ARALDITE® 2021-1 A/B

• Working time: 4 - 5 minutes
• One to one volume mix ratio
• High peel strength
• Multi-purpose
• Excellent bond to a wide range of plastics, composites and metals
• Suitable for service at temperatures up to 212°F (100°C)

• Rapid curing
• Toughened
• Multi-purpose
• Excellent bond to a wide range of plastics, composites and metals
• Suitable for service at temperatures up to 100°C
• Good Lap Shear Strength on a variety of substrates
• Toughness & Resilience
• Short open time
• Non sagging & gap filling
• Temperature resistance up to 100C
• Tolerant to non ideal surface preparation

• Multipurpose, versatile/universal use.
• Resistant to vibrations & dynamic loading, impact resistance, assembly of dissimilar substrates.
• Fast handling, rapid curing, increased productivity. Suitable for high volume runs.
• Easy processing, vertical application possible.
• Continuous operating temperature of end-part from very low temperatures to 100°C.
• Easy processing, increased productivity.

Pretreatment:

The strength and durability of a bonded joint are dependent 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. ARALDITE® 2021-1 A/B structural adhesive is available in cartridges designed for use with disposable 18- 21 elements mixing nozzles and can be applied as a ready to use adhesive.

Application of adhesive:

The resin/hardener mix may be applied manually or with an automated dispensing equipment to the pretreated and dry joint surfaces. A 0.002 to 0.004 in (0.05 to 0.10 mm) thick adhesive layer will normally impart the greatest lap shear strength to the joint. A proper adhesive joint design is also critical for a durable bond. The joint components should be assembled and maintained in a secure position as soon as the adhesive has been applied. For more detailed explanations regarding surface preparation and pretreatment, adhesive joint design, and the dual syringe dispensing system.

Equipment Maintenance:

All tools should be cleaned with hot soapy water before the adhesive residue has had time to cure. The removal of cured residue is a difficult and time-consuming operation. If solvents such as acetone are used for cleaning, operators should take the appropriate precautions to avoid skin and eye contact.

Cure times to reach minimum shear strength:

Typical Physical Properties:

Unless otherwise stated, the data were determined with typical production batches using standard test methods. They are typical values only, and do not constitute a product specification. The figures below were all determined by testing standard specimens made by lap-jointing 4.5 x 1.0 x 0.063 in (114 x 25 x 1.6 mm) strips. The bond area was 0.5 x 1.0 in (12.5 x 25 mm) in each case.

Average of 3 test specimens lap shear strength, metal-metal joints. Substrates were degreased with IPA.

Average of 3 test specimens lap shear strength, plastic-plastic joints. Substrates were lightly abraded and degreased with IPA. 

Average of 3 test specimens lap shear strength on primed aluminum substrates. Substrates were degreased with IPA, cured at 40°C for 16 hours and tested at 23°C, after immersion in 23°C media.

Average of 3 test specimens lap shear strength on primed aluminum substrate versus tropical weathering, 92% RH at 40°C. Substrates were degreased with IPA, cured at 40°C for 16 hours and tested at 23°C. Initial, psi

Average of 3 test specimens lap shear strength on primed aluminum substrate versus temperature. Substrates were degreased with IPA and cured at 40°C for 16 hours and tested at different temperature.

Additional properties:

• Pretreatment: The strength and durability of a bonded joint are dependent on proper pretreatment of the surfaces to be bonded, however the methacrylate adhesives can be used effectively with little surface preparation. Ideally 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 (petrol) 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.

• 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 an suitable application method as well as suggest a variety of reputable companies that manufacture and service adhesive dispensing equipments. A layer of adhesive 0.25 to 0.5 mm thick will normally impart the greatest lap shear strength to the joint. For some metals like mild steel or stainless steel, a higher joint thickness may be necessary to reach satisfactory results. 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.
• 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 MEK are used for cleaning, operatives should take the appropriate precautions and, in addition, avoid skin and eye contact.

Typical times to minimum shear strength

ARALDITE® 2021-1 A/B may be stored for 24 months at 2°C to 8°C provided the components are stored in the original sealed containers. The expiration date is indicated on the packaging. The product may be placed at room temperature before use, the total time at room temperature should not exceed 6 months. Long term exposure above 25°C will reduce the shelf life of the product.

Our products are generally quite harmless to handle provided that certain precautions normally taken when handling chemicals are observed. The uncured materials must not, for instance, be allowed to come into contact with foodstuffs or food utensils, and measures should be taken to prevent the uncured materials from coming in contact with the skin, since people with particularly sensitive skin may be affected. The wearing of impervious rubber or plastic gloves will normally be necessary; likewise the use of eye protection. The skin should be thoroughly cleansed at the end of each working period by washing with soap and warm water. The use of solvents is to be avoided. Disposable paper - not cloth towels - should be used to dry the skin. Adequate ventilation of the working area is recommended.