The application scenarios of knife plate spring pads in the printing and packaging field

The application of die-cutting plate spring pads is highly concentrated in the printing and packaging industry. Its core value lies in achieving a tight fit between the die-cutting plate and the substrate through elastic compensation, reducing die-cutting defects. Different die-cutting processes and substrate types have significant differences in the performance requirements for spring pads, forming a scenario-based application logic.

In the corrugated box die-cutting scenario, the core requirements for the knife plate spring pad are "impact resistance and high buffering". The corrugated paper base material is thick (3-12mm) and has hollow layers in its structure. During die-cutting, the force on the knife plate is uneven, which can easily lead to problems such as "line breakage" and "missed cutting". At this point, a natural rubber pad with a Shore of 40-50 degrees should be selected. Its elasticity can buffer the downward pressure of the knife plate, allowing the cutting edge to smoothly cut into the peaks and valleys of the corrugated paper, while also preventing the knife plate from chipping due to excessive local force. On the express delivery carton production line, such elastic pads, when combined with fully automatic die-cutting machines, can achieve high-speed die-cutting of 150 to 200 sheets per minute, and the service life of a single elastic pad can reach 80,000 to 120,000 times.

In the scenarios of precision die-cutting of color boxes and cigarette packs, "high precision and low deformation" have become the core demands. The base materials of color boxes are mostly coated paper and card paper. After die-cutting, it is necessary to ensure that the cut is smooth and the indentation is clear. Moreover, it often involves composite processes such as hot stamping and lamination, which have extremely high requirements for the flatness of the spring pads. At this time, polyurethane precision spring pads with a Shore of 50-60 degrees are usually selected. Their uniform foaming structure can ensure that the pressure compensation at each point of the knife plate is consistent, avoiding the problems of "burrs" and "uneven indentation depth" caused by the deformation of the spring pads. In the production of cigarette packs, this type of elastic pad is compatible with rotary die-cutting machines and can achieve a die-cutting accuracy of 0.02mm, meeting the strict appearance requirements of cigarette packs.

In the scenarios of label and self-adhesive die-cutting, the elastic pads need to be adapted to the characteristics of "thin substrate and high frequency". The thickness of the label base material is only 0.05-0.2mm. During die-cutting, problems such as "sticking to the knife" and "tearing the edge" are prone to occur. Therefore, Shore 30-40 degree silicone elastic pads are mostly selected. Their soft properties can assist in the separation of the label from the knife plate, and at the same time, the elastic recovery rate remains stable under high-frequency die-cutting. In the self-adhesive label production line, silicone elastic pads, in combination with rotary die-cutting machines, can achieve a die-cutting speed of over 300 meters per minute, and can be adapted to various surface treatments of label substrates such as lamination and varnish coating.