Enhancing Additive Manufacturing with Stainless Steel Baskets

July 4, 2017 | Stainless Steel Baskets, Marlin Steel Case Studies

3D printers work by assembling parts one layer at a time until the full part is complete.Additive manufacturing (a.k.a. 3D printing) has huge potential benefits for manufacturers of all sizes. 3D printed parts can be enormously complex in design, and many eliminate the need for any custom tooling altogether.

However, additive manufacturing brings a whole new set of challenges, as well. For example, some highly complicated shapes require the use of a special filler material to bridge gaps in the part until it is finished printing. When the part is finished, this filler has to be washed away so as to not interfere with the part later.

One manufacturer recently contacted Marlin Steel about creating a custom parts washing basket to hold 20 pounds of 3D printed parts, consisting of irregular shapes and sizes, through a 48-hour long wash cycle.

Ensuring Basket Durability

Although the chemical bath used in the client’s process was a relatively mild alkali detergent, the sheer length of the process posed a challenge for preventing basket corrosion. Even plain, pH-neutral water can cause oxidation in many metals after prolonged exposure—especially in a full-immersion application.

The baskets, and the parts they carry, were to be placed in a CleanStation XL Plus washing machine with a 25” x 37” x 25” stainless steel tank. Complete submersion of the parts and baskets was desirable to ensure the effectiveness of the bath at stripping the surface of the parts of any foreign material.

Because the wash cycle called for total submersion for so long, even in a mild chemical bath, the basket needed to have excellent corrosion resistance. This would call for either the use of a protective coating, or using extremely corrosion-resistant stainless steels, such as grade 304 or 316 SS.

Since one of the specified design features in the order was a hinged lid, coating was not considered the ideal solution—there would have to be bare spots at the hinges to ensure smooth movement, which would allow direct contact with the chemical bath. So, Marlin’s engineers recommended that the design incorporate a stainless steel alloy that could withstand days of constant submersion.

The load itself was relatively light—only 20 pounds—paired with the high tensile strength of the steel meant that the wires didn’t have to be excessively thick. A quarter-inch thick wire would be more than enough to support that weight.

Ensuring Process Efficiency

Stacking baskets can save space on the production floor, or even let multiple baskets fit in a wash tank at the same time.A 48-hour wash cycle is incredibly long, and to maximize throughput, the client needed to be able to put as many parts in the wash tank as possible without risking damage to their printed plastic components.

Eliminating empty space by packing parts close together would help get more parts in a basket, but increase risk of damage. Using set wires to hold parts exactly would allow close spacing without risk of part-to-part contact, but the 3D printed parts could vary in shape and size from one batch to the next, so a custom fit would be impractical.

Using dividers would provide a good compromise between part safety and capacity, allowing individual parts to be placed in separate chambers and limiting the risk of part-to-part abrasion during the two-day wash process. By making these dividers removable, the size of the spaces could be adjusted if necessary to accommodate larger parts.

Another measure taken to maximize the capacity of the wash tank was making it so that the baskets could be stacked during the wash process. By stacking baskets, the number of printed parts that could be washed at once doubles—an essential for such a long cleaning process.

Ensuring Ease of Use

The client’s manufacturing process relied on manual work to move and carry the baskets around the factory floor. To facilitate easy handling, two short handles were added to the exterior of the basket frame.

These handles would also make it easier for employees to stack the stainless steel baskets in the wash tank—keeping the top basket from slipping side to side over the bottom basket.

Verifying Basket Efficacy

To make sure that the baskets would be able to hold plastic 3D printed parts safely and survive the cleaning process, Marlin’s engineers used Autodesk physics simulation software to emulate the conditions of the process.

The simulation tracked the effects of the chemical bath on the stainless steel, the added weight of a fully-loaded basket on top of another, and numerous other environmental factors in the client’s manufacturing process. In mere minutes, the effects of years of continuous use could be simulated.

Any failures that occurred in the simulation were catalogued, along with the causes of the failure, so that the design could be refined until those failures no longer occurred. This process is repeated for every Marlin Steel basket design until the design can pass the test.

By keeping testing to a virtual environment, significant amounts of time and money can be saved on manufacturing and testing prototype baskets that would not work because of one small flaw that was overlooked in the design phase.

Marlin Steel specializes in creating custom steel wire baskets to meet a variety of production challenges. Working step-by-step to design and build the best possible basket, Marlin’s engineers combine constant learning with years of practical experience and advanced automation tools to solve manufacturing challenges for clients in all industries.

Learn more about how Marlin makes the ideal manufacturing baskets for processes like yours today!

Contact Marlin Steel