Factors to Consider
WHY CHOOSE ROTARY DIE CUTTING
In deciding which die cutting method to use in producing a part for any given application, there are many factors to be considered. You will need to answer the following questions, at a minimum:
- What is the material to be cut?
- Is the material difficult to handle?
- How complex is the part?
- What equipment and tooling will be required?
- What is the overall cost to produce to part?
- What is the required production volume?
- What is the customer’s delivery timing?
In many cases the material has been specified by the customer and chosen based on the specific application of the finished product. Most common materials have already been proven to be effectively cut using various methods, and the advantages or challenges of one method vs. another for a given material may be well known. In the absence of prior knowledge, materials must be evaluated based on relative difficulty of being cut cleanly with the various processing methods. Materials that are routinely produced in roll form are often candidates for rotary die cutting, but often the material consists of a complex lamination of several material layers, including a base material, adhesives, liners, or others. It is crucial to understand how an intricate construction will react to rotary die cutting, especially if the finished part requires cutting through specific layers while avoiding cutting through others. Materials that are easily torn or damaged may require an additional carrier layer to support the fragile material during processing. Materials such as a fibrous felt or metallic foil will present specific challenges that will drive the design of rotary tooling to achieve a satisfactory cut. If waste material – either internal slugs or external web matrix – is to be removed during processing, the cutting method should be evaluated to confirm the possibility of effective waste removal.
Ultimately, any material, whether simple or complex, should be evaluated by an experienced rotary die manufacturer to assure it can be efficiently and consistently cut using a rotary method.
Another important consideration is the processing cost, including equipment, tooling, and labor. The evaluation will vary depending on whether an investment in rotary press equipment has already been made, or if justification is being sought to purchase capital equipment for a new project. If rotary die-cutting is a current capability, each project should be evaluated based on the cost of part-specific tooling, required production volume, labor, and delivery timing. These criteria will each have an effect on the cost of the project.
When deciding whether to invest in rotary die cutting capital equipment for the first time, careful consideration of several factors is required, including capital spending budgets and alignment with high level company strategy to pursue similar projects and markets for the long term.
Production volume is a key consideration in deciding whether to utilize rotary die cutting. While initial investment in rotary die tooling is typically higher than flat steel rule die tooling, overall cost is often significantly lower when spread over higher part volumes. In general, higher volumes will justify investment in rotary tooling, as rotary die cutting takes advantage of the potential efficiency of higher production speeds and lower labor requirements per part. However, it is important to consider the actual quantities you will produce in each production run based on customer requirements. In other words, an annual volume of 100,000 pieces could represent a very different cost picture depending upon whether you produce in batches of 1,000 (100 runs per year) or 20,000 (five runs per year). Batch size will be determined by your equipment capacity and utilization for other jobs, as well as specific customer delivery requirements.
For many applications, part complexity will determine the best die cutting method. Rotary die cutting is favored in cases where multiple cutting steps are required to produce the finished part. Part complexity increases with each added material layer, cut pattern, and cutting depth. Sophisticated multi-station rotary presses allow all such die cutting steps to occur in sequence so that manual handling of parts between steps is eliminated. Advanced rotary presses have the capability to control important parameters such as web tension, cutting pressures, and speed. There are several types of possible cutting actions, including shape cutting, sheeting, scoring, slitting, or perforating. Rotary die cutting is often chosen when a combination of these actions is required for a single part.
Benefits of Rotary Die Cutting
- Uniform, repeatable, precision cuts
Reduced material waste
Labor reduction (automated process)
Suitable for high volume production
Rapid turnaround time