When working with plastic materials as crafts or repairing materials, choosing the proper glue is essential. Because of the make-up of plastic as well as how slick and hard most plastics usually are, many types of glue will not properly adhere to a plastic surface. There are a few specific glue types to consider that will provide the best results for gluing plastic materials.
Epoxy glue is a high-strength adhesive that typically comes in two separate containers and is mixed together just prior to use. Epoxy is both extremely strong and durable and as such is commonly used in industrial projects such as car or aeroplane manufacturing. If you're working with heavy plastics or large pieces that may see severe outdoor wear and tear, then epoxy is your best bet. The glue will not only produce an incredibly strong bond but it is also waterproof and resistant to heat and chemicals. You must take care when using epoxy however, as it will require you to mix the two portions together thoroughly and then use the resulting adhesive rather quickly before it begins to set and get tacky.
Cyanoacrylate is often referred to as "superglue" because of it's incredibly strong adhesive power on most surfaces. The benefit to this type of glue on plastics is that only a small amount is required to create a lasting bond, meaning small projects involving plastic can be accomplished relatively quickly and cheaply. Cyanoacrylate is a universal adhesive so you will also find it a useful solution for gluing various non-plastic materials to a plastic surface. This glue is very fast drying and is best used for small bonding areas rather than larger pieces of plastic, which would be much better suited to epoxy. However, if you're working with various types of plastic along with other materials and aren't sure which glue to settle on, chances are cyanoacrylate is universal enough to get the job done.
Hot-melt glue is commonly used in small home projects and craft projects due to its easy-to-find and inexpensive nature. This glue type is usually referred to as "hot glue" and comes in preformed sticks that are passed through a hot glue gun. Similar to soldering a wire, the stick of glue melts inside the gun and is dispensed through the tip as a molten glue liquid, which can then be applied to a plastic surface. Once the plastics are bonded together with the glue it begins to dry, creating a strong and durable permanent bond. Because the glue is so hot when it's applied in its melted state it also partially melts the plastic, in essence creating one solid piece once dry. Like cyanoacrylate, this glue is best suited for small plastic bonding projects or for smoother surfaces that may not lend themselves well to standard glue.