What Are Adhesives? At their most simple, adhesives are substances used for sticking objects or materials together. In scientific terms, those substances that are sticking together, regardless of what they are, become known as "substrates." Think of a peanut butter and jelly sandwich. You could say the peanut butter and jelly is an adhesive for the two pieces of bread, the substrates. Many adhesives are made for specific purposes, depending on the industry and the substrates that need to be bonded together. For instance, there might be a special glass adhesive for a car window, but a completely different one for a coffee table. Each has its own unique formula and is specifically designed for a particular need. What's in an Adhesive? Adhesives are most often made from polymers or resins, which are chemical structures that can eventually be recognized as plastics. However, that's not all that can be found in adhesives. They can also contain: ·Animal Product ·Milk ·Polyurethane ·Acrylate ·Nickel ·Rubber/Latex ·Acrylic ·Nylon ·Silicone ·Copper ·Plants ·Silver ·Epoxy ·Polyester ·Starch ·Grains ·Acrylic ·Vegetables ·Graphite ·Oil ·Water Think about going to the craft aisle and seeing all the different glues. No one is the same as the other, which is why you might use tacky glue for repairing a broken trophy but a glue stick for your kid's art project. The substances above work in the same way. One could be good for adhesives used in construction, while the other works better for stamps and envelopes. It just depends on the manufacturer and their need. How Are Adhesives Classified? Adhesives are often broken into two types, depending on how they're made. They are classified as either pressure sensitive or polymer-based, though there are also other classifications that include: 1. Anaerobic 9. Plastisol 2. Bismaleimides 10. Polyvinyl Acetate (PVA's) 3. Casein 11. Reactive 4. Cyanoacrylate 12. Solvent-Based 5. Dextrin 13. Thermoset 6. Electrically conductive 14. UV Curing 7. Hot melt 15. Water-Based 8. Phenolic What Are Pressure Sensitive Adhesives? Pressure sensitive adhesives consist of acrylics, rubber/latex, or silicone. They don't need a solvent, water, or heat to stick and can be applied with light pressure to paper, glass, wood, plastic, or metal. What Are Polymer-Based Adhesives? Polymer adhesives are broken up into polyester, polyurethane, acrylate, and epoxies. Polymer-based adhesives are considered the best for bonding woods, but are actually used in many other industries. Ultimately, adhesives are classified based on whether or not they use a solvent, water, heat, or any combination of the three to stick to a surface. Here are the other ways they can be classified: ·Hot Melt Hot melt adhesives are heated to melt and then cooled to solidify and bond materials. They're also referred to as polyamides and work best for woodworking projects, packaging, and trade show exhibits. ·Bismaleimide Bismaleimides are also referred to as BMI adhesives. They are used in electronic circuit boards, but also join metals, glass, ceramics, and some plastics. ·Cyanoacrylate Have you ever fixed something with Super Glue? Well, then you've used a cyanoacrylate adhesive! Cyanoacrylates react with moisture and work best for super gluing plastic or rubber objects. Which Industries Use Adhesives? Almost every industry can use adhesives in some capacity. However, there are a few that couldn't function or exist without them. This material has contributed to many essentials we use almost every day. ·Arts & Crafts Creative genius would be impossible without adhesives! How else can you build a diorama of the solar system for your kid's science fair? ·Automotive Many car parts are held together thanks to adhesives. You can find them everywhere from body work to the sweet emblem on a fancy BMW. ·Construction Landmarks like the Eiffel Tower or Golden Gate Bridge wouldn't exist without adhesives. Aside from bolts, screws, gussets, and other finishes, this is what helps each piece stick together. ·Dental While it may seem strange, some adhesives can be found in your mouth. They are often used for braces or dental restoration procedures. ·Food Bags of potato chips, bottled drinks, and many other delicious snacks are sealed with adhesives. If the bag is hard to open, that just means the adhesive is really doing its job! ·Interior Design You will find adhesives in some furniture and wallpapers. Ultimately, these decorative touches are what help create that "home sweet home" feeling ·Medical Bandages, gauze, and other medical essentials are designed with adhesives. That's why it hurts so much when you have to peel off a Band-Aid®. ·Promotional Products Popular advertising giveaways like PopSockets™ and cell phone wallets rely on adhesives to work. These logoed gifts tend to stick in people's minds. Source: https://www.qualitylogoproducts.com/promo-university/different-types-of-adhesives.htm