Common colors for HDPE welding rods are natural (creamy white), black, and blue/green/red (with custom logos). Diameters typically range from 2-6mm (3mm and 4mm are common), and lengths range from 300mm to 1000mm (customizable upon request).
Typical Applications and Application Areas
Pipeline Engineering and Municipal Maintenance
HDPE Pipe Repair: Used for crack repair, joint reinforcement, or hole filling in buried water supply, sewage, and chemical pipelines (welding rods are fused to the damaged area via heat fusion welding).
Pipeline Jointing Assistance: Use welding rods to fill gaps or create simple joints (such as temporary branch pipe connections) during on-site construction of large pipelines where heat fusion welding machines are not available.
Tank and Container Manufacturing
Plastic Tank Repair: Repairs cracks or pinholes in polyethylene (HDPE) chemical tanks and water tanks (welding rods are made of the same material as the tank to ensure corrosion resistance).
Custom Container Splicing: Fills the joint seams of small HDPE tanks (welding rods are used to enhance joint strength).
Industrial parts and equipment maintenance
Plastic equipment maintenance: such as local damage repair of chemical reactor covers and valve sealing surfaces made of HDPE (welding rods can restore component integrity);
Wear-resistant parts reinforcement: welding welding rods on the surface of HDPE guide rails and pulleys (increasing local thickness and improving wear resistance).
Agriculture and water conservancy facilities
Irrigation pipe repair: repairing leaks in farmland PE irrigation pipes (quick and easy, no need to replace the entire pipe);
Aquaculture ponds: welding cracks or seams in HDPE aquaculture ponds (resistant to seawater corrosion, extending service life).
Processing technology (welding method) and operation points
Mainstream welding methods
(1) Hot air welding (most commonly used)
Tools: hot air welding gun (temperature adjustable, commonly 200-250℃), welding rod (diameter matching welding thickness), scraper (cleaning substrate surface).
Steps:
① Clean the area to be welded (use acetone or alcohol to remove oil and dust);
② Use a scraper to roughen the welding surface of the HDPE substrate and the welding rod (roughen it to increase the bonding area);
③ Heat the end of the welding rod (use a welding torch to melt it into a liquid state);
④ Press the molten welding rod onto the area to be welded on the substrate (heat the contact surface of the substrate at the same time), and fuse the two by moving the welding torch or pressing manually;
⑤ After cooling, a strong weld is formed (the cooling time is about 1-3 minutes, depending on the thickness).
(2) Electric fusion welding (suitable for precision connection)
Tools: Electric fusion welding machine (welding sleeve with built-in resistance wire heated by electric current), HDPE parts with pre-embedded electric fusion joints.
Applicable scenarios: Pipe connection with high welding precision requirements (such as gas PE pipes). Welding rods are rarely used directly in this method (more often electric fusion pipe fittings).
(3) Butt-fusion welding (large diameter pipes)
Supplementary note: For large diameter HDPE pipes (such as DN100 and above), hot-fusion welding machines are usually used to directly butt the pipes themselves. Welding rods are mainly used for small area repairs or auxiliary connections.
Key Operational Points
Temperature Control: The welding temperature must strictly match the rod type (generally 200-250°C. A temperature too high will cause carbonization and decomposition, while a temperature too low will result in incomplete melting).
Surface Preparation: The welding surfaces of the base material and welding rod must be clean (free of oil, moisture, and dirt) and roughened (roughness Ra ≥ 50μm). Failure to do so will reduce the bond strength.
Welding Speed: During hot-air welding, the welding torch should be moved at a constant speed to avoid local overheating or incomplete melting. The weld deposit thickness should typically be 2-3 layers (with the total thickness slightly exceeding the gap in the base material).
Cooling Protection: After welding, allow the weld to cool naturally (do not use water cooling or external force). Otherwise, the weld may deform or become insufficiently strong.
Environmental Requirements: Avoid welding in rainy weather, strong winds, or temperatures below -10°C (low temperatures reduce material fluidity and affect fusion).
