Bonding Acetal with Adhesive

Joining Techniques and Surface Preparation for Bonding Acetal

For joining acetal to acetal a welding technique such as a heated tool, hot gas, spin, or ultrasonic welding is common. However, if you are bonding acetal to other materials, such as metal, then an industrial adhesive is a good option. As the material seems to have quite a lubricated surface, then roughening it up will help improve adhesive keying and bond strength. Either grit blast, wire wool, red ScotchBrite, grit paper, or emery cloth.

Selecting an Adhesive

Permabond TA46XX Series of structural acrylic adhesive bond acetal and provide excellent water resistance.

If water resistance is not required, cyanoacrylate adhesives, when used in conjunction with Permabond POP Primer can be considered.  For extra toughness, impact resistance, and temperature resistance, Permabond 731 is a good choice.

Heat cure epoxies (such as Permabond ES5741 for difficult plastics) also perform well.

Threaded parts can be bonded with an anaerobic threadlocker (providing an activator is used).

Acetal

Acetal is a popular thermoplastic; its use spans a number of industries. This plastic is fairly low cost and has good structural properties – it is often used instead of metal. It is very high strength, with good impact resistance, low rate of water-absorption, good chemical resistance (even against solvents), high dielectric strength and good flame resistance. Acetal is available in a number of different blends e.g.

• Glass filled
• PTFE filled for improved slip properties (low friction)
• Toughened, abrasion resistant
• UV stabilised, pigmented
• Antistatic
• Conductive

A common trade name for acetal is Delrin (DuPont).  Acetal material is often used for cogs, gears, plastic bearings, conveyor rollers, impellers etc. where the low friction surface is particularly important.  Pump housings, motor housings and some pipe fittings may also incorporate acetal parts.

For more information on bonding acetal using industrial adhesives, please contact the Permabond technical team here.