What heat resistance properties do plastic pellets used for small appliance casings meet for different power levels?
Publish Time: 2026-01-30
In modern homes, there is a wide variety of small appliances, from low-power fans and humidifiers to medium- and high-power electric kettles, coffee makers, air fryers, and even microwave oven accessories. The casing materials must strike a balance between aesthetics, cost, and safety. As a mainstream raw material for small appliance casings, the heat resistance of plastic pellets directly affects the structural stability, fire safety, and user experience of the product during long-term use. Different types of engineering plastics, through formulation modification, can be precisely matched to the heat load requirements of various small appliances, ensuring safe operation under "cold exterior, hot interior" conditions.1. Heat Resistance Classification: Material Spectrum from 80℃ to 150℃General-purpose polypropylene and high-impact polystyrene are commonly used in low-heat small appliances, such as table fans and electric toothbrush bases. Their heat distortion temperature is typically between 80–100℃, sufficient to handle motor temperature rise or high ambient temperatures, but not suitable for components near heat sources. For medium-power equipment, flame-retardant ABS or PC/ABS alloys are commonly used, with a HDT of 110–120°C, offering good rigidity. However, in high-heat applications—such as air fryer lids, coffee machine steam vents, and iron handles—high-temperature resistant engineering plastics are required, such as modified polyamides, polybutylene terephthalate, or polyphenylene sulfide, with HDTs exceeding 130–150°C and even capable of withstanding short-term thermal shocks of 180°C.2. Modification Technology Improves Synergistic Heat Resistance and Flame RetardancySimply improving the heat resistance of the substrate often sacrifices toughness or processability. Therefore, the industry generally adopts a composite modification strategy: adding inorganic fillers to PP or ABS can significantly improve heat distortion temperature and dimensional stability; introducing phosphorus-based or nitrogen-based flame retardants to replace traditional halogen-based systems can meet UL94 standards while avoiding the release of toxic gases at high temperatures; some high-end products also use nanocomposite technology to disperse nano-clay or silica in the polymer matrix, forming a "maze effect" insulation layer to slow down heat conduction to the interior. For example, if the shell of an air fryer uses 30% glass fiber reinforced PBT, not only will the HDT be increased to 210℃, but it will also have excellent creep resistance and electrical insulation.3. Structural Design and Thermal Management Work Together to Ensure SafetyThe heat resistance of plastic pellets materials needs to be matched with the product structure. Designers often set up air insulation cavities, heat-conducting ribs, or metal insert heat sinks in high-heat areas to guide heat to non-critical areas. At the same time, the shell wall thickness is optimized through CAE thermal simulation to avoid local overheating that could lead to softening and deformation. For example, although the handle of an electric kettle is close to the boiling chamber, its surface temperature can be controlled below 50℃ through a double-layer hollow structure combined with low thermal conductivity PP material, ensuring user safety.4. Material Innovation Under the Trend of Environmental Protection and RecyclingPlastic pellets With the advancement of sustainable development, environmentally friendly materials such as bio-based PP and recycled PC/ABS are gradually being applied. Through optimization with heat-resistant stabilizers and compatibilizers, some recycled materials can now meet the needs of low-to-medium power small appliances, reducing carbon footprint without sacrificing core performance.The casings of small appliances made of plastic pellets are not "one-size-fits-all," but rather engineering solutions tailored to power, heat source location, and safety level. From economical PP to high-performance PBT, the deep integration of materials science and structural design ensures that every small appliance operates efficiently while always prioritizing user safety. It is this "invisible heat-resistant protection" that truly integrates technology into daily life, providing peace of mind every moment.
