | Test Method / Conditions | |
| Viscosity (Part A) | 6000.0 | cps | — |
| Viscosity (Part B) | Water thin | — | — |
| Weight Per Gallon (Part A) | 9.3 | lbs | — |
| Weight Per Gallon (Part B) | 8.4 | lbs | — |
| Compressive Strength | Approx. 60,000 | psi | — |
| Flash Point | 151.0 | °F | — |
| Modulus | 5.0 x 10⁵ | psi | — |
| Linear Coefficient Of Expansion | 65 x 10⁻⁶ | inches/inches/°C | — |
| Thermal Conductivity | 5000 x 10⁻⁷ | calories/(second)(square cm)(°C)(cm) | — |
| Hardness | 75.0 | Shore D | ASTM D 2240 |
| Tg | 114.0 | °C | — |
| % TML (Cured 1 hr at 100°C, in air followed by 4 hrs at 180°C, at 10⁻² Torr Vacuum) | 0.5 | — | NASA Outgassing Technical Note TND-8008 |
| Dielectric Strength | 400.0 | volts per mil | — |
| Dielectric Constant (106 cycles per second at 20°C) | 3 - 4 | — | — |
| Loss Factor (20°C) | 0.06 | — | — |
| Value | Units | Test Method / Conditions | |
| Solid Content (Part A) | 77.0 | % | — |
| Solid Content (Part B) | 12.0 | % | — |
Regulatory & Compliance
- Certifications & Compliance
Technical Details & Test Data
- Typical Lap Shear
Values obtained when Magna-Tac E645 is used to bond 0.064" etched 2024T3 aluminum alloy to itself in a 1/2 overlap are as follows:
Test Temperature Av. Lap Shear, psi
-67°F 2800 77°F 4000 180°F 3000 260°F 1000 300°F 800 400°F 200
Storage & Handling
- Shelf Life
- 1 year