[Heat transfer film] Silk screen printing process for shoe and apparel labels

[Heat transfer film] The production process of heat transfer films for shoe labels includes the following steps, with explanations based on characteristics of different transfer films (e.g., TPU, PET substrates): 

1. Substrate & coating preparation 

- Substrate selection: PET or TPU films are commonly used as carriers, requiring high temperature resistance (140–180℃) and low tensile deformation. 

- Release layer coating: Release agent (e.g., silicone oil coating) is applied on the substrate surface to ensure smooth peeling at high temperatures. 

- Printing layer preparation: Patterns are multi-layer printed on the release layer via screen printing, with resolution up to 300dpi for clarity. 

2. Adhesive layer treatment 

- Adhesive screen printing: Hot-melt adhesive (e.g., TPU adhesive) is screen-printed on the back of the printing layer; formulation is adjusted per shoe materials (leather, synthetic leather, etc.) to ensure bonding strength. 

- Drying & curing: The adhesive layer is dried or UV-cured to prevent sticking. 

3. Slitting 

- Slitting process: Cut into rolls or sheets per shoe label sizes; edges are edge-wrapped to enhance durability. 

4. Performance testing 

- Peel force test: Verifies bonding strength between transfer film and shoe materials. 

- Weather resistance test: Tests pattern durability under high temperature, friction, etc. 

5. Storage & packaging 

- Moisture/heat protection: Finished products are stored upright in a cool environment to avoid high-temperature deformation. 

- Rolled/flat packaging: Packaged per customer requirements, with applicable temperature range marked (e.g., 140–165℃). 

Key process parameters 

- Temperature control: Hot-pressing temperature adjusted by shoe materials (120–140℃ for leather, 80–100℃ for fabric). 

- Pressure & time: Typically 4–6 kg/cm² pressure, 10–15 seconds. 

Application examples 

- Leather shoe labels: High-viscosity TPU adhesive film used, hot-pressed at 140℃. 

- Mesh shoe labels: Low-melting-point adhesive film (80℃) for dot bonding to avoid affecting breathability. 

This process adapts to diverse shoe material requirements and achieves firm pattern transfer by optimizing substrates, adhesives, and hot-stamping parameters.