Gold Stamping

The core principle behind the collaboration between foil stamping paper and a foil stamping machine is "thermal transfer by pressure." Simply put, the machine provides the necessary heat and pressure to precisely transfer the printed design from the foil onto the product surface. Below are the specific steps and mechanisms involved in this process:

1. Physical Installation and Alignment
Before operation, the foil must be properly aligned with the machine's conveying system. During setup, the foil is mounted on the unwind roll of the machine, ensuring its shiny side (the gold side) faces upward or toward the die. The stamping machine typically includes feed rollers, assist rollers, and rewind rollers. During the stamping process, the machine drives the foil intermittently or continuously through the system, feeding unused foil into the impression area while automatically rewinding the used foil.

2. Chemical Reaction in Thermal Transfer
Once the machine starts, the transfer of the design from the foil to the product surface occurs through the coordinated action of three key factors:

Temperature (Heating): Electric heating plates inside the machine heat the die to a specific temperature (typically between 80°C and 150°C). This high temperature melts the hot-melt adhesive layer on the foil, creating tackiness. At the same time, the release layer (release agent) in the middle of the foil loses adhesion when heated, allowing it to separate from the PET base film.

Pressure (Compression): The machine applies controlled pressure, pressing the die firmly against the foil. This pressure forces the melted adhesive to bond tightly with the substrate surface, while simultaneously causing the aluminum layer to fully detach from the base material.

Dwell Time: Within an extremely short period, the heat-sensitive adhesive securely bonds the colored image and aluminum layer onto the product surface.

3. Final Formation and Separation

After the die lifts and the pressure is released, the machine automatically advances the foil forward by a certain distance. At this point, the design originally adhered to the PET film has been successfully transferred onto the product, while the PET film—now waste foil—is collected by the machine. As a result, a clear, highly reflective metallic pattern remains on the product surface.

In practice, to achieve optimal results, the pressure applied by the machine must be adjusted according to the hardness and surface texture of the substrate. Additionally, the ideal temperature must be determined—the lowest possible temperature that still produces sharp, well-defined patterns—avoiding excessive heat, which could damage the foil or cause blurred lines.