Characteristic and Selection of Hot Stamping Foil Material

Hot stamping materials refer to the materials used in the press, fabrics, leather, coated surfaces, plastics and other cover materials, and are hot stamped on various graphic materials, and also include various hot stamping adhesion promoting materials. After melting adhesive materials by heating and pressing methods, various metal foils and the like are stamped on various articles to obtain ideal decorative processing methods, which have lasted for several centuries in China and are used on the cover of books. A hundred years of history. The earliest stamping materials used in China were single-sheet metal foils and powder sheets. Later, due to the development of the printing and splicing business and the continuous updating and improvement of the framing materials, hot stamping materials such as galvanized aluminum and colored foils appeared. These inexpensive new materials quickly replaced pure metal foil stamping materials.

Type of hot stamping material

1. Electrochemical aluminum foil

Electro-aluminum foil is a stamping material made by coating and vacuum evaporation with a layer of metal foil on the film base. Its packaging form is reel type. Electrochemical aluminum foil can replace metal foil as a decorative material, with gold and silver as the majority. It has the characteristics of gorgeous appearance, bright color, glittering eye-catching, easy to use, etc. It is suitable for hot stamping on paper, plastic, leather, fabric, coating material, organic glass and other materials. Electrochemical aluminum foil was transferred from Japan to China in the mid-1960s. Shanghai, Beijing, Fujian, and other places were put into production earlier. For more than 30 years, electro-aluminum foil has become a familiar material for frame mounting.

The composition of 1 electrified aluminum foil. The galvanized aluminum foil is coated with a release layer, a color layer, and a vacuum aluminum plated recoatable adhesive on a polyester film of 12, 16, 18, 20 μm thick, 500 to 1500 mm wide (a domestic film generally used 16 μm thick, 500 mm wide). The layer was finally made by rewinding the finished product. Domestic electro-aluminum foil is generally 4 to 5 layers.

The first layer of electro-aluminum foil is a base film layer. In China, 16 μm thick biaxially stretched polyester film is generally used; the main function is to support the coating adhered to it and to facilitate continuous operation during hot stamping. Base film layer in the hot stamping process can not be due to temperature rise and deformation, should have strong, tensile, high temperature and other properties.

The second layer of electro-aluminum foil is a release layer. It is generally coated with a silicone resin or the like. The main function is to make the color material, aluminum, and adhesive layer quickly detach from the polyester film after hot stamping (heating and pressurizing) and be transferred and bonded on the surface of the stamped object. Separation layer should have good separation performance, otherwise it will make the graphic after the stamping unclear, revealing flowers at the bottom and affecting the product quality of hot stamping.

Some galvanized aluminum foil products are not separated from the layer during production, and the color layer adhesive material with less adhesion to the base film or the appropriate amount of detached material is added in the color material so that the color layer can react color and play a detaching role. This is a four-layer structure of anodized aluminum.

The third layer of electro-aluminum is a color layer, and the main component is a synthetic resin and a dye that are suitable for film formation, heat resistance, and transparency. The main role of the color layer is two, one is to display the color; the second is to protect the aluminum plated image stamped on the surface of the article is not oxidized. The color of the galvanized aluminum foil can be orange, yellow, gray, red, green, etc. as required. The color of the color layer is given a luster through the aluminum plating layer, and the color has a certain change. For example, the color of yellow is gold after aluminizing, and the silver is gray after aluminizing. The requirement for the color layer coating is fine without any small particles, so as to avoid the occurrence of trachoma and damage the uniformity of the coating.

The fourth layer of electro-aluminum foil is an aluminized layer. The film coated with a colored layer, etc., is placed in a vacuum chamber in a continuous aluminum plating machine. Under a certain degree of vacuum, the aluminum wire is melted and continuously evaporated to the colored layer of the film by resistance heating to form an aluminum plating layer. The main role is to reflect light, change the color of the color layer, and make it shiny.

The fifth layer of galvanized aluminum foil is an adhesive layer. The adhesive layer is generally made of a fusible thermoplastic resin (whose type is more), coated on an aluminum layer by a coater, and dried to form an adhesive layer. The main function of the adhesive layer is to bond hot stamping material to the object being heated.

One of the reasons for the phenomenon of non-performing hot stamping is that there are different adhesive layers and poor coating. The adhesive layer of various types of galvanized aluminum is different, so the galvanic aluminum foil should be selected according to the actual situation of the material to be heated.

2 electrification of aluminum foil selection. The rational selection of electro-aluminum foil is one of the important factors for hot stamping the cover of books and periodicals. There are many kinds of electro-aluminum foils at home and abroad, with different performances and different quality. Therefore, the following two points should be taken into consideration when selecting:

The first is not to superstition abroad. Nowadays, there are many kinds of electro-aluminum foils imported, and the quality is generally good. However, because of different models and different materials for hot stamping, it is not always applicable to hot stamped materials. The second choice of anodized aluminum should first understand its performance, quality, etc., and then select according to the specific conditions of the material, texture, etc. of the material to be ironed, otherwise it will cause unnecessary waste and loss.

3 Electrochemical aluminum foil processing in the hot stamping process. Electrochemical aluminum foil varieties, manufacturing process, batch, performance vary, in addition to the correct selection should also pay attention to processing in the processing.

A. Before ironing a new processed product or using a new type of anodized aluminum foil, a simple visual inspection should be performed to see if the model is consistent with the material being hot-pressed; open the recoated aluminum foil and observe the surface of the film. Whether there is trachoma, scratches, wrinkles, and whether the feel is smooth, and whether the brightness meets the requirements. The good quality aluminum foil reflects strong light and sparkles. If the instrument is used to measure, the light reflectance should reach about 85% evenly. Unconditional can be determined visually.

B. Hot stamping Electroplated aluminum foil is generally available in copper plate (red copper), zinc plate, and copper plated zinc plate. When using copper plate as well, due to the heat resistance of the copper plate, good heat transfer, suitable elasticity, durable and hot stamping effect than the other two plates. If you are printing small batches of work or sheet paper, you can use zinc plate. The soft texture of zinc plate should not be excessively hot or the pressure is too large. Otherwise, the plate will be deformed and the hot stamping effect will be poor. Some units only use zinc plates, and sometimes they need to change the number of plates, causing great waste.

Hot stamping plate thickness is generally 1.5 ~ 2.5mm. Depending on the texture and thickness of the material to be heated, a suitable thickness of the plate is selected. If the hot stamping version is too thin, hot stamping may occur, such as blurring of flowers, etc. If it is too thick, it will cause waste.

Outside the hot stamping printing plate, before use, we must first check whether the layout of the burr is not smooth, edges and corners are not neat, the picture is not clear, etc., to the unqualified part of the corrosion, repair and then plate hot stamping.

C. Electrochemical aluminum foil inspection is completed, hot stamping version is good, we must first test hot; and according to stamping material texture, area, etc., or adjust the stamping of the temperature, time and pressure.

The above three points are the main links in hot stamping processing.

Hot stamping book shell pressure, in addition to fabric outside the general indentation depth of about 0.4mm; hot stamping time is generally 0.5 ~ 1S; hot stamping temperature is generally 110 °C ~ 145 °C. According to the flatness of the surface of the object to be heated, the type of material, etc., the correct selection of different pressure, time and temperature, in order to ensure the quality of hot stamping to achieve the desired effect.

(to be continued)