The process of hot plate welding uses a heated platen to melt the joining surfaces of the two halves of a thermoplastic part. The part halves are brought into contact with a precisely heated platen for a predetermined period. After the plastic interfaces have melted, the parts are brought together to form a molecular, permanent, and often hermetic bond. A properly designed joint welded under precise process control often equals or exceeds the strength of any other part area.
Hot plate welding is suitable for almost any thermoplastic material, but is most often used for softer, semi-crystalline thermoplastics such as PP and PE. Weld strengths approaching that of the parent materials can usually be obtained if correct welding procedures are followed.
Dissimilar material having similar melting points and melt viscosities can be hot plate welded provided they are chemically compatible.