By Darryl Carlson and Joe Carrillo, Royal Paper Box
Would you know the right questions to ask if one of your production departments was struggling to do their job? As executives and managers at folding carton companies, we can always learn more about what’s happening on the shop floor. Throughout the year, PPC plans to present a series of blogs to help you get a bit smarter about various aspects of carton converting. Royal is kicking things off with die-cutting. So, here’s what you should know to keep your cutting department sharp and efficient.
What must be done right?
In actuality, cutting is the easy part. It’s the processes that happen before and after cutting that really make or break carton quality and production efficiency. For example, the first major area that comes to mind is layout. Blanks must be laid out on the sheet correctly. An incorrect layout can affect cutting, blanking, stamping, finishing—a whole variety of steps down the line. When cartons are layed out correctly, it allows the operator to maximize run speeds. A good production run starts with a good layout.
Pre-makeready and makeready
If your machinery isn’t running, you’re losing money. The key to keeping die-cutting presses running is to master the makeready. Here’s how the process should work: the pre-makeready team builds all the tooling, die boards, blankers, and strippers, and puts everything on a cart to be ready when the current job on press is done. That way, the press operator can remove the old tooling, put in the new tooling, and get the next job started right away. The goal is to have pre-makeready done so that makeready on press is as fast as possible. It’s all about planning and timing.
Blanking is the final stage of the cutting process. Blanking strips waste and stacks the blanks, preparing them for folding and gluing and bypassing manual stripping. It’s a critical step—and a challenging one for most converters. Some of the challenges include high slip coating and small variances in distribution of cutting rules or embellishments that cause cartons to stack unevenly. Slick coatings can cause the blanks to start sliding around, making them very difficult to stack. Blanks with silk screening or other embellishments that raise only one area of the design can also give you stacking troubles. When these issues become pronounced, you may find that going back to traditional air hammer stripping is more efficient.
What else could go wrong?
Here are a few things to consider. Printing many small cartons on a layout can cause the paper to stretch and therefore present challenges with trying to register die-cutting across the entire sheet. You may need to “chop” the die to make things fit or you can wait to build the die until you take some measurements from a printed sheet.
Also, be sure to consider the types of board, coatings, and other finishings involved in a job. For example, some coatings can lead to cracking once the board is cut and creased. You’ll also want to adjust your tooling for different types of board. Make sure your operators are well-versed in the advantages and pitfalls of various materials.
What’s on the horizon?
Better equipment and cleaner, faster cutting—that’s what. We don’t do a lot of small, intricate runs at Royal, but nonetheless we’re excited about the future of laser cutting technology. It’s allowing some of our PPC peers to do intricate work that can’t be done with traditional die-cutting tooling and techniques. Die-cutting presses are also getting faster. 10 years ago, the fastest die-cutting presses ran about 6,000 sheets per hour, and today they’re up to over 9,000 sheets per hour. We’re pretty efficient now, so we’re excited to see how the equipment of the future will make us better, and how cutting will change and evolve along the way.
Do you have tips or best practices around cutting? Share in the comments.