PU Soft Hose for Enhanced Flexibility in Pneumatic and Assembly Applications: A Comprehensive Technical Guide

Introduction

In industrial and manufacturing environments where precision, flexibility, and gentle handling are critical, the PU Soft Hose (폴리우레탄 연질호스) stands out as a specialized solution. This softer-grade polyurethane hose is engineered for applications requiring enhanced flexibility, particularly in low-temperature conditions where standard polyurethane hoses may become rigid. With superior pliability, the PU Soft Hose excels in winter environments and tasks involving delicate line work, such as pneumatic systems and assembly stations. Its ability to reduce mechanical stress on connected components makes it a preferred choice for applications where maintaining hose flexibility is paramount.

Manufactured from a soft polyurethane compound, the hose is available in models such as JPS 0845 (8 × 4.5 mm), JPS 1060 (10 × 6 mm), and JPS 1275 (12 × 7.5 mm). These dimensions ensure compatibility with standard pneumatic fittings while offering a lightweight and pliable design. The PU Soft Hose is tailored for pneumatic lines, assembly stations, and other settings requiring fine control and minimal wear on system components. Its enhanced flexibility and low-temperature performance make it a vital component in industries ranging from electronics manufacturing to automated assembly.

This article provides a detailed technical analysis of the PU Soft Hose, exploring its specifications, materials, key features, applications, comparisons, benefits, limitations, and maintenance guidelines. Aimed at engineers, system designers, and technical professionals, this guide offers actionable insights into how the PU Soft Hose enhances efficiency and reliability in applications demanding gentle handling and flexibility. As industries increasingly prioritize precision and adaptability, the PU Soft Hose delivers a specialized solution that meets these evolving needs.

Technical Overview

The PU Soft Hose is a high-performance tubing solution designed for applications requiring exceptional flexibility and gentle handling. Constructed from a soft-grade thermoplastic polyurethane (TPU) with a Shore A hardness of 70–80—lower than the 85–90 of standard PU hoses—it offers superior pliability, especially at low temperatures. This softness enables the hose to remain flexible down to -30°C, unlike standard PU hoses that stiffen below -20°C, making it ideal for winter environments or refrigerated settings.

Functionally, the hose serves as a conduit for compressed air in pneumatic systems and low-pressure fluid conveyance for non-corrosive liquids like water or mild detergents. Its smooth inner surface, with a roughness average (Ra) of less than 0.3 μm, minimizes flow resistance, achieving pressure drops below 0.08 bar/m for air at 6 bar. The hose’s enhanced flexibility, with a minimum bend radius as low as 8 mm for JPS 0845, allows intricate routing in tight spaces without kinking, reducing mechanical stress on fittings and components.

The hose is manufactured using precision extrusion, ensuring uniform wall thickness (±0.05 mm) and precise outer/inner diameter ratios for compatibility with standard push-to-connect, barbed, or compression fittings. Its lightweight design—ranging from 25 g/m for JPS 0845 to 45 g/m for JPS 1275—enhances handling and reduces fatigue during installation. The soft TPU compound provides a tensile strength of approximately 30 MPa and an elongation at break of 600%, enabling the hose to withstand repeated flexing without cracking.

Chemically, the hose resists oils, greases, and mild detergents, with no significant degradation after 168 hours of exposure at 20°C. Its low moisture absorption (<0.4% by weight) prevents swelling or dimensional changes in humid conditions, ensuring consistent performance. The hose operates reliably from -30°C to 60°C, with short-term tolerance up to 80°C, and is non-conductive, with a dielectric strength of ~20 kV/mm, enhancing safety in electrical environments.

The PU Soft Hose’s design prioritizes flexibility and gentle handling, making it ideal for precision pneumatic applications and delicate assembly tasks. Its compliance with RoHS and REACH standards, along with optional food-grade variants meeting FDA 21 CFR 177.2600, ensures environmental and regulatory compatibility.

Specifications and Dimensions

The PU Soft Hose is available in three primary models, each designed for specific pneumatic and assembly applications. Below is a detailed table of key specifications and dimensions.

Product Code	Outer Diameter (mm)	Inner Diameter (mm)	Wall Thickness (mm)	Weight (g/m)	Minimum Bend Radius (mm)	Working Pressure at 20°C (bar)	Burst Pressure at 20°C (bar)
JPS 0845	8.0	4.5	1.75	25	8	8	24
JPS 1060	10.0	6.0	2.0	35	12	7	21
JPS 1275	12.0	7.5	2.25	45	15	6	18

Additional Specifications:

• Operating Temperature Range: -30°C to 60°C
• Material: Soft-grade thermoplastic polyurethane (TPU)
• Colors: Transparent (standard), custom colors (blue, red, black) available on request
• Length per Coil: 100 m (standard), custom lengths available
• Pressure Derating: 50% at 50°C, 70% at 60°C
• Compliance: RoHS, REACH; food-grade variants meet FDA 21 CFR 177.2600
• Abrasion Resistance: <30 mg loss per DIN ISO 4649
• Moisture Absorption: <0.4% by weight

These specifications ensure the PU Soft Hose meets the needs of precision applications, with smaller sizes (e.g., JPS 0845) ideal for delicate pneumatic lines and larger sizes (e.g., JPS 1275) suited for moderate-flow systems. The lightweight design and precise dimensions enhance compatibility with standard fittings.

