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Why are the heater plates of hot plate welding machines coated?


Frequently Asked Questions

The surface of the heater plate is usually coated with PTFE to prevent molten material from sticking to it. For flat plates, PTFE-coated glass fibre fabric is usually used. Complex heater plate surfaces tend to be spray coated with a uniform layer of PTFE, typically 50µm thick. However, PTFE cannot be used at temperatures greater than about 270°C. For higher temperature welding operations, uncoated aluminium-bronze plates are used to minimise adhesion of the molten polymer.

With or without a coated plate, it is important to ensure that no molten polymer adheres to the plate, since this will cause contamination in subsequent welds. If this is a problem, the plates should be cleaned between each weld.

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