How to identify the advantages and disadvantages of PTC materials for electric heating cables?

PTC material is the most important material in the production of electric heating cables. It often refers to semiconductor materials or components with a large positive temperature coefficient. PTCs are typically referred to as positive temperature coefficient thermistors. As the ambient temperature decreases, the resistance of a PTC decreases, while its heat generation increases. This PTC material, when used in electric heating cables, allows them to achieve optimal temperature control in the shortest possible time. The quality of the PTC material can determine the quality of the cable. Here's how to distinguish it.
... 3. Combustion Test: Expose the PTC core of the heating cable to an open flame. Non-flammable materials are considered superior, while flame-retardant or flammable materials are considered inferior. However, halogen-containing flame-retardant materials should be prohibited. While flame-retardant, halogen-containing materials produce thick smoke and are toxic, making them more harmful than flammable materials. In other words, while flame-retardant, they are considered obsolete and non-environmentally friendly.

4. Softness and Hardness: Materials with greater hardness generally have higher density and price. For example, low-density polyethylene (LDPE) is soft and inexpensive, with a temperature rating of only 70°C and requiring radiation cross-linking to withstand 90°C. High-density polyethylene (HDPE) is hard and expensive, with a temperature rating of 90°C and a temperature resistance of 130°C after radiation cross-linking. The quality of a product is determined by its performance.