1. Precautions for Hot Peeling the Transparent Film Layer on Printer Film Rolls

1.1 Incomplete Curing of the Printer Powder Adhesive Layer Leading to Pattern Detachment

The bonding mechanism of DTF film relies on a thermosetting adhesive powder that is coated onto the film surface and partially cured during baking. Its final adhesion strength is achieved through secondary melting and curing under the high temperature and pressure of the heat press.
During this heat-pressing stage, the adhesive layer is in a molten, flowable state and must cool down to solidify completely. Only after cooling does it transition from a liquid-like state to a fully cured solid, forming stable intermolecular forces that tightly bond to the substrate surface or fibers.

If the film is peeled off immediately (hot peel), the adhesive has not yet fully cured and remains in a semi-molten, viscous state. Peeling at this stage can forcibly separate the adhesive and ink from the substrate, causing incomplete transfer, missing sections, edge lifting, or breakage of fine text and thin lines. In severe cases, the entire graphic may be pulled off the substrate.

1.2 Unstable Bonding Between Ink and Substrate, Leading to Layer Separation

A completed DTF transfer requires a stable three-layer bonding structure consisting of Ink → Adhesive Layer → Substrate.
During heat pressing, the elevated temperature increases molecular activity, allowing ink molecules and adhesive molecules to interpenetrate and begin forming a unified interface. However, this structure only stabilizes during the cooling phase as molecular movement slows and physical adsorption plus chemical bonding reach equilibrium.

If the film is peeled too early, the ink–adhesive bond has not fully stabilized, and the frictional adhesion between the adhesive layer and the substrate is still weakened due to high temperature. As a result, the peeling force may Separate the ink from the adhesive (causing patchiness, ink loss, or exposed substrate), or Separate the adhesive from the substrate (causing the entire graphic to lift or float).

1.3 Substrate Expansion Not Recovered, Causing Deformation When Peeling

Most substrates—such as cotton or polyester fabrics—expand slightly under the high temperature of the heat press as fiber gaps widen. They gradually contract back to their original state during cooling.
If the film is peeled immediately after heat pressing, the substrate is still in an expanded state with enlarged fiber gaps. The adhesive layer has not yet fully penetrated and anchored into these gaps.

Peeling at this moment applies tension to the soft, expanded substrate, potentially causing Local deformation of the fabric，Edge lifting of the graphic (especially near seams or warped areas)，Once cooled, the substrate contracts back to its stable form, and the adhesive layer becomes mechanically locked into the fiber gaps — creating a strong “mechanical interlock” structure. Peeling at this stage avoids adhesion failure caused by substrate deformation.

2. Precautions for Removing the Film Layer

It is recommended to remove the transparent film layer approximately 10 seconds after heat pressing. This allows the adhesive layer bonded to the substrate to fully solidify before the peeling operation. Once the adhesive temperature on the substrate drops below 212℉ (100℃), the transparent protective film can be safely removed. At this temperature, peeling the film will not significantly affect or damage the underlying printed image.