What is your level of understanding regarding the knowledge points of rotary die-cutting machines?

I believe most professionals in the die-cutting industry are familiar with flatbed die-cutting, but rotary die-cutting can also be a cost-saving alternative. However, rotary die-cutting is more challenging and requires significant changes in the process. 

Today, let's summarize and discuss the knowledge of rotary die-cutting machines, including equipment selection, daily operations, maintenance, and common problem-solving.

1. Equipment Selection for Rotary Die-Cutting Machines

When it comes to equipment selection, domestic production technology for rotary die-cutting machines is now mature and stable. Many companies can manufacture them, so there is no need to choose foreign products. When selecting the machine, pay attention to three key factors: working width, mechanical speed, and the number of workstations.

- Working Width:

The chosen working width should match the supporting equipment and products. The principle of rotary die-cutting is to cut the paper by pressing the upper rotary knife onto the lower roller. Therefore, the thickness of the rotary die-cutting knife needs to be appropriate. Too thin of a knife can cause deformation, while too thick of a knife increases manufacturing costs.

- Mechanical Speed:

A speed of 150-200m/min is generally recommended as the optimal economic speed. This speed minimizes tool and equipment wear.

- Workstation Selection:

In the past, three workstations (creasing, scoring, and die-cutting) were commonly used. However, nowadays, electronic die-cutting machines often have ten or more workstations.

2. Operation Guidelines for Rotary Die-Cutting Machines

There might still be some operators unfamiliar with the operation of rotary die-cutting machines. Here are some operational guidelines to follow:

- Pre-Startup Procedures:

Review the production schedule and construction requirements, check equipment running records, ensure no foreign objects on the machine, and conduct a thorough inspection and adjustment.

- Pre-Production Procedures:

Check for proper registration, make sure the die-cutting matches the box dimensions, install the die, create a base template with a thickness equal to the paper's thickness, adjust the die-cutting pressure, and ensure the positioning pins of the stripping unit are properly set.

- Production Guidelines:

Sample inspection during production, follow the construction requirements and approved samples, address material issues promptly, and perform comprehensive inspections and documentation after each die-cutting process.

- Post-Production Procedures:

Separate and label the qualified and defective products, fill out daily production reports and quality statistics, perform maintenance as per the maintenance schedule, stop the machine in the open die position after production, turn off the power, and fill out shift handover records.

3. Troubleshooting and Maintenance

To ensure the efficient operation of rotary die-cutting machines, proper training should be provided to operators and knife setters, and corresponding measures should be taken for common issues. 

- Gap Adjustment:

For rotary die-cutting machines, the gap between the upper blade and the lower roller is crucial. Understand the mechanical transmission and die-cutting principles. The gap should typically be between 0.003mm to 0.008mm. Adjust the gap by moving the axial-end rolls or using tapered rolling bearings.

- Regular Inspection:

Check the blade, waste stripping pins, and scrapers for wear during every shift. Address local wear by using spacer blocks.

- Observing and Record-Keeping:

Continuously observe the die-cutting process and keep accurate records. Immediately stop and inspect if any abnormalities are detected.

In addition, a comprehensive maintenance should be performed every two weeks, including lubrication and the replacement of vulnerable parts, to ensure the optimal working condition of the machine.

In summary, although rotary die-cutting machines have not been prevalent for a long time, they are increasingly in demand not only in the printing industry but also in various intelligent products' post-printing processes.