How to Test the High-Temperature Resistance of PTFE Insulated Wires

Regarding our earlier conversation about the compatibility assessment and the temperature resistance requirements of PTFE insulated wires for hot runner applications, the below mentioned step-by-step testing procedures can be followed to check their capability to endure high temperatures:

Standard Constant Temperature Aging Test: Put the wire sample into a 260℃ high temperature oven and roast for 720 hours continuously. Inspect the insulation resistance and tensile strength of insulation layer before and after the test. Qualified if less than 20% change rate, confirming long term temperature stability.

Instantaneous high temperature impact test: Put the wire into 320℃ high temperature environment for 10 minutes. Once removed, ensure the insulation layer has not softened, melted or cracked, therefore indicating it can endure the severe high temperatures of hot runners instantaneously.

High and Low Temperature Alternating Test: 50 cycles of alternating high and low temperature in -65℃ ~ 260℃ complete

The insulation layer is not expected to harden, break or peel, hence exhibiting suitable for wide temperature range functioning of hot runners. Actual operating condition simulation test: The PTFE conductor was attached to the hot runner system and underwent 100 step temperature rise and fall cycles. No substantial drift in dielectric constant was recorded during the whole cycle, which confirms its temperature resistant durability under real world working circumstances.

The PTFE conductor passed the above test is fully suited for the hot runner system's long-term high-temperature operation requirements, solving the problems of anomalous increase of distributed capacitance and temperature control lag caused by insulation aging.