how to test water heater thermostat_mini cooper fuse box factory

23 2024-08

　　What material is used to make self recovering fuses (PPTC)

　　Self healing fuse (PPTC) is an electronic component used for overload protection, which can isolate current overload and automatically restore normal working state after the overload disappears. The PPTC fuse is made of a special polymer material, and under overload conditions, its resistance will quickly rise, limiting the passage of current. This article will provide a detailed introduction to the materials, manufacturing processes, and characteristics of PPTC fuses, as well as their applications in the field of electronics.

　　PPTC fuses are mainly composed of thermistor materials, insulation materials, and conductive materials. Among them, thermistor material is the core component of PPTC fuse, which has temperature response performance. When current passes through a fuse, heat is generated inside the material, causing the temperature of the thermistor material to rise. When the temperature exceeds the triggering temperature of the material, the thermistor material undergoes a phase transition from a low resistance state to a high resistance state, that is, the resistance value increases. This temperature response characteristic enables PPTC fuses to automatically disconnect the current, thereby providing overload protection.

　　In addition to thermistor materials, insulation materials also play an important role in the production of PPTC fuses. The selection of insulation materials requires good insulation performance and the ability to withstand certain voltages and currents. Common insulation materials include polypropylene, polyamide, polyether ketone, etc.

　　Conductive materials are used to connect PPTC fuses and circuits, mainly copper sheets or copper foils. Conductive materials need to have good conductivity and reliable contact performance to ensure that PPTC fuses can conduct current normally.

　　The production process of PPTC fuses usually includes the following steps: material preparation, material mixing, compression molding, sintering, and polishing. Among them, material preparation is the first step in making PPTC fuses, which requires preparing the required thermistor materials, insulation materials, and conductive materials. Material mixing is the process of uniformly mixing these raw materials in a certain proportion to ensure the uniformity of the final product. Then, the mixed materials are pressed into shape, usually using injection molding or extrusion processes. Next, the molded parts will be sintered to ensure a strong bond between the materials. Finally, polish the product to improve its surface flatness and smoothness.