Adhesive Resin (Hot Melt Adhesive) for Metal-Plastic Composite Pipes

As a critical interlayer, adhesive resin (hot melt adhesive) achieves molecular interlocking and stress transfer between dissimilar materials in metal-plastic composite pipes. Through high-temperature melt co-extrusion, it permanently bonds the metal skeleton and plastic protective layer, endowing the pipe with dual merits: the structural strength of metal and the corrosion resistance of plastic.

Core Functions & Mechanisms

1. Interfacial Bridging

It addresses the poor adhesion issue caused by the huge surface energy gap between non-polar plastics (PE/PP-R) and metals. Polar grafted groups (e.g., maleic anhydride) form chemical bonds and physical anchoring with metal substrates.

2. Stress Buffering

It absorbs internal stress generated by mismatched thermal expansion coefficients of metal and plastic, preventing delamination and debonding under repeated temperature cycling.

3. Integrated Structural Bonding

In the five-layer pipe structure (Plastic – Adhesive – Metal – Adhesive – Plastic), the resin acts as a continuous transition phase, ensuring coordinated deformation of all layers without peeling during bending or pressure bearing.

Main Application Scenarios & Pipe Types

1. Aluminum-Plastic Composite Pipes (PE/AL/PE, PEX/AL/PEX)

Widely used in domestic cold/hot water supply, floor heating and gas piping systems. Specialized adhesives withstand sustained 95°C high temperature and long-term hydrostatic pressure, with excellent oxygen barrier performance.

2. PPR Aluminum Stabilized Pipes

Suitable for high-temperature hot water and heating systems. The adhesive layer matches the melting point of PP-R, maintaining intact interfacial bonding during hot melt connection.

3. Plastic-Steel Composite Pressure Pipes (PSP)

Applied to municipal water supply and industrial fluid transportation. The adhesive layer resists intense mechanical stress and harsh corrosive environments, compatible with electromagnetic fusion fittings.

4. Special Functional Pipes

Including steel wire reinforced pipes and oxygen barrier pipes. Custom adhesive resins are developed to fit various metal forms (steel wire, aluminum foil) and plastic substrates.