Global MRI Manufacturer Improves Process with Graco Solution

If you’ve ever broken a bone or needed a thorough diagnostic workup, there’s a good chance your doctor ordered a series of MRI scans. MRI machines are some of the most complex and capable medical diagnostic tools in the world. Just a handful of companies have the expertise and capacity to design and manufacture these 100-ton behemoths.

Graco distributor Air Power, Inc., was contacted by one of the world’s largest medical imaging companies to help it solve a critical filament winding problem: manufacturing MRI magnetic coil cases. Each MRI device contains several of these cases produced using a process called wet resin filament winding. In a continuous winding process, the resin is wound around large mandrels then shaped using gigantic lathes after a curing step.

Inconsistent temperatures and viscosities led to many unusable parts.

A lot can go wrong with the seemingly simple process of filament winding. A two-axis machine automatically wet winds the fiberglass strands around a mandrel after the strands are dragged through a resin bath. The MRI manufacturer used a decade-old machine to build the coil cases, making it challenging to find and buy spare parts if the system broke down.

More so, the equipment was simply incapable of maintaining consistent temperatures, viscosity, and ratios, which rendered many finished cores unusable. The fiberglass cores would be ruined if the batch temperatures were off by fractions of degrees or the material slightly off-ratio. In order to complete the cores, they had to be cured for over 12 hours in an industrial oven, meaning operators wouldn’t know if they had a usable part until the end of that period— a highly inefficient process. Another challenge was the resin mix needed constant agitation because it contained solids.

Graco’s HFR Meter, Mix & Dispense System paired with MD2 Two-Component Dispense Valve.

When Air Power’s technical specialist Neal Cutler analyzed the manufacturer’s production line, he noticed the temperature was always inconsistent from area to area. Neal said the system could only maintain consistent temperatures while the material was dispensed. With his background in advanced fluids, he felt a newer Graco Hydraulic Fixed Ratio (HFR) Meter, Mix & Dispense System (see Image 1) with automated features could address their problems.

As a result of close collaboration with Graco’s Sealants & Adhesives team, Graco engineers diligently worked to add new functionality to the HFR’s control panel that would automate material circulation between dispenses. “So now, the material constantly moves through the system, and we're able to maintain good control over what’s dispensed.”

Air Power tested the new Graco configuration of the HFR Meter, Mix & Dispense System and MD2 Two-Component Dispense Valve in its lab to ensure it would run successfully in a wide range of circumstances. After some fine-tuning and minor adjustments, the MRI manufacturer gave Air Power the green light to install Graco's solution at the facility.

The new dispensing system is more accurate and can deliver precise ratios and volumes every time. Additionally, precision dispensing saves material waste, reducing scrap and rework—­­­­­­­­­­­­­ a significant issue the MRI manufacturer was experiencing. Plus, easier maintenance with standard parts eliminates costly pump rebuilds and the need for backup pumps.

When paired with Graco’s MD2 Two-Component Mixing Dispense Valve (see Image 2), the manufacturer would also increase productivity through more dispensing time. The simply designed valve has few moving parts and it’s easy to maintain. At the same time, the valve can easily handle this manufacturer’s two-component resin mix — keeping it on ratio plus or minus 1% automatically, with very little human intervention. A single operator can control all processes using the system’s advanced display module (ADM).

Since the initial installation of Graco's solution at this Global MRI Manufacturer's facility, Air Power has received orders for five additional systems. Those new Graco systems are now in various stages of installation at factories around the world.