Bonding Nylon/Polyamide with Industrial Adhesive
Polyamide (commonly called Nylon which is a DuPont tradename), is a thermoplastic material widely used in a number of applications across various industries. Special blends are often available with features such as high lubricity, flexibility, and flame retardant properties. Often, Nylon is glass-filled to give extra strength and stiffness properties. It often has a “silky” appearance and it has quite a high melting point – making it a popular material for engineering applications.
Difficulties Bonding Nylon
Sometimes bonding Nylon is difficult because the surface can have a “greasy” feel to it (due to slip additives). Even wiping the Polyamide surface clean with an alcohol-based cleaner will show little improvement as the slip additives continue to migrate to the surface. It is possible to “dry-out” Nylon before bonding – leaving it in the oven at 60°C for several hours or overnight will reduce this issue.
Surface Preparation for Bonding Nylon / Polyamide (PA)
It is a good idea to give surfaces a wipe off with a clean rag and isopropanol alcohol to remove any processing lubricants, dust, grease or other contamination. Mechanical abrasion (e.g. using gritpaper, wire wool, red Scotchbrite etc.) will help increase mechanical keying of the industrial adhesive and improve bond strength.
Selection of a Suitable Industrial Adhesive for Bonding Nylon
Anaerobic adhesives: These are limited to specific co-axial or threaded, close fitting joints and require a reactive metal surface to trigger the cure (or use of an anaerobic activator). They are a good choice for threadlocking or sealing but not suitable for bonding Nylon structural joints.
Cyanoacrylate adhesives: These work well on Nylon parts but accelerated aging tests are recommended to check long term durability on certain blends of Polyamide. Using a polyolefin primer on the surface before bonding shows no increase in strength and is therefore not recommended.
Epoxy adhesives: Choosing a softer, more flexible epoxy would be recommended for bonding Nylon, as Nylon is a fairly soft material.
Two-part polyurethane adhesives: These work very well when bonding Nylon, especially as they are fairly flexible and have high peel strength.
Structural acrylic adhesives (including methyl methacrylates): These industrial adhesives work well on most Polyamide blends, combining both rapid bond strength development with high structural strength.
UV-cure adhesives: Generally not recommended for bonding Nylon, as Nylon blocks UV light and would prevent proper curing. If curing through a clear substrate onto Nylon then it could be considered.
For more information on bonding Nylon (Polyamide) or other industrial adhesive questions, please contact the Permabond technical team here.