Everyone knows that double-wall heat shrink tubing has excellent insulation, sealing and waterproof properties, but many users do not know what material double-wall heat shrink tubing is made of. Today, the editor of DWUAI heat shrink tubing manufacturer will take you to decipher it.

    There are only two main materials for double-wall heat shrinkable tubes: PE polyethylene and hot melt adhesive co-extrusion. Plus a small amount of other auxiliary materials, such as flame retardants, color masterbatches and inks. Each of the materials has a clear division of labor and functions. Let’s explain the uses of each material in detail.

Polyethylene (PE) is the main raw material, accounting for about 80%. It is mainly used for the outer insulation protective layer. It has excellent wear resistance and can play the role of insulation protection.

    The inner layer is a waterproof sealing layer, which uses hot melt adhesive. Hot melt adhesive has the characteristics of melting when exposed to heat and solidifying when cooled. It can fill the gap between the heat shrink tube and the product to enhance the sealing. Because the inner wall of double-wall heat shrink tubing is covered with hot melt adhesive, double-wall heat shrink tubing is also called glued heat shrink tubing. Because of the unique properties of hot melt adhesive, double-wall heat shrink tubing has excellent sealing and waterproof capabilities.

    There are two commonly used flame retardants, magnesium hydroxide and phosphorus flame retardants, which are mixed in the main agent polyethylene according to a certain proportion. The most important function is easy to understand according to the literal meaning. The main purpose of adding flame retardant is to make the heat shrinkable tube have flame retardant properties.

    The purpose of adding color masterbatch is also very simple. It is mainly used for color mixing. For colored double-wall heat shrinkable tubes, a certain proportion of color masterbatch needs to be added to achieve the desired color, such as red, yellow, green, and blue. , white and other conventional colors need to be mixed with masterbatch.

    Finally, the ink is mainly used for printing on the surface of double-wall heat shrink tubes, and the ink accounts for the smallest proportion in the entire ingredient list. If there is no printing on the surface, there is no need to use ink. Normally, double-wall heat shrink tubes are not printed unless there are special requirements.

    The main materials of double-wall heat shrinkable tubes are PE polyethylene and hot melt adhesive, plus the auxiliary materials flame retardant and color masterbatch. Although the raw materials for producing double-walled heat shrinkable tubes are simple, they are very important in the entire wire harness and tube. It has an irreplaceable sealing, shock-absorbing and waterproofing effect in the road field.