Jetting 101 and How to Choose Between Pneumatic and Piezoelectric Technology

Part One: Choosing the Right Jetting Technology Can Positively Impact your Manufacturing Process

In the manufacturing world, there are multiple fluid dispensing solutions for a single application. In this blog post, we’ll identify the key differences between contact vs. jetting valves and pneumatic and piezoelectric jetting technology to help simplify the task of selecting the right solution.

Contact vs. Jet Dispensing

Contact valves are dispensing technology that requires Z axis movement to apply a fluid deposit onto a substrate. This is often seen as the traditional method of dispensing although it is still very much applicable in many applications. Contact dispensing valves come in a wide range of styles including spray, micro, needle, diaphragm, aseptic, high flow, piston, radial, and more.

Having many specialty options gives manufacturers the ability to accurately dispense for specific applications such as applying fluid inside cylindrical parts, spray marking systems for color coding, and so much more.

These valves work well with highly abrasive pastes or cyanoacrylates that can be tricky to jet. They also can be more efficient at dispensing thicker lines, which may take several extra passes for jetting valves because jet valves are designed more for speed and smaller deposits.

Jetting valves are dispensing technology where no Z axis movement is required. Instead, your fluid “flies” or jets out of the valve, which is above the part. This makes jetting perfect for fragile or complex parts with varying heights.

These valves are especially useful in high volume applications or where any time-saving processes are needed. With the elimination of a Z axis, jetting valves can dispense at speeds of up to 1000Hz (deposits per second) continuously and 1500Hz bursts. Speed capabilities are simply unmatched when compared to contact valves, which can take nearly 14 times longer to dispense the same pattern.

For more info on this topic, you can check out our contact versus non-contact dispensing blog post. Download the Contact vs. Jet Dispensing White Paper for more technical information, tables, application examples, and other useful resources designed to help you decide which method is best for your application.

Pneumatic vs. Piezoelectric Jet Technology

If you’ve determined that jet dispensing is the ideal solution for your application, it’s time to look at the technology available. At Nordson EFD, we have two types of jetting systems. Our Liquidyn jet valve series that uses electro-pneumatic technology and includes our P-Dot and P-Jet valves and our PICO jet valve series that uses piezoelectric technology and includes our PICO Pµlse® and PICO Pµlse XP valves.

In this section, we’ll uncover the main differences between pneumatic and piezoelectric jetting technology and the cases when one may be more beneficial than the other.

Accuracy

With pneumatic technology, you’re using air pressure to move the tappet ball up and down to strike against the seat, forcing the fluid out when jetting. With piezoelectric technology, you’re using up to 120 volts to rapidly expand the piezo stack to generate kinetic energy inside the valve to eject out fluid. Since the energy mechanics with piezo technology are functioning on electricity within the valve itself instead of outside pressure, this makes it the more accurate solution of the two.

Volume

Deposit size is an integral part of choosing your valve. Our pneumatic Liquidyn jet valves can jet micro-deposits as small as 3 nL while our piezoelectric PICO jet valves can jet micro-deposits as small as 0.5 nL. P-Dot and P-Jet valves are better suited for larger deposits and offer nozzle sizes up to 1.4 mm. PICO jet valves can achieve smaller deposits because of their precise control of stroke and smaller nozzle size, which are available in multiple sizes ranging from 20 µm up to 600 µm.

Fluid Type

The type of fluid you’re working with can pinpoint which valve works better for your application. Typically, when you’re dispensing higher viscosity fluids, such as 100,000cps or higher, we recommend our pneumatic Liquidyn jet valves. Our P-Dot Series is suitable for thicker adhesives, lacquers, oils/greases, silicones, and fluxes and our P-Jet Series is ideal for cyanoacrylates, anaerobics, solvents, greases/oils, and silicones. Both are equipped with a force multiplier, allowing them to deposit thicker fluids.

Speed

In terms of speed, our pneumatic Liquidyn jet valves are capable of jetting at speeds up to 280Hz per second while our piezo PICO jet valves can jet at speeds up to 1000HZ. When working with high-volume applications, the PICO valves have the clear advantage since they can jet nearly 4 times faster than our Liquidyn valves.

In Conclusion

In the end, all of the fluid dispensing technology discussed in this blog post has a purpose in the manufacturing world. With jetting technology specifically it’s important to speak with an experienced application specialist who can determine if jetting is the right fit. You may even require a complimentary application test with our jetting technology to determine if jetting will work for your specific application requirements.

Please don’t hesitate to email us at [email protected] if you have any questions or would like to set up an application test.

 

 

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