What is the best dispensing tip for a cyanoacrylate?

Cyanoacrylates are quick-curing adhesives widely used across industry. They can be challenging when used in precision micro dispensing systems. Those same fast-curing properties that make cyanoacrylates so useful can also cause the material to harden before it reaches the work piece, clogging the tip or even blocking it entirely. The right choice of dispense tip can address these issues, leading to more accurate, reliable processes.

How to choose a dispense tip for cyanoacrylates

Cyanoacrylates are available in a variety of viscosities, ranging from thin fluids to gels. This makes it easier to find a version that best suits the application of process parameters, but it also means that there is no single ideal dispensing tip.

Here are our guidelines for selecting the best dispense tip for your cyanoacrylate dispensing application:

For low-viscosity cyanoacrylates, use a PTFE-lined dispense tip

Polytetrafluoroethylene (PTFE, a.k.a. Teflon) is a hydrophobic, highly stable nonstick coating. Use PTFE-lined dispense when dispensing low-viscosity cyanoacrylates. The PTFE lining helps prevent adhesion, inhibiting clogging.

PTFE-lined dispense tips have crimps that restrict the flow of low-viscosity cyanoacrylates, improving control over the dispensing process.

Figure 1: Nordson EFD’s Optimum PTFE-lined tips are designed specifically for micro dispensing low-viscosity cyanoacrylates. The lining prevents clogging inside the metal cannula and the crimp slows material flow for better control of deposition.

For thicker gel-type cyanoacrylates, consider a tapered dispense tip

Gel-type cyanoacrylates are also subject to clogging, but they present the additional challenge of higher viscosity. To ensure smooth flow of these thicker materials, look for polyethylene tapered dispense tips. Polyethylene doesn’t react with cyanoacrylates or lead to premature curing and clogging. The gradual taper of the shape increases control over dispensing without large changes in pneumatic pressure.

Figure 2: Nordson EFD’s SmoothFlow tapered tips are designed to deliver higher flow rates even with thicker gel cyanoacrylates. Because they are molded from polyethylene, they do not react with cyanoacrylates or cause premature curing.

To recap, use PTFE-lined tips when dispensing low-viscosity cyanoacrylates and polyethylene tapered dispense tips when dispensing gel-type cyanoacrylates.