Key points for the coordinated adaptation of knife plate spring pads with different die-cutting equipment

There are differences in the types, structures and working principles of die-cutting equipment, and the requirements for the material, hardness and structure of the die-cutting plate spring pad also vary. The coordinated adaptation of the knife plate spring pad and the equipment is the key to ensuring die-cutting efficiency and improving product quality. At present, the mainstream die-cutting equipment is mainly divided into three types: flatbed die-cutting machines, rotary die-cutting machines, and rotary flatbed die-cutting machines. The key points for the adaptation of elastic pads for each type of equipment are as follows.

The flatbed die-cutting machine is currently the most widely used die-cutting equipment. It features high die-cutting pressure and high precision, and is suitable for high-precision die-cutting of various materials. Due to the planar contact between the die-cutting plate and the impression plate of the flatbed die-cutting machine, the pressure is concentrated at the moment of die-cutting, and the wear resistance and elastic stability of the spring pad are required to be relatively high. When adapting, polyurethane spring pads with moderate hardness (Shore A 60-80 degrees) and strong wear resistance should be selected to avoid rapid wear of the spring pads due to excessive pressure. For large-area die-cutting scenarios, block-shaped or strip-shaped combined spring pads can be selected to achieve uniform pressure transmission. For irregular-shaped die-cutting and fine creasing scenarios, it is necessary to select cast polyurethane spring pads with high dimensional accuracy and rapid rebound to ensure smooth die-cutting edges and clear creasing. In addition, the die-cutting speed of the flatbed die-cutting machine is relatively slow, and the deformation recovery time of the elastic pad is sufficient. Therefore, wear resistance and stability can be given priority, while elasticity should also be taken into account.

The rotary die-cutting machine features fast die-cutting speed and high efficiency. It is suitable for large-scale continuous die-cutting operations, such as production lines for corrugated boxes, labels and other products. The knife plate and the impression cylinder are in rolling contact. The spring pad needs to rotate synchronously with the cylinder, enduring periodic compression and rebound. Therefore, extremely high requirements are placed on the elastic recovery speed, wear resistance and fatigue resistance of the spring pad. When adapting, polyurethane elastic pads with high elastic recovery rate (≥90%) and strong fatigue resistance should be selected. The hardness should be controlled at 70-85 degrees on the Shore A scale to ensure no obvious permanent deformation under high-speed rolling and extrusion. Due to the centrifugal force existing during the rotation of the drum, the spring pads need to be fixed firmly. Ring-shaped or strip-shaped spring pads with fixed structures can be selected to prevent displacement and detachment during high-speed rotation. Meanwhile, the die-cutting temperature of the rotary die-cutting machine is relatively high, so polyurethane elastic pads with good heat resistance should be selected to prevent high-temperature aging and failure.

The rotary die-cutting machine combines the high precision of the flatbed die-cutting machine with the high efficiency of the rotary die-cutting machine, and is suitable for medium and small batch, high-precision die-cutting operations. The impression cylinder is circular, the knife plate is flat, and the spring pad is installed on the knife plate, bearing the dual forces of rolling extrusion and flat support. When adapting, a composite material elastic pad with both elasticity and rigidity should be selected. The surface layer should be made of polyurethane material with excellent elasticity, and the bottom layer should be a slightly more rigid support material to achieve uniform pressure transmission and stable support. The hardness of the elastic pad can be adjusted according to the processing material. When processing thin materials, Shore A 50-70 degrees is selected, and when processing thick materials, Shore A 70-80 degrees is selected. In addition, the die-cutting pressure distribution of the rotary flatbed die-cutting machine is uneven. It is necessary to increase the thickness of the elastic pads or select high-elasticity elastic pads in the pressure-concentrated areas such as the edge of the knife plate and the irregular parts to achieve pressure compensation and avoid local die-cutting not penetrating or excessive indentation.

No matter what kind of equipment it is adapted to, the material, hardness and structure of the spring pad should be precisely selected based on parameters such as die-cutting pressure, speed and temperature of the equipment, combined with the characteristics of the processed material. At the same time, regularly check the compatibility of the elastic pad with the equipment, and adjust or replace it in a timely manner according to the wear condition to ensure that the two work in coordination and improve the stability and efficiency of the die-cutting process.