Can I use any dispensing tip with any fluid?

Although in theory, any dispensing tip can be used with any fluid, the success of an application often depends upon choosing a tip that addresses certain fluid challenges.

The following fluids benefit from using specific types of dispense tips:

• Thin fluids
• High viscosity fluids or particle-filled materials
• UV-sensitive adhesives
• Cyanoacrylates

Dispensing tips for thin fluids

Thin fluids can drip during the dispensing process. Dripping can be caused by overly high fluid velocity and by wicking, which occurs when capillary action causes thin fluids to creep up the outside of the dispensing tip.

The right dispensing tip can address both issues.

• A crimped cannula (see Figure 2) can slow the velocity of a thin fluid, leading to better deposition control.
• Coating the cannula with polytetrafluoroethylene (PTFE, or Teflon) disrupts capillary action, helping to prevent wicking.

For more information, see What is the best dispensing tip for a thin fluid?

Dispensing tips for high-viscosity fluids or particle-filled materials

Tapered polyethylene tips are the best choice for thick pastes or particle-filled materials. With gradual narrowing, tapered tips prevent sudden fluid compression during dispensing that can change the material properties of the fluid (see Figure 1).

For more information, see What is the best dispensing tip for a thick paste?

Nordson EFD’s SmoothFlow tapered tips are designed to deliver higher flow rates even with high-viscosity fluids.

Dispensing tips for UV-sensitive adhesives

Translucent tips can pass UV light, causing premature curing of UV-sensitive materials. This can lead to clogged dispensing tips, impeding or even stopping production altogether. To prevent this issue, look for tapered plastic tips made with UV-blocking additives.

Dispensing tips for cyanoacrylates

Cyanoacrylates are a special class of quick-curing adhesives. They’re available as both medium-viscosity fluids (gels) and low-viscosity fluids. Because of their quick-curing nature, cyanoacrylates must be used with specific types of dispensing tips, or they will block the dispense tip.

To successfully dispense medium-viscosity cyanoacrylates, choose a tapered plastic tip for better flow.

To successfully dispense low-viscosity cyanoacrylates, look for a tip with a combination of a PTFE lining, which resists clogs, and a crimped tip to slow velocity for better dispensing control (see Figure 2).

For more details on dispensing cyanoacrylates, see What is the best dispensing tip for a cyanoacrylate?

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.