Performance Parameters of knife plate spring Pads and Indentation Strips - Understanding the "Core Code" of Selection
During the selection process of ejection rubber and indentation strips, many purchasers and producers often get confused in the face of complex product parameters. In fact, behind these parameters lies the "core code" that suits different production needs. Only by accurately interpreting key indicators such as hardness, resilience, material, and size can the most suitable accessories for one's own production line be selected, achieving a dual improvement in die-cutting and creasing quality and efficiency.
The core parameters of the knife plate spring pad are concentrated in two major dimensions: "elastic performance" and "durability". Hardness is the primary consideration index, usually expressed as Shore hardness (A). Elastic pads of different hardness levels are suitable for different die-cutting scenarios: Elastic pads with a Shore hardness of 30-40A are relatively soft in texture and are suitable for die-cutting materials that are prone to deformation, such as thin paper and cardstock, effectively preventing paper crushing. The elastic pad with a Shore hardness of 50-60A has a moderate hardness and is a universal choice, which can meet the die-cutting requirements of most packaging cardboard. Elastic pads with a Shore hardness of over 70A are relatively hard in texture and are suitable for die-cutting thick materials such as corrugated cardboard, providing stronger support. The resilience determines the service life of the spring pad. High-quality spring pads can quickly return to their original shape after multiple compressions. The resilience usually needs to reach over 80%. If the resilience is insufficient, it will cause the spring pad to age rapidly and increase the frequency of replacement. In addition, temperature resistance is also an important parameter. The frictional heat generated during die-cutting may cause the elastic pad to soften. Therefore, the elastic pad used for high-speed die-cutting needs to have a temperature resistance of over 100℃.
The parameter selection of the creasing matrix is centered around "shaping effect" and "compatibility". Height is the most crucial dimensional parameter for creasing strips and should be precisely matched according to the thickness of the paper. Taking the common production of folding cartons as an example, when the paper thickness is 200-300g, creasing strips with a height of 1.5-2.0mm should be selected. When the paper thickness is 300-500g, the height of the creasing strip needs to be increased to 2.0-2.5mm. If the height of the indentation strip is insufficient, it will cause the crease to be blurred. If the height is too high, it is easy to cause paper cracking. The width parameter is related to the clarity of the crease. Generally, the width of the crease strip should be 0.5 to 1mm larger than the thickness of the paper to ensure that the crease is evenly stressed. In terms of material, high-density polyethylene creasing strips have strong wear resistance and are suitable for mass production. Rubber creasing strips have good elasticity and are suitable for curved or irregular-shaped creasing scenarios. The selection of different materials should be based on the production batch and product shape requirements.
In addition to the consideration of a single parameter, the parameter matching between the spring pad of the knife plate and the indentation strip is also of vital importance. For instance, in the die-cutting and creasing of thick corrugated cardboard, high-hardness knife plate spring pads and high-height creasing strips should be selected in combination to balance the die-cutting pressure and creasing depth. In the production of thin paper color boxes, a combination of low-hardness elastic pads and low-height creasing strips is required to prevent paper damage. Only by understanding these parameter "codes" can we get out of the predicament of blind selection and enable the knife plate spring pad and indentation strip to truly play a role in enhancing product quality.