Automated Two-Component Epoxy Dispensing for Implantable Medical Devices

Medical device manufacturers must establish and follow quality systems to ensure that their products consistently meet specifications. They must also ensure that their products are built using controlled processes. It can be challenging to consistently meet these requirements when highly manual methods are used during manufacturing. In many cases, process automation delivers results that meet quality, traceability, and repeatability standards.

It is particularly important to achieve consistent results when manufacturing Class III medical devices such as pacemakers and defibrillators. Nordson ASYMTEK has successfully supported a medical device manufacturer by automating a manual, two-step process for dispensing a two-component epoxy to encapsulate pacemaker assembly components. The automated solution includes the use of a Quantum® Fluid Dispensing System that is equipped with an Angstrom meter.

Manual Process

The previous process required an operator to manually fill a syringe for each fluid type (A & B), fit it with a dispensing needle and receiver head, and then dispense the fluid to complete the encapsulation process. At the beginning, a time/pressure controlled filling station was used to manually push the part A and part B materials through a static mixer and into an empty 30-cc syringe. When the syringe was full, the operator fitted the syringe with a dispensing needle and receiver head, held the pacemaker, positioned the needle tip over the encapsulation area, and dispensed the fluid. With this manual process, it was not possible to track exactly where the fluid was dispensed, how quickly it filled the cavity, or how much fluid was dispensed - these process variables depended entirely on the individual operator.

Automated Solution Details

In the new, automated process, pacemaker assemblies are placed in a custom fixture that gets conveyed into a Quantum system equipped with an Angstrom meter. The Angstrom meter then automatically mixes and dispenses controlled amounts of a two-part epoxy to complete the encapsulation process.

Applications Corner 2016-11 Newsletter Story - Automated Two-Component Epoxy Dispensing for Implantable Medical Devices

The Angstrom meter is designed to dispense two-part adhesives, epoxies, and sealants at precisely controlled volumes and flow rates. An integral part of the Angstrom is its rotary spool valve that switches between dispense and reload positions. At rest the Angstrom’s two metering rods are fully retracted with the spool valve in the reload position. When a dispensing command is received from the Quantum system, the spool valve switches into the dispense position and the servo motor begins driving both metering rods downward into their respective cylinders - proportionally displacing fluid A and fluid B out and into the static mixer. The total volume of fluid dispensed is proportional to the total volume displaced by the rods, which is controlled by the total number of encoder counts. In addition, the amount dispensed can be controlled through weight control and time commands in Fluidmove® software on the Quantum dispenser. When dispensing is completed and a refill command is received from the Quantum system, the spool valve switches back into the load position and the metering rods are fully retracted allowing fluid A and fluid B to refill the cylinders in preparation for the next dispense.

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