Stackable, Flipping Ultrasonic Cleaning Baskets for Sterile Bottles

March 12, 2019 | Custom Wire Baskets, Stainless Steel Baskets, Parts Washing

Medicine Bottles with Blue LiquidCleaning bottles can be a challenge for an ultrasonic cleaning process. To get the best results, the cleaning fluid needs to get in the bottle, which means holding the bottle open side up. However, to dry the bottles, they need to be flipped upside down after the wash cycle is complete. Doing this manually, one bottle at a time, is slow and inefficient (and puts the bottles at greater risk of breaking).

So, when a major manufacturer approached Marlin to create a solution for cleaning their glass medicine bottles and lids for a multistep parts-cleaning and sterilization process, Marlin’s engineers had a big task in front of them.

Saving Time by Flipping the Entire Ultrasonic Cleaning Basket

During the client’s seven-step parts cleaning process, the bottles would be:

  1. Dipped in the ultrasonic cleaning machine’s wash tank;
  2. Rotated during removal to pour out excess cleaning fluid;
  3. Air-dried upside down on a drying rack;
  4. Rotated upright again for a final rinse;
  5. Rotated upside down a second time;
  6. Inserted into a depyrogenation oven (to remove contaminants that could cause fevers) at 509˚F (265˚C);
  7. Stored in stacks while upside-down to save space and prevent particulates from entering the bottles/caps while they wait for bagging.

If each bottle had to be flipped manually for this process, it would greatly extend the process’ duration and the risk of a bottle being mishandled and dropped. So, Marlin’s engineers needed to make a custom wire basket that would be easy to grab and flip without removing any of the individual bottles. To do this, the basket needed:

  • Easy-to-Grab Handles That Don’t Protrude Beyond the Frame. Handles can make it much easier to hold onto baskets, but large wires extending above the basket would keep it from being easy to store while flipped. To address this, large cutout handles were installed into the sides of the basket.
  • A Secure Lid. To keep bottles from falling out, a large, secure wire mesh lid was added to the basket. There were two ideas for this lid from the design team: a hinged lid with a set of latches at the front, or a lid with no hinges and four latches. The first design would be quicker to open and close, and would prevent lid loss. The second design would be easier to move out of the way of the bottles during loading and unloading.
  • Strong Dividers to Hold Each Bottle in Place. During the process of flipping the ultrasonic parts cleaning basket upside-down, the bottles would be at great risk of sliding around and impacting one another or even of falling over in the basket. To eliminate this risk, a set of dividers was added to hold each bottle in place and prevent part-to-part contact that could have damaged the bottles.
  • Nesting Design for Basket Tops and Bottoms. To ensure ease of stacking in the ultrasonic wash tank and on the factory floor, Marlin’s engineers needed to create design elements for the lids and the bottoms of each basket that would make them nest neatly when stacked either upside-down or right-side up. A set of small notches and bars would help facilitate this with ease.

A coating material was considered to help prevent the glass bottles from cracking when they would be flipped. However, the oven-like temperatures of the depyrogenation process would not have been good for many soft coating materials. Instead, it was determined that keeping the dividers tight so the glass bottles couldn’t shake in place too much would be the better solution.

Medical-grade stainless steel was used for the frames of the baskets to help ensure sterility and long-term durability. The electropolished stainless steel would prevent microbes from settling on the surface of the basket—making it easy to sterilize in the same washing processes that the parts were subject to.

A second set of baskets was devised for the lids and liners that the bottles would use. These baskets would use the same design elements—just with different dimensions to accommodate the smaller parts.

Delivering Quality Custom Ultrasonic Cleaning Baskets, Engineered Quick

Marlin’s engineering team, once they had settled on the basic basket design, passed it through a finite element analysis (FEA) software program to verify that the design would meet the client’s needs.

Each time the basket failed the test, a report was generated showing why it failed so the design team could correct the issue before trying again. It wasn’t until the ultrasonic cleaning baskets were able to pass this test that the design would be passed along to the manufacturing team.

To ensure the consistency needed to make the baskets uniformly stackable and of high quality, the manufacturing team used wire-bending robots, automated welders, and other pieces of factory automation to handle the assembly of each basket. Thanks to the precision of automation, Marlin’s production team was able to meet millimeter-tight parts tolerances with ease—creating baskets that could be used without worry whether they would mesh properly.

In the end, Marlin was able to meet the client’s custom wire basket needs in just two weeks, creating dozens of stainless steel wire baskets and shipping them in time to prevent delays for the client.

Need a custom ultrasonic parts cleaning basket right away? Reach out to the masters of delivering Quality, Engineered Quick® at Marlin Steel!

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