The selection basis and key parameters of the knife plate spring pad
The selection of the die-cutting plate spring pad is directly related to the quality of die-cutting products and production efficiency. It is necessary to comprehensively consider multiple factors such as the characteristics of the die-cutting base material, die-cutting plate parameters, and die-cutting process requirements. The following key parameters and selection basis should be focused on.
Material is the fundamental prerequisite for selection. Currently, the mainstream material for knife plate spring pads in the market is polyurethane. Compared with ordinary rubber, it has better wear resistance, elastic recovery rate and aging resistance, and is suitable for most die-cutting scenarios. For scenarios where extremely high die-cutting accuracy is required and the base material is relatively thin, high-hardness polyurethane spring pads can be selected to ensure the stability of positioning and compaction. For scenarios where the base material is thicker and the die-cutting resistance is greater, soft polyurethane or rubber elastic pads with better elasticity can be selected to enhance the buffering and unloading effect. In addition, in special environments (such as high-temperature die-cutting), modified polyurethane materials with high-temperature resistance properties should also be selected.
Hardness is the core parameter that determines the adaptability of elastic pads. It is usually measured by Shore hardness (A), and the range is mostly between 30A and 90A. The hardness selection should match the thickness and hardness of the base material: When die-cutting soft base materials such as thin paper and film, it is advisable to choose a medium soft elastic pad of 40A-60A to avoid damaging the base material due to excessive hardness and high pressure. When die-cutting hard or thick substrates such as cardboard and corrugated paper, 70A-90A hard elastic pads should be selected to ensure sufficient compaction force and buffering effect. At the same time, the hardness also needs to match the Angle of the cutting edge of the knife plate. The smaller the Angle of the cutting edge, the less hard the elastic pad is recommended to be used to reduce the wear of the cutting edge.
The thickness and width parameters need to match the size of the knife plate. The thickness is generally between 1mm and 10mm and needs to be adjusted according to the height of the die-cutting plate and the die-cutting pressure. When the height of the die-cutting plate is relatively high, a thicker elastic pad can be selected to increase the buffer stroke. When the die-cutting pressure is relatively high, appropriately increasing the thickness can enhance the buffering effect. The width needs to match the width of the blade, usually 2mm to 5mm wider than the blade to ensure full coverage on both sides of the blade, achieving uniform compaction and buffering. In addition, parameters such as the density and tensile strength of the elastic pads also need to be taken into account. High-density elastic pads are suitable for high-precision die-cutting, while those with high tensile strength are more appropriate for high-frequency die-cutting scenarios.