Last week, we received an urgent order from an injection molding factory in Bangkok, Thailand, which specializes in automotive interior parts production. The customer needed 35 cartridge heaters with a diameter of 12mm and length of 250mm, requiring a surface power density of 18W/cm² to meet the needs of rapid heating and stable temperature control of the mold.
After receiving the order, the technical department immediately confirmed the details with the customer: the customer's mold is used to produce car door trim strips, the injection material is modified PP, the molding temperature needs to be stable at 180℃±5℃, and the internal space of the mold is limited, requiring extremely high dimensional accuracy of the cartridge heaters. We immediately started the customization process, using 304 stainless steel as the sheath material, paired with nickel-chromium heating wire and high-purity magnesium oxide powder filling to ensure uniform heating and standard insulation performance.
During production, the workshop strictly controlled the tolerances according to the customer's requirements: the pipe diameter error was controlled within ±0.05mm, and the cold end length was accurately set to 20mm to avoid interference with the cooling pipes inside the mold. The wire winding process used fully automatic equipment to ensure uniform spacing of the heating wire, with the power deviation controlled within ±3%. The formed cartridge heaters were processed through a pipe shrinking process, so that the filling density of magnesium oxide powder reached 3.3g/cm³, greatly improving the heat conduction efficiency and mechanical strength.
The inspection link was the focus of this order. Each cartridge heater underwent a 15-minute dry burning test, with the surface temperature stably above 450℃ without local overheating; the cold-state insulation resistance test results were all ≥100MΩ, far higher than the industry standard of 50MΩ; the high-voltage resistance test passed the 2000V/1min assessment without breakdown or excessive leakage current. In addition, we simulated the customer's mold environment, embedded the cartridge heaters into the test mold for 8 consecutive hours of heating-insulation-cooling cycle tests, and the temperature fluctuation was always controlled within ±3℃, fully meeting the customer's production needs.
In the packaging link, custom foam-lined cartons were used, with each cartridge heater wrapped independently to avoid collision damage during transportation. At the same time, we attached detailed installation instructions and inspection reports, with key precautions marked in Thai to facilitate on-site installation and acceptance by the customer.
Currently, these cartridge heaters have been shipped to Thailand via the China-Laos-Thailand Railway and are expected to arrive at the customer's factory in 5 days. The customer's purchasing manager stated after confirming the shipping information that they had used cartridge heaters from other brands before, but the slow heating speed and poor temperature stability led to low product qualification rates, hoping that our products can solve this problem. Our after-sales team has also established contact with the customer and will provide remote technical support during equipment installation and commissioning to ensure the smooth put-into-use of the cartridge heaters.
