TABLE OF CONTENTS Heated tool welding, also known as hot plate, mirror, platen, butt or butt fusion welding, is a widely used technique for joining injection molded components or extruded profiles.
The process uses a heated metal plate, known as the hot tool, hot plate, or heating platen, to heat and melt the interface surfaces of the thermoplastic parts. Once the interfaces are sufficiently melted or softened, the hot plate is removed and the components are brought together under pressure to form the weld. An axial load is applied to the components during both the heating and the joining/cooling phases of the welding process.
Welding can be performed in either of two ways: welding by pressure or welding by distance. Both processes consist of four phases, shown in the pressure versus time diagram in Fig. 1.1.
In welding by pressure, the parts are brought into contact with the hot tool in Phase I, and a...
