What kind of glue is used in making hardboard?

The glue commonly used in making hardboard is phenolic resin, which is a type of thermosetting adhesive. This resin is mixed with wood fibers under heat and pressure to bond them together, creating a dense and durable board. In some cases, urea-formaldehyde or other synthetic adhesives may also be used. These adhesives provide the necessary strength and moisture resistance for hardboard applications.