Fluid dispensing explained

This article explores a range of dispensing techniques that can lead to better process control in the biosciences.

During the assembly of medical devices, point-of-care diagnostics, near-patient testing products and other life sciences applications, it is essential that dispensing of UV-cure adhesives, cyanoacrylates, silicones, and other fluids are accurately and consistently deposited.

Accuracy and repeatability

Shot-to-shot repeatability and accuracy are critical factors in fluid dispensing, and with particular importance in the manufacture of life sciences products and devices.

Automated robotic dispensing has evolved to support the needs for higher throughput in the assembly of medical devices, point-of-care diagnostics, and near-patient testing products by developing specialised dispensing technologies for automated in-line and near-line assembly.

These technologies provide operators with the ability to set the time, pressure, and other dispensing parameters for an application that improves process control and ensures the right amount of fluid is placed on each part.

Robotic dispensing

An important feature of precision robotic dispensing is Automated Optical Inspection (AOI). When coupled with CCD cameras and confocal lasers, vision-guided automation platforms provide optical assurance of fluid deposit volume and placement accuracy ensuring a conforming deposit.

Non-contact jet dispensing

There are two basic types of fluid in-line micro-dispensing techniques: classic needle-based contact dispensing and non-contact jet dispensing. While the best method is ultimately determined by the material and application at hand, for many automated fluid dispensing processes, high-speed jetting technology is a popular alternative to traditional, needle-based contact dispensing.

Better fluid dispensing

Point-of-care diagnostics and near-patient testing products both help doctors make critical decisions, and help patients monitor their health. These devices include HIV tests, blood tests, and pregnancy tests. One system that performs exceptionally well for this application is the proprietary PICO Pulse XP jetting system, due to its fast-dispensing speed and high precision.

Vision guided dispensing

Vision has been used in fluid dispensing applications for more than two decades, and is becoming more prominent as robots, and their control software, get smarter. It permits robotic fluid dispensing systems to deliver faster production cycles, and removes the guesswork from the dispensing process. The latest evolution of fluid dispensing robot systems – exemplified in Nordson EFD’s GV, RV, EV, PRO and PROPlus Series models for 3-axes and 4-axes applications – with their advanced software and vision-guided capability, bring repeatability and precision to automated dispensing systems.

Benchtop fluid dispensing

Medical devices sometimes warrant a more personalised and manual fluid dispensing approach in their assembly, compared to employing a more automated, robotic system. Often, the geometry of the parts is too complex to make robotic automation a viable option, or the production volume is too low to warrant the investment.

Benchtop fluid dispensing has proven to be a highly workable and reliable method for  assembly of medical devices,  and the UltimusPlus line of pneumatic benchtop dispensers from Nordson EFD, was designed to meet stringent fluid dispensing needs of today’s highly precise medical device manufacturing.

Recent Issues