Generally, it depends on the thickness of the plastic, such as sheet plastic or tubing. Normally, sheet varieties are bonded with heat. Glued tubing is specially made for this use with a solvent-based adhesive. In most cases, it consists of 3 items: a cleaner, a prepping solution, & a solvent glue. The same glue is used to glue PVC pipe, but the solvent might differ. It is extremely dangerous to inhale solvent-based glues. Don't let anything get into your eyes. The stuff isn't great for your skin either; you should wear gloves, although it’s fairly easy to wipe off.