If you’ve got a bubble in a plastic laminate countertop it’s not a good thing. This material is used on the majority of countertops in the world and usually provides years of service without complaint. In the kitchen, water is the enemy and countertops can be its victim. Generally they are watertight and not at risk, however, occasionally the plastic laminate does separate from the substrate (the plywood or particleboard underneath) and results in a “bubble” on the surface or as a loose corner that lifts when snagged. The laminate and substrate are glued together with strong contact cement and often when it loosens, heat and pressure can reactivate its holding power. Use a hot iron with a towel (to protect the surface) and then add weight (like books) for pressure until things cool down. When removed, it should look as good as new, without your having to add a drop of glue.