I. Core Principles of Temperature Setting
1. General Recommended Temperature: 260℃–270℃
Most authoritative construction guidelines and manufacturer specifications recommend setting the heat fusion machine temperature within this range.
Too low a temperature (<253℃) will result in only slight melting of the surface, forming a "false weld" with insufficient connection strength.
Too high a temperature (>280℃) will cause excessive softening or even carbonization of the PPR material, leading to reduced inner diameter, brittle joints, and potential leaks under pressure later.
2. Adjusting the Temperature According to Pipe Diameter
Small pipe diameter (20–32mm): A temperature of 260–265℃ is recommended for even heating.
Large pipe diameter (40mm and above): It is recommended to increase the temperature to 265–270℃ to ensure sufficient heat conduction and fusion of the thick-walled material.
3. Considering Environmental and Material Factors
Winter Construction (Ambient Temperature Below 10℃): It is recommended to raise the temperature to 265–270℃ and extend the preheating time to prevent excessive heat loss.
Summer High Temperatures: Maintain 260℃ or even slightly lower (e.g., 255℃) to avoid over-melting of materials.
When using thin-walled or low-cost pipes: Careful temperature control is necessary to prevent diameter reduction due to rapid heat conduction.
4. Equipment Temperature Control Accuracy Affects Actual Results
Some inexpensive hot melt machines on the market have a large discrepancy between the "digital display temperature" and the "actual die head temperature," with measured errors reaching ±30℃ or more.
It is recommended to equip the machine with an infrared thermometer for regular calibration to ensure accurate temperature control and avoid situations where the temperature is set to 280℃ but only reaches 240℃.
II. Supplementary Operating Points
1. Proper Preheating: After turning on the machine, wait for the constant temperature light to illuminate stably. Some models require a second green light before use to ensure uniform heating plate temperature.
2. Avoid operating based on experience: Do not rely on visual methods such as "smoking indicates heat," and strictly follow the temperature control instructions.
3. Observe the weld quality: A qualified weld should show a uniform and symmetrical "double eyelid" molten edge, without charring, stringing, or misalignment.
