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TPGOA Technical Insights

Hot Plate Welding

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.

Advantages of hot plate welding include precise control of the melt temperature, excellent weld strength, ability to weld large, complex parts, and ease of attaining hermetic seals.

The simplified diagram below shows the stages in the hot plate welding process:


  1. Parts are loaded in their nests.
  2. The heated platen moves forward between the parts.
  3. The parts contact the heated platen. The plastic begins to melt.
  4. After the parts' joint interfaces are plasticized, the nests move back allowing the heated platen to retract.
  5. The parts are pressed together so that a molecular bond forms.
  6. The nests move apart and the finished assembly is unloaded.
TPG makes every effort to insure that the information contained herein is accurate - however, we accept no liability for the content of this piece, or for the consequences of any actions taken on the basis of the information provided.
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