Adhesives are natural or synthetic substances primarily used as glue. The first natural adhesives date back thousands of years and were made from a variety of trees, plants, starches, flour, and certain animal skins. In ancient times, these organic materials were mixed with water to create a sticky paste substance. Since then, adhesive production has become a more varied and complex process. The development of synthetic, thermoplastic, and pressure sensitive adhesives has improved the durability and range of use for this product. Adhesives now play a vital industrial role, whether they are used in complex mechanical processes or to close simple machine fractures.