Case Study: Shelving Label Holder

We received a web inquiry a while back for a custom plastic label holder for stockroom shelving in a fast-food environment. They were currently made of blue butyrate.

We called them up, learned they were just down the street, and paid them a visit.

We asked them what was going on, and they told us they had an existing supplier who could make them 50,000 parts per year, but their prices were going up. We reviewed the part, learned that these were actually made out of an extrusion and then had a secondary operation to cut out notches. This was a very labor intensive process.

We said we could use injection molding for it, and they asked what it would look like. Would it be the same material? Same color? Same finish?

Our calculations showed that a 2 cavity mold would halve their piece price back to what they were initially paying for the labels. Because the notch was molded in, there would be no additional labor costs allowing the piece price to remain relatively stable.

We couldn’t find a supplier to supply butyrate resin, and our research showed that butyrate is only for extrusion molding. Lucky for us, butyrate was not a requirement. So we reverse engineered the part and 3D printed the label out of polypropylene and ABS. The polypropylene print looked rough, but showed flexibility. The ABS was stiff as a board, but showed off the molding quality.

The customer liked what they saw from the prints and gave us a PO. After building the tooling, we ran different materials for the customer to get the feel similar to the extruded ones. We settled on Nylon 6 and the color matched the parts. However, after molding there were visible stress marks when the label was put on the shelf (it had to bend around a vertical wire).

After experimenting with different materials using an off the shelf colorant, the customer actually preferred the off the shelf colorant. Then found a material, ABS, that took the color well and showed no visible stress marks while maintaining flexibility.