Hot stamping Machine

There are Five types of hot stamping presses according to the stamping methods and substrate's shapes.

     Hot stamping machine and heat transfer machine are special printing equipment that transfer the metal coating on the hot stamping film or the printing pattern on the heat transfer film to other products. Distinguished from heat transfer machines: Machines that use various hot stamping films are called hot stamping machines, and machines that use heat transfer films are called heat transfer machines. However, both the bronzing machine and the heat transfer machine can complete the conversion of functions through necessary structural upgrades, and it is actually difficult to distinguish them. For the convenience of expression, there is only a literal difference between a hot stamping machine and a thermal transfer machine, and there is actually no obvious difference in their process and structure.
    Bronzing machine and thermal transfer machine are both heat-pressing machines, which use heat and pressure to transfer graphics and text. Plane machines use heating tubes and heating plates. Silicone roller machines use radiation way of heating.
   The main considerations for the hot stamping machine and heat transfer machine are: what kind of hot plate and silicone roller to use;

•       Heat transfer Process

​

•       Hot stamping Process:

​

Plain hot foil stamping process

    

1) Hot stamping text and patterns on flat products.

      This form is the most common. The product itself does not contain any type of graphics and text. To perform bronzing on it, it is necessary to make a graphic-text silicone template or a metal template. Bronzing relies on the difference in pressure and temperature to form graphics on the surface of the product. Only the graphics on the hot plate can form a mirrored reverse graphics on the surface of the product.

2) Foil stamping on the raised part of the flat product.

This form is more common in the plastic hot stamping industry. During injection molding, graphics and text can be engraved on the mold, so that the injection molded product has a raised part. In order to express enough eye-catching metal features on the raised part, a flat hot stamping machine is an important option. At this time, you only need to paste a flat silicone plate on the hot plate of the hot stamping machine. Obviously, the raised part will be in contact with the ironing plate to transfer the foil, and the non-contact part will not transfer the foil.

3) Bronzing on non-planar products.

In order to increase the difficulty of imitation, many plastic products or resin products avoid using flat structures, and use spherical or smooth curved special-shaped surfaces. If you want to perform hot stamping on such products, in addition to making rigid support fixtures, the production and product shape A highly consistent silicone mold becomes extremely important. Due to the shrinkage of injection molding products, there may be obvious size differences between the design draft provided by the user and the actual product. To complete exquisite bronzing, it is necessary to make a very complicated silicone mold, and make fine adjustments based on the actual size of the product and the deformation rules of the design draft. The adjustment on non-planar products has stricter requirements on the pressure and balance, and the use of metal plates should be avoided.

4) Embossed embossing
      Embossing embossing is an excellent representative of the paper foil stamping process, which requires embossed stamping patterns on the paper. The most obvious feature of concave-convex embossing is the use of two upper and lower sub-molds that are opposite to each other. The upper mold is a concave copper plate mold, and the lower mold is a graphic resin mold. During the embossing process, the concave die and the convex die press the paper tightly, and the embossed hot stamping pattern will be formed on the contact part of the hot stamping paper and the concave die.

Hot stamping fixture for hot foil stamping machine

   Hot stamping, especially the hot stamping of injection molded products, involves very complicated product shapes, and fixtures with good stability and certain strength must be made. Almost every kind of product requires a specific jig, and it should be said that the jig is the primary factor to complete the exquisite bronzing of the product. The jig of the hot stamping machine should have the following characteristics:
    1) High pressure resistance.
    Hot stamping machines have greater pressure than pad printing machines and screen printing machines, and the fixtures need to withstand greater pressure, usually made of metal materials
    2) Ensure good contact between the bronzing surface and the ironing plate
    If the hot stamping surface of the product is not flat, it must be ensured that the contact surface between the hot plate and the product has a good contact point
    3) Good interchangeability
    For turntable hot stamping machines and some automatic hot stamping machines, the fixtures of the products must ensure good tolerance and interchangeability to ensure that the hot stamping position of each product is accurate and effective
    4) Pay attention to the shrinkage of plastic
    Some plastic products tend to have dimensional deviation and deformation, and the fixture should be able to support the product and be able to adapt to most products.

 

• Temperature control: When hot stamping on plastic products, temperature control is crucial. Different types of plastics have different softening points and melting points, so the hot stamping temperature should be adjusted according to the material of the plastic. Generally speaking, the hot stamping temperature is between 100-200℃. For example, for ABS plastic products, the hot stamping temperature can be set at around 120-150℃, which can ensure the smooth transfer of the metal coating on the hot stamping foil without deforming the plastic product.

• Pressure adjustment: Appropriate pressure can ensure that the hot stamping foil fits tightly with the plastic product and that the metal coating is completely transferred to the plastic surface. The pressure is adjusted according to the shape, thickness and hardness of the plastic product. If it is a flat plastic plate, the pressure can be relatively small; for plastic products with a certain curvature, such as plastic cups, the pressure needs to be appropriately increased to ensure that the hot stamping pattern can also be clear and complete on the curved surface. The pressure usually ranges from 2-8kg/cm².

• Time control: The time of hot stamping will also affect the final effect. If the time is too short, the metal coating on the hot stamping foil may not be fully transferred; if the time is too long, the surface of the plastic product may be damaged or the hot stamping pattern may be blurred. The general hot stamping time is between 0.5 and 3 seconds, and the specific time should be determined according to the actual hot stamping temperature, pressure, and the material of the plastic and hot stamping foil.