Electropolished Stainless Steel Basket for Washing Medical Cassettes

In Case Study, Stainless Steel Baskets

Marlin Steel on July 19, 2018

A stainless steel sheet metal basket for holding medical cassettes through a rigorous sterilization process.The term “cassette” isn’t one most people hear very often these days. To most people that remember them, cassettes evoke images of audiovisual playback devices. However, in the medical/pharmaceutical industry, medical cassettes have a completely different connotation. Rather than holding tape, medical cassettes hold medical tools or specimen samples for study.

Recently, a company in the medical research industry contacted Marlin Steel to request a set of custom stainless steel baskets for washing their medical cassettes. These cassettes needed to be absolutely sterile because they would be used to hold samples of skin, cancer cells, proteins, treatment cells, and other specimens for study in cleanroom environments. Any dust/dirt particles or leftover material from previously-held specimens could significantly alter the properties of the next set of specimens for study (impacting the reproducibility of medical tests), so these contaminants had to be completely eliminated.

Because of this, the parts washing process for the medical cassettes had to be especially harsh—using strong disinfectant chemical cleaners, rough agitation, and high temperatures to achieve sterility. Additionally, the cassettes needed to be able to dry completely in a clean environment.

So, the custom stainless steel parts washing basket that Marlin would make for this client would have to:

  • Withstand high temperatures;
  • Allow held parts to dry efficiently;
  • Make it easy for held parts to be accessed for washing;
  • Prevent debris and runoff from the cleaning process from sticking to the basket;
  • Keep held parts in place through rough agitation; and
  • Be resistant to harsh chemicals.

Meeting Sterilization Process Requirements with a Sheet Metal Basket

In most cases, when Marlin Steel makes a parts washing basket, the basket is made primarily out of stainless steel wires instead of sheet metal—sheet metal parts may be used for the outside frame, but the contact surfaces are usually rounded steel wires. This helps to prevent debris or runoff created during the washing process from sticking to the basket and contaminating parts.

However, in this particular medical parts washing application, it was determined that laser-cut and CNC punched/shaped sheet metal would be the best option for the client’s needs. Sheet metal has a much higher tensile strength than steel wire and requires fewer welding operations to ensure a strong basket. This added durability was needed because of how rough the client’s specific sterilization process would be—rough agitation would be a key part of the process, and a lightweight wire basket could have been damaged after only a few wash cycles. So, thicker stainless steel sheet metal was used instead.

To help keep the medical cassettes in the basket through rough motion, a heavy steel lid was added to the basket’s design. This lid could keep the cassettes secure through the rough washing process, helping prevent mishaps with free-floating medical parts in the washing equipment. The lid was given four large openings to make it easy for a gloved hand to grip and remove it when necessary.

Large folding handles were added to the basket for ease of carrying from the wash process to the cleanroom. When in the wash process, the handles would collapse to minimize the size of the basket.

To keep the medical cassettes organized in the basket, dividers and custom-shaped inserts were added to the design. These dividers would keep the specimen cassettes separated and held securely in place so they wouldn’t bounce around during the rougher motions used in the aqueous washing process.

Preventing runoff from sticking to the basket was a major challenge for the sheet metal basket. The solution, aside from minimizing the width of the sheet metal plates and maximizing open space, was to electropolish the basket so its surface would be smooth on the microscopic level. By using electropolished stainless steel for the basket, Marlin’s engineers were able to minimize the risk of runoff or process debris sticking to it after the client’s cleaning and sanitation processes were completed. By using grade 304 stainless steel, Marlin’s engineering team could ensure that the basket would easily withstand both the chemicals and the high temperatures the client would use to sanitize their medical cassettes.

Building a Better Basket in the USA

Why did the client choose Marlin Steel instead of outsourcing the job overseas to some foreign company using cheaper labor? Because, they needed that “Made in the USA” precision that a company like Marlin Steel can provide. Each basket needed to be precisely engineered and manufactured to a consistent set of tolerances to ensure that the medical cassettes would fit inside.

They also needed to have the baskets shipped to them on a tight schedule—any delays in shipping would put them behind schedule for their own medical research. So, they approached an American company to ensure that they would get a precisely-engineered product quickly.

Marlin delivered Quality, Engineered Quick® by getting some process specifications from the client (things like process temperatures, chemicals, and specific equipment involved) so the engineering team could optimize the basket’s design to meet the client’s needs. Then, after completing the initial design, the engineering team ran it through a series of virtual physics simulations to verify that it could take the stresses involved to last for years of use. If the design failed the test, it would be reworked until it could survive years of use.

Once the design was finalized, Marlin’s manufacturing team started programming the robots at our OSHA award-winning Baltimore factory to get ready for assembly. Within hours, an assembly process was settled on that maximized productivity, quality, and safety for making the medical parts washing baskets. This setup, once completed, let the robots run with minimal assistance from the manufacturing team—letting the robots run for hours on end to complete all of the client’s baskets incredibly quickly.

Also, unlike manual laborers, the robots assembling the baskets don’t get bored or tired from making the same parts repeatedly. Combined with the precision of CNC machinery, this ensures that every part meets consistent parts tolerances.

When the baskets were completed, they were shipped straight from our U.S.-based factory to the client’s medical facilities for use. There were no delays for customs or other intermediaries that would be required for a product being shipped from another country.

Marlin’s combination of highly-trained and capable American employees, heavy investments in factory automation, and U.S.-based location allowed us to deliver “Made in America” quality for our client quickly.

Want to learn more about how you can get the perfect American-made custom basket for your manufacturing application? Contact the experts at Marlin Steel today! Or, check out our Stainless Steel Properties Sheet at the link below to learn about the different kinds of stainless steel that Marlin’s engineers work with:

Marlin Steel's Stainless Steel Properties Sheet

Author: Marlin Steel
Marlin Steel
Marlin Steel is a leading manufacturer of custom‐engineered products from steel wire and sheet metal. Its industrial material handling containers serve many industries including aerospace, defense, medical and automotive.

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