Huntsman Araldite 8579 Resin/Hardener 8579 Structural Adhesive

Araldite® 8579 Resin / Hardener 8579 epoxy adhesive is a solvent-free, thixotropic, cold-setting paste that spreads easily and has good gap-filling characteristics. The cured system is chemical resistant and has good mechanical strength up to 248°F (120°C).

KEY PROPERTIES

• Easy to process
• Gap filling
• Excellent chemical resistance
• Low out gassing
• Temperature resistant up to 120°C / 248°F

PRODUCT DATA

PROCESSING

Pretreatment

The strength and durability of a bonded joint is dependant on proper treatment of the surfaces to be bonded. At the very least, joint surfaces should be cleaned with a good degreasing agent such as acetone, iso-propanol (for plastics) or other proprietary degreasing agents in order to remove all traces of oil, grease and dirt. Low-grade alcohol, gasoline, or paint thinners should never be used. The strongest and most durable joints are obtained by either mechanically abrading or chemically etching (“pickling”) the degreased surfaces. Abrading should be followed by a second degreasing treatment.

Mix Ratio (2.5 to 1) by Weight and Volume

Application of Adhesive

The resin/hardener mix may be applied manually or robotically to the pretreated and dry joint surfaces. Huntsman's technical support group can assist the user in the selection of a suitable application method as well as suggest a variety of reputable companies that manufacture and service adhesive dispensing equipment.
A layer of adhesive 0.002 to 0.004 in (0.05 to 0.10 mm) thick will normally impart the greatest lap shear strength to the joint. Huntsman stresses that proper adhesive joint design is also critical for a durable bond. The joint components should be assembled and secured in a fixed position as soon as the adhesive has been applied.
For more detailed explanations regarding surface preparation and pretreatment and adhesive joint design, visit www.araldite2000plus.com.

Equipment Maintenance

All tools should be cleaned with hot water and soap before adhesives residues have had time to cure. The removal of cured residues is a difficult and time-consuming operation.
If solvents such as acetone are used for cleaning, one should proceed in a well-ventilated area and wear the appropriate protective clothing and equipment to prevent any risks of eye and skin contact.

Times to minimum shear strength (estimated)

Typical cured properties

Unless otherwise stated, the figures given below were all determined by testing standard specimens made by lap-jointing 4.5 x 1 x 0.063 in (114 x 25 x 1.6 mm) strips of aluminum alloy. The joint area was 0.5 x 1 in (12.5 x 25 mm) in each case. The figures were determined with typical production batches using standard testing methods. They are provided solely as technical information and do not constitute a product specification.

Lap Shear Strength (LSS) of typical metal-metal Joints
Cure: 16 hours at 104°F (40°C); Tested at: 77°F (25°C)

Lap Shear Strength – Effect of Test Temperature
Cured for 48 hours at 77oF (25oC) and tested at 77oF (25°C). Load applied 10 minutes after specimen reached Test temperature

Lap Shear Strength – Effect of Immersion
Cured for 48 hours at 77°F (25°C) and tested at 77°F (25°C). Immersion Data after 90 days, unless otherwise indicated

Lap Shear Strength – Effect of Tropical Exposure (104oF (40oC) / 92% RH)
Cured for 48 hours at 77oF (25oC) and tested at 77oF (25°C).

Lap Shear Strength – Effect of Heat Aging
Cured for 48 hours at 77oF (25oC) and tested at 77oF (25°C).

Glass Transition Temperature (Tg), oF (°C) (DMA)
Cure: 24 hours at 77°F (25°C) 183oF (84°C)
Post Cure at 248°F (120°C) for 2 hours 241oF (116°C)

Coefficient of Thermal Expansion (ISO 11359-2)
Cure: 24 hours at 77°F (25°C) 71x10-6 C-1
Cure: 5 min at 176°F (80°C) + 24 hr at RT 37x10-6 C-1

Water Absorption (ISO 294-3) – Eight Day Average
Cure: 24 hours at 77°F (25°C) 0.63%
Cure: 5 min at 176°F (80°C) + 24 hr at RT 0.51%

Tensile Stress (ASTM D638), psi (MPa)
Cure: 24 hours at 77°F (25°C) 3,433 (24)
Cure: 5 min at 176°F (80°C) + 24 hr at RT 4,571 (32)

Tensile Strain (ASTM D638), %
Cure: 24 hours at 77°F (25°C) 0.5%
Cure: 5 min at 176°F (80°C) + 24 hr at RT 0.5%

Tensile Modulus (ASTM D638), psi (GPa)
Cure: 24 hours at 77°F (25°C) 1,111,346 (8)
Cure: 5 min at 176°F (80°C) + 24 hr at RT 1,269,485 (9)

Shrinkage
Cure: 24 hours at 77°F (25°C) 0.04%
Cure: 5 min at 176°F (80°C) + 24 hr at RT 0.28%

Storage

When stored in their original sealed containers at a temperature within 36°F to 104 ºF (2ºC to 40ºC), Araldite® 8579 Resin and Hardener 8579 have a shelf-life of 3 years. Care must be taken to avoid exposing both the resin and the hardener to moisture and air. The performance of the hardener component (hence adhesive) deteriorates if it is exposed to moisture and air over extended period of time. It is therefore, recommended to blanket the Hardener 8579 with dry nitrogen prior to tightly resealing the container after each use.

Handling precautions

Caution
To protect against any potential health risks presented by our products, the use of proper personal protective equipment (PPE) is recommended. Eye and skin protection is normally advised. Respiratory protection may be needed if mechanical ventilation is not available or is insufficient to remove vapors. For detailed PPE recommendations and exposure control options consult the product MSDS or a Huntsman EHS representative.