Loctite Instant Adhesives

What is an instant adhesive?

Referred to technically as cyanoacrylate adhesives, and commonly referred to as superglues, these products are used when time is of the essence. Instant adhesives cure very quickly when confined between close fitting surfaces, exhibiting excellent adhesion on most substrates and especially on small to medium sized parts.

Advantages of instant adhesives

Instant adhesives can be used to bond a variety of dissimilar materials, and are generally clean and easy to apply. Coupled with their fast positioning, it makes them ideal for a variety of applications, including medical and automotive.
Additional benefits from Loctite instant adhesives include their high strength on very small bond faces, their lack of solvents, and not requiring complex part geometrics.

Application

You should be careful to apply the instant adhesive correctly, however, product selection also impacts on the application of the product itself. Gel products are suitable for vertical or overhead surfaces ensuring they do not drip and remain in place during cure. In addition, low odour adhesives and low bloom adhesives ensure that cosmetic appearance is maintained

Performance

Each Loctite instant adhesive is designed with a particular application type in mind. Consideration should be given to products suitable for flexible or bending loads, high temperature use, shock and impact resistance and gap filling applications.

Substrate

As with most adhesives, the substrates to be bonded are a key factor in choosing the right product. The Loctite instant adhesives range contains products specifically designed to bond plastics as well as metals, wood, fabric, leather and paper. With the use of the correct Loctite Activator, some Loctite instant adhesives can be used on difficult to bond substrates such as polypropylene, polyethylene and PTFE.

Hybrid Adhesives

The technology of Loctite hybrid adhesives opens up new applications for instant adhesives in the world of structural bonding. Hybrid adhesives combine the fast bond times of traditional instant adhesives with the strength and adhesion properties of traditional methyl methacrylate and acrylic adhesives.

Surface Preparation

Correct surface preparation is key before any bonding application, and the use of instant adhesives is no different.

Loctite recommend the use of Loctite SF 7063 or Loctite SF 7070 to degrease and clean the surfaces to be bonded prior to application.

Loctite SF 7063 is a general-purpose product for cleaning and degreasing any kind of surface or machinery component before proceeding with a repair or assembly job involving Loctite adhesives. It is a solvent-based cleaner and the product leaves no residue. Loctite 7063 removes most greases, oils, lubrication fluids and metal cuttings.

Loctite SF 7070 is a non-aqueous, hydrocarbon based, non-CFC solvent designed for cleaning and degreasing of surfaces to be bonded with Loctite adhesives. The product is used as a final pre-assembly cleaning treatment to remove most greases, oils, lubrication fluids, metal cuttings and fines from surfaces to be bonded.

All components should be dried before application of the adhesive.

Storage

Applying Loctite instant adhesives correctly starts on delivery. For optimum performance, these products should be stored in the fridge, ideally between 2°C and 8°C. Storage outside of these temperatures can adversely affect product properties.

Activation

If you are applying a Loctite instant adhesive where cure speed is unacceptably long, or the substrate is difficult to bond to, it is recommended that an activator is used.

Various products are available:

• Loctite SF 770 – a heptane based polyolefin primer for difficult to bond plastics.
  
• Loctite SF 7458 – a general purpose activator for all substrates with good aesthetic characteristics.
  
• Loctite SF 7455 – a post applied, colourless activator for all substrates.
  
• Loctite SF 7452 – an acetone based activator providing excellent cosmetic appearance characteristics.
  

Application

To aid in the application of Loctite instant adhesives, dispensing needles in a variety of gauges are available that can be applied directly onto the bottles themselves. These needles improve control when dispensing the adhesive, especially on smaller components.