Before the Box
Packagers and converters understand the "moment of truth," when a text or graphic element found on a product's packaging helps prod a consumer to make a purchase. When it comes to folding cartons, it could also be a uniquely shaped box, a strategically positioned foil stamp, or an attractive varnish.
Making these decisions—mostly subliminally—consumers don't consider where the carton came from or why it looks the way it does. Yet before it was a box on a shelf, a series of intricate steps turned what was once a sheet or roll of paperboard into a finished product.
The starting line
Like most packaging jobs, creating a folding carton requires strong communication between the equipment supplier and the converter. Ulrich Kretzschmar, a product and business development manager for RotoMetrics, says there needs to be an understanding of exactly what the customer wants to produce. It is vital for both parties to agree on the type of paperboard being used and the project's expected run length, because each impact the life of the die used for the carton. This, says Kretzschmar, helps determine which type of die the customer should use.
When working with RotoMetrics, for instance, the converter provides a sample or profile of the carton and the die layout. RotoMetrics makes rotary dies, so the next step is deciding whether a solid rotary or a flexible die should be used. Depending on the application and type of press, other suppliers might require a steel rule die.
On rotary systems, solid dies are generally best for cutting thicker paperboard while flexible dies are better for thinner substrates and shorter runs.
"Flexible tools are also an efficient way to deal with shorter run lengths, especially with respect to changeover times and lower tooling costs, while still offering a reasonable die life," Kretzschmar explains.