Petroleum asphalt,

intermediate materials for glass mesh 

glass mat, etc.

Coal tar pitch, 

intermediate materials for glass mesh glass mat, etc.

Coal tar epoxy mixture, 

glass cloth, etc.

Polyethylene, 

polyvinyl chloride (strip)

High (low) density 

polyethylene (pellets)

Polyethylene, 

epoxy resin, 

phenol resin (powder)

General: 

1 internal layer, 1 outside layer

strengthened: 

2 internal layer, 2 outside layer 

particularly strong: 

2 internal layer, 2 outside layer

Continuous coating closely adhered to the wall, 

forming a hard shell

Coating melted in the wall, 

form a continuous solid film

Thickness

(mm)

Ordinary ≥4.5

strengthen≥5.5 

particularly strong ≥7 

Ordinary ≥3

strengthen≥4.5

particularly strong ≥5.5

Ordinary ≥0.2

strengthen≥0.4

particularly strong ≥0.6