Blue 6mm OD 4mm ID Pu Air Hose

Our company is located in Yantai, Shandong, the birthplace of polyurethane products in China, which is also the location of one of the raw material manufacturers in China, Wanhua. We have been established for nearly 20 years, and our products mainly include polyurethane wheels, polyurethane air hoses, polyurethane sheets, polyurethane screens , polyurethane forklift covers, polyurethane scrapers, polyurethane pipeline pigs and other polyurethane products. The production line for introducing polyurethane air pipes has been in operation for nearly 10 years. Only in the production of polyurethane air hose, we have 7 advanced extrusion production equipment and multiple testing equipment to ensure the quality requirements of every link in the production of blue 6mm OD 4mm ID pu air hose.

Our Blue 6mm OD × 4mm ID PU air hose is produced using a continuous extrusion molding process, ensuring consistent quality, precise dimensions, and excellent performance for pneumatic applications.

1.Raw Material Selection & Drying

Made from high-grade thermoplastic polyurethane (TPU) pellets (polyester or polyether types available based on oil-resistance and wear-resistance requirements).

Custom blue color is achieved with dedicated color masterbatches.

TPU pellets are thoroughly dried before processing to prevent moisture-induced bubbles and ensure a flawless surface finish.

2.Extrusion Molding (Core Step)

1)Melting & Homogenizing: Dried TPU pellets are melted and uniformly mixed inside the extruder barrel via heating and screw shearing.

2)Die Shaping: The molten material is forced through a specialized tube die featuring a centrally positioned mandrel, creating a ring-shaped gap that forms the hollow tube profile.

3)Precision Control: The die dimensions are slightly larger than final specs to compensate for downstream stretching and shrinkage. Real-time laser diameter gauging with closed-loop feedback automatically adjusts puller speed or extrusion output, guaranteeing tight tolerances for 6mm OD and 4mm ID.

3.Vacuum Sizing & Cooling

1)The hot extruded tube immediately enters a vacuum sizing tank, where vacuum pressure holds it firmly against the sizing sleeve to lock in the outer diameter.

2)Simultaneously, water spray or immersion cools the tube, solidifying its shape and ensuring dimensional stability.

4.Haul-off, Printing & Winding

1)A caterpillar haul-off unit pulls the cooled hose at a precisely matched speed to maintain uniform wall thickness.

2)Optional surface printing (specifications, brand logos, etc.) is applied as per customer requests.

3)The finished hose is wound into neat coils under constant tension to avoid over-stretching or deformation during packaging.

Final Output:

Ready-to-use, flexible, and durable blue 6mm OD 4mm ID pu air hose – ideal for pneumatic tools, air lines, and industrial fluid transfer applications.

Selling Points for our pu hose

High precision: 6mm OD ±0.15mm / 4mm ID ±0.15mm

Excellent abrasion, oil, and weather resistance

Smooth inner wall for minimal pressure drop

Available in custom lengths, packaging, and printing

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