Hot Stamping Foil Features and Key Points Analysis II

2. Color foil

Color foil, also called powder foil, is a kind of hot stamping material made by coating pigments, resin adhesives and other solvents on the film base. Hot foil stamping can be used to create a variety of color graphics.

The development and production of colored foils is later than that of electro-aluminum foils, and is mainly used instead of traditional color chips. Its characteristics are: a variety of colors, a wide range of options, can be used for automatic continuous hot stamping process, less waste, easy transport and storage. The foil package is the same as the electro-aluminum foil and is a very popular pigment foil. However, because the color layer of the color foil is thinner, compared with the color film, the color of the color film is not as bright, thick and full.

1 color foil composition.

The composition of the color foil is similar to that of the electro-aluminum foil, except that the electro-aluminum foil is vacuum-deposited with a layer of metallic aluminum, and the color foil is directly coated on the base film and is not plated with aluminum. The color foil consists of three or four layers.

Three-layer color foil production method:

The first layer is a base film layer. The base film is generally a 12 to 16 μm thick polyester film. It mainly acts as a supporting coating. Its packaging form is a reel type, which facilitates continuous processing, storage and transportation.

The second layer is a release layer. The coating of the release layer is a silicone resin or a wax liquid, and its function is to make the color-adhesive layer quickly detach from the base film and adhere to the material to be heated during hot stamping. Detachment layer must have a good shedding effect, otherwise it will cause hot stamping color, uneven, and other quality problems.

The third layer is a color layer. The color-adhesive layer is mainly composed of a pigment, and then a binder, an alcohol solvent, and other fillers are added and mixed in a certain proportion. The various colors of the colored foil are mainly dependent on the coating and formulation of this layer. Commonly used red, yellow, green, black, etc., are made according to user requirements and coated. Due to the addition of adhesive, it can be hot pressed by hot stamping to firmly bond it to the object to be heated.

The four-layer color foil separates the color-adhesive layer, and its purpose is to overcome the defect of the insufficient adhesion material in the color-adhesive layer to ensure the hot stamp adhesion.

2 color foil performance and hot stamping.

Due to the differences in the production process, batch, etc., the color foil must be well-understood in performance and use. The color foil is classified by a base film, including a polyester film and a paper film; it is classified into a color-adhesive layer binder and is divided into a water-soluble foil and an alcohol-soluble foil. Some foils are suitable for hot stamping large area patterns, while others are suitable for small area graphics and foils with patterned patterns, so they must be selected according to need.

A. The performance of colored foils. The properties of the colored foil are determined by the nature of the polymer selected. In the hot stamping process, it must have good detachment, adhesion, and can accurately display a variety of colors. When making colored foils, it must be accurately understood that the thickness of the coating is uniform, typically 0.05 mm. In addition, the color material in the color-adhesive layer must be mixed with the binder to be coated.

B. Hot foil stamping. The color foil foil stamping is more difficult than the electro-aluminum foil, especially if there is a large color difference with the surface of the workpiece to be ironed. If the material is improperly selected or is not well-handed, there will be quality problems such as missing bottom, pattern, discoloration, and stencil. Therefore, according to the texture, form, pattern depth, and thickness of the mesh, the pressure, time, and temperature are properly grasped during hot stamping, so that the image after hot stamping can be clear, plump, and bright. Firmly does not fall off.

(to be continued)