Numbered plastic security seals are widely used in our daily life because it is durable, flexible, bending, and so on. Why it has these characteristics is determined by the plastic material?The majority of plastic seals are made from PP (polypropylene) and PE (polyethylene) with a certain proportion. PP (polypropylene) has a better stiffness can increase the hardness of the seal, while PE (polyethylene) can make the seal withstand low temperature. In addition, there are two types of printing, laser printing, and hot stamping. For laser printing, laser powder needs to be added to the plastic seal, with it, the printing will be dark and pretty. Welcome to Custom!