Why the heater need to be washed?

Infiltration, in physics and engineering, infiltration (also known as growth) infiltration. Permeation (e.g. liquid, gas or steam) through a solid. It is directly related to the concentration gradient permeation, the intrinsic permeability of materials, and the mass diffusion coefficient of materials.
When you have any type of permeable material such as a fluoropolymer heater sheath, chemistry can permeate gas or steam in the form of sheaths. In life, you can see a balloon inflated a few days later. There are no holes in the balloon, but the air will slow down the leakage through the "plastic" material because it is permeable. With fluoropolymer process heaters, more active chemistry, the faster this process will occur.
Although fluoropolymer materials are almost all solutions to chemical inertia, they have absorption and permeability characteristics. Highly active chemical reactions (especially at higher temperatures and pressures) migrate through the fluoropolymer sheath of the electric heater and attack elements in stainless steel containers. This penetration may greatly shorten the service life of the heater.

The purifying elements of the process are designed to release gas flow to clean the environment around the heating element. The airflow sweeps over a large amount of internal moisture, resulting in the accumulation of particles due to infiltration through the heater sheath. This patented feature solves the permeability problem and promotes longer life of a heater.

Anticorrosion Pigments, Inkjet Receptive Coating, Matting Agent