joining together by using heat and pressure.
Plastic manufacturers use this process of joining two or more thermoplastic films or plastic sheets by heating areas on the plastic to the temperature at which fusion occurs. Plastic heat sealing is usually reinforced by pressure.
A method of joining plastic films by simultaneous application of heat and pressure to areas in contact. Heat may be supplied conductively or dielectrically.
The process of joining two or more thermoplastic films or sheets by heating areas in contact with each other to the temperature at which fusion occurs, usually aided by pressure. 
a method of joining plastic films by simultaneous application of heat and pressure to areas in contact. Heat may be supplied conductively or dielectrically.