Phenolic resin is formed by polycondensation reaction of phenol and aldehyde materials in the presence of acid or alkali catalysts. Commonly used phenolic materials include phenol, toluene, and xylene

Ventilation duct occupies a more important position in ventilation and air conditioning. It has a large construction area, a long construction period, and a relatively large proportion of the total cost.

When galvanized air ducts pass through walls, use non-combustible thermal insulation materials such as rock wool to seal. When installing the galvanized air duct, it should be installed while passing through the nylon wire, so that the running light can be used for the tightness test.

In buildings, materials used to control the outflow of indoor heat are traditionally called thermal insulation materials, and materials that prevent outdoor heat from entering the room are called thermal insulation materials.

Thermal insulation cotton is a non-toxic, harmless and non-polluting new thermal insulation material made of high-purity clay clinker, alumina powder, silica powder, chromite sand and other raw materials.