3LPP VS 3LPE Comprehensive Comparison

1. Structural selection comparison

2. Comparison of structural composition

According to their structures after construction and installation, 3LPE (3-layer-polyethlene) and 3LPP (3-layer-polypropylene) are composed of 3 different structures.
The innermost layer is epoxy primer (EP), but their performance is different. 3LPE uses 2B type, and 3LPP uses 2C type. The middle layer is a hot melt adhesive layer.
The outermost layer is radiation cross-linked polyethylene and radiation cross-linked polypropylene respectively. When manufacturers supply goods, the materials generally provided mainly include two parts: one is primer and corresponding curing agent, and the other is heat shrink tape.
The above-mentioned intermediate layer structure adhesive is fused with the inner surface of the heat shrink tape when it leaves the factory. When it is necessary to heat it at an appropriate temperature when patching on site, the liquid adhesive can be precipitated to stick the 3-layer structure together. After cooling, a solid 3-layer structure is formed and the anti-corrosion layer of the pipe itself can also match.

3. Comparison of structural performance

The main difference between 3LPE and 3LPP is that the three-layer structure can withstand different temperature requirements.

4. Comparison of construction requirements
Because the above two have different performance requirements, there are also differences in the construction process requirements of heat shrinkable tape patching, especially in terms of primer heat resistance and heat shrinkable tape heating temperature requirements, 3LPP heat shrinkable tape has its own special requirements.

5. Construction process comparison
(1) Dry film method
3LPE heat shrink tape patching process: preheating → sandblasting to remove rust → roughening the overlapping layer → applying primer → wrapping heat shrink tape → heating and shrinking the anti-corrosion tape (to remove bubbles) → secondary tempering → flattening heat shrink tape → sealing with rubber strip
3LPP heat shrink tape patching process: preheating → sandblasting to remove rust → roughening the overlapping layer → applying primer → wait for about 24 hours for the primer to dry → heating primer → wrapping heat shrink tape → heating and shrinking the anti-corrosion tape (to remove bubbles) → secondary tempering → Flat anti-corrosion tape → Sealing with rubber strip
(2) Wet film method
3LPE heat shrink tape patching process: preheating → sandblasting to remove rust → roughening the overlapping layer → applying primer → wrapping heat shrink tape → heating and shrinking the anti-corrosion tape (removing bubbles) → secondary tempering → flattening the anti-corrosion tape → sealing with rubber strip
3LPP heat shrink tape patching process: preheating → sandblasting to remove rust → roughening the overlapping layer → applying primer → heating primer → wrapping heat shrink tape → heating and shrinking the anti-corrosion tape (removing bubbles) → secondary tempering → flattening the anti-corrosion tape → sealing with rubber strip