Plastic Molding Terms

Contact Welding

• Heated tools are used in contact welding. Pinchers are heated up and then applied to the areas of plastic that need to be molded together. The two pieces of plastic are pressed together by the heated pinchers. As the heat is transferred from the heated pinchers to the plastic, the plastic becomes soft and molds together. Once the plastic has been pinched, it needs to cool to make the bond permanent.

High-Frequency Welding

• Electromagnetic waves are used when using high frequencies to mold plastic together. These waves work on the chemical properties unique to the plastic. The result is a softening of the plastic as the electromagnetic wave cause the plastic to heat. The plastic then begins to flow together in the mold to become one piece of molded plastic.

Hot Plate Welding

• A plate that matches the shape of joint that needs to be welded is used in hot plate welding. The hot plate is positioned between the pieces of plastic that need to be molded together. The ends are held up to the hot plate until they become soft and begin to melt. The hot plate is then removed and the pieces of plastic are pressed together. The two pieces of plastic must be held together until the plastic has cooled and the bond between the two pieces of plastic becomes permanent.

Induction Welding

• Induction welding heats the piece that's being welded by using electromagnetic induction. When using induction welding while working with plastic, it's necessary to place magnetic material into the plastic that will be welded together. The piece being heated through electromagnetic energy will become hot and bind together the pieces of plastic. As the heat is lost from the metallic compound that was placed in the plastic, the plastic compound becomes soft and flows together into one piece.