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How to Choose the Right Dispensing Needle for your Fluid Application

When Accuracy Matters, Be Sure Not to Overlook this Important Aspect of Your Dispensing Process

15 November 2017

By Tom Muccino

Sometimes taking a closer look at even the smallest aspect of an assembly process can deliver big returns in terms of improving manufacturing throughput and lead times. Even something as small as checking to make sure operators are using the correct dispensing tips (also known as dispensing needles or nozzles) for the fluid being dispensed.

Each assembly fluid, from thick greases to pourable adhesives to thin solvents, have certain properties to consider. Knowing these properties will help you select the right type of dispensing needle for an application.

Some people ask why there are so many types of dispense tips. The reason is simple. It’s because there are so many types of fluids with different properties for different application requirements. Using the wrong dispensing needle can increase your rework, rejects, and your cycle rates – leading to poor part quality and an inefficient production process.

That’s why Nordson EFD created a series of short How-To videos to help you understand a few of the different styles available and how to choose the right one for your fluid type for improved process control.

When Dispensing Most Fluids

The most common dispensing needle is the general purpose tip. This is the workhorse of the group because it can dispense nearly any kind of assembly fluid. Just because it can dispense nearly any type of fluid, however, doesn’t mean it is the best choice for your fluid.

Watch this video to get a brief overview of the different types of dispensing needles and tips available.

When Dispensing Low-Viscosity or Thin Fluids

Typically, a small diameter general purpose tip is best because of its choke point, which restricts the flow of thin fluids for better process control. However, when dispensing solvents, it’s better to choose a PTFE-coated dispense tip because of a special outer coating that prevents the fluid from wicking up the outside of the cannula, thus improving deposit accuracy and repeatability.

Thin cyanoacrylates (also known as super glues or instant adhesives) require special PTFE-lined tips due to the fast-curing nature of the fluid. Watch this video to learn more about choosing the right dispensing needles, including chamfered tips, for low-viscosity assembly fluids.

When Dispensing Medium- to High-Viscosity or Thick Fluids

SmoothFlow™ tapered tips are generally the best type of tip to use for thicker viscosity fluids because they promote flow, which helps you dispense a greater number of precise, consistent fluid deposits in the shortest amount of time.

Tapered tips allow you to lower the pressure on your pneumatic fluid dispenser. You can lower your pressure from 80 psi (6 bar) using a general purpose tip to 30 psi (2 bar) using a SmoothFlow tapered tip. This is very important when you’re dispensing filled materials because high pressure causes filled materials to separate in the syringe barrel.

Using a tapered tip when dispensing thick fluids helps operators apply deposits faster than with a general purpose tip. This helps improve yields and productivity in your dispensing application. Nordson EFD tapered tips also contain a UV-blocking agent that prevents UV-cure materials from curing inside the dispensing nozzle.

Watch this video to learn more about the best tips for medium- to high-viscosity materials.

When Something Goes Wrong

It’s important to note that not all dispensing needles are of equal quality. Though one company’s dispensing tips may look identical to another company’s dispensing tips, make sure the company you purchase from adheres to a stringent quality inspection process to ensure no burrs or molding flash alter the consistency of your fluid deposits or contaminate your material.

Also consider whether your dispensing components, including the dispensing needle, syringe barrel, piston, and adapter assembly, are designed to work together to deliver the most accurate, consistent fluid deposits possible with minimal fluid waste. This can add up to considerable savings over time.

All Nordson EFD dispensing components are free of flash and burrs and are manufactured in our silicone-free production facility in the U.S. They are also certified for industrial use. Each hub is designed with flush mating of the hub to the cutoff for smooth fluid flow and to prevent trapped air, which can cause dripping and drooling.

If you’d like to try Nordson EFD dispensing tips and needles, please feel free to request a free sample. If you have any questions about how to improve your dispensing process, don’t hesitate to email us at marketing@nordsonefd.com.

Tom MuccinoAbout Tom Muccino

Tom Muccino is a Zone Manager at Nordson EFD. He manages the sales team located in the Midwest to the West Coast of the U.S. and Canada. Tom has more than 30 years of fluid dispensing expertise. He joined Nordson EFD in 1987.


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