I. Introduction

The epoxy fiberglass reinforced coating for HDD is composed of modified solvent-free epoxy adhesive and glassfiber. The modified solvent-free epoxy adhesive is a two-component reactive material, in which, Part A is composed of modified epoxy resin, various auxiliaries and high strength wear resistant filler while Part B is an effective curing agent with good temperature resistance and damp and hot resistance. The modified solvent-free epoxy adhesive has good mechanical properties such as wear resistance and scratch resistance, and combined with fiberglass, the formed epoxy GRP is particularly applicable to protect HDD pipes.

II. Structure

The epoxy GRP is particularly suitable to protect 3LPE coated pipeline in the horizontal directional drilling (HDD). The total thickness of the external coating should not be less than 1.2 mm. A variety of structure could be chosen such as 2-ply glass-fiber cloth + 5-ply adhesive, 3-ply glass-fiber cloth + 6-ply adhesive, and 4-ply glass-fiber cloth + 7-ply adhesive. However, the detailed structure and the application process should be specified in the design specification.

2-ply glass-fiber cloth + 5-ply adhesive are applied as follows:

Epoxy resin (touch dry) + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin (touch dry) + epoxy resin;

3-ply glass-fiber cloth + 6-ply adhesive are applied as follows:

Epoxy resin (touch dry) + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin (touch dry) + epoxy resin;

4-ply glass-fiber cloth + 7-ply adhesive are applied as follows:

Epoxy resin (touch dry) + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin + glass-fiber cloth + epoxy resin (touch dry) + epoxy resin.

III. Application

The external protection of 3LPE coated pipeline through the hard rock area, stone-rich area, rocky area and gravel-rich area.

IV. Features

1. Good adhesion to both metallic and non-metallic substrates;

2. Good liquid-tightness and waterproof performance, acid resistance, alkali resistance, salt resistance, perfect corrosion resistance;

3. High hardness, scratch resistance, wear resistance, good flexibility and impact resistance;

4. Good application operability , wide application temperature range from 0℃ to 70℃, high operability by mechanical spraying or hand brushing, application quality is controllable.