Materials and Build Quality

The PU Soft Hose is crafted from a soft-grade thermoplastic polyurethane (TPU), a polyester-based polymer with a Shore A hardness of 70–80, optimized for flexibility and gentle handling. The TPU provides a tensile strength of ~30 MPa and an elongation at break of 600%, allowing the hose to endure repeated flexing and stretching without permanent deformation. Its abrasion resistance, measured at <30 mg loss per DIN ISO 4649, ensures durability in environments with moderate mechanical wear, such as assembly stations.

The hose’s chemical resistance includes compatibility with oils, greases, mild detergents, and water, with no degradation after 168 hours of exposure at 20°C. Its low moisture absorption (<0.4% by weight) prevents hydrolysis, ensuring dimensional stability with less than 0.5% change in diameter or length in humid conditions. The hose’s UV resistance, tested per ISO 4892-2, shows minimal yellowing after 500 hours of exposure, though prolonged outdoor use may require UV protection.

The manufacturing process employs precision extrusion with automated quality control, ensuring uniform wall thickness (±0.05 mm) and a smooth inner surface (Ra < 0.3 μm) to minimize flow resistance and particle buildup. The hose is free of plasticizers, reducing leaching risks, and complies with RoHS and REACH regulations. For food-grade applications, TPU variants meet FDA standards.

Rigorous testing validates the hose’s durability:

• Flexural Fatigue: Over 1.5 million cycles at minimum bend radius without failure.
• Pressure Testing: Burst pressure exceeds 3x working pressure at 20°C.
• Thermal Cycling: No cracking after 500 cycles between -30°C and 60°C.

The soft TPU compound and precision manufacturing contribute to a service life of 7–10 years in typical conditions, with minimal wear on connected components.

Key Features

Enhanced Flexibility

• Minimum bend radius as low as 8 mm enables intricate routing in tight spaces, ideal for delicate line work.

Low-Temperature Pliability

• Remains flexible at -30°C, outperforming standard PU hoses in cold environments.

Lightweight Design

• Weights from 25 g/m to 45 g/m reduce operator fatigue and system load.

Chemical Resistance

• Resists oils, greases, and mild detergents, ensuring reliability in industrial settings.

Gentle Handling

• Soft TPU reduces mechanical stress on fittings and components, extending system lifespan.

Compatibility with Standard Fittings

• Precise dimensions ensure seamless integration with push-to-connect and barbed fittings.

Low Moisture Uptake

• <0.4% moisture absorption maintains performance in humid conditions.

Durable Construction

• Flex-fatigue resistance supports a service life of 7–10 years in precision applications.

These features make the PU Soft Hose a specialized solution for applications requiring flexibility and gentle handling.

Use Cases / Applications

The PU Soft Hose’s enhanced flexibility and gentle handling make it ideal for a range of precision applications.

• Pneumatic Lines in Electronics Manufacturing: The JPS 0845 model delivers compressed air to delicate pneumatic actuators in semiconductor or PCB assembly, where flexibility minimizes stress on components.
• Assembly Stations: Used in automated assembly lines for air supply to grippers and small tools. The JPS 1060 model supports moderate-flow tasks with intricate routing.
• Medical and Laboratory Equipment: Supplies air or gases in devices like ventilators or analytical instruments, with transparent hoses allowing visual flow monitoring.
• Automotive Assembly: Powers precision pneumatic tools in tight spaces, such as dashboard assembly, with the hose’s softness reducing wear on fittings.
• Refrigerated Environments: Maintains flexibility in cold storage or winter conditions, ideal for pneumatic systems in food processing or logistics.
• Robotics and Automation: Supports dynamic connections in robotic arms, with the JPS 1275 model handling moderate airflow in compact setups.
• Aerospace Assembly: Used in precision pneumatic systems for lightweight component assembly, where gentle handling is critical.

Engineers can calculate flow rates using the Darcy-Weisbach equation for gases or Hagen-Poiseuille for liquids, ensuring optimal sizing. The hose’s compatibility with IoT sensors enables real-time pressure monitoring, enhancing system reliability.

Comparison

Below is a comparison of the PU Soft Hose with standard PU, nylon, and braided PU hoses.

Feature	PU Soft Hose	Standard PU Hose	Nylon Hose	Braided PU Hose
Flexibility (Bend Radius)	8–15 mm	10–40 mm	10–100 mm	39–66 mm
Working Pressure (bar)	6–8	7–10	12–25	8–10
Chemical Resistance	Oils, detergents	Oils, acids, alkalis	Oils, acids, alkalis	Oils, detergents
Weight (g/m, Ø10 mm)	35	70	35	60
Cold Resistance	Excellent (-30°C)	Excellent (-20°C)	Excellent (-40°C)	Excellent (-20°C)
Abrasion Resistance	Moderate	High	Moderate	High
Cost per Meter ($)	1.8–3.2	1.5–3.0	1.0–2.5	2.0–3.5

The PU Soft Hose excels in flexibility and low-temperature performance, outperforming standard PU and braided PU hoses in delicate applications. However, it supports lower pressures than nylon or braided PU and has moderate abrasion resistance, limiting its use in high-wear environments.

Benefits and Limitations

Benefits:

• Superior Flexibility: Enables intricate routing and gentle handling in precision applications.
• Low-Temperature Performance: Remains pliable at -30°C, ideal for winter or refrigerated environments.
• Lightweight Design: Reduces operator fatigue and system weight.
• Chemical Resistance: Ensures reliability in oily or wet conditions.
• Reduced Component Stress: Soft TPU extends the lifespan of fittings and connected systems.

Limitations:

• Lower Pressure Capability: Limited to 8 bar, less than nylon or braided PU hoses.
• Moderate Abrasion Resistance: Less durable in high-wear environments compared to standard PU.
• Cost: Slightly higher than standard PU due to specialized soft TPU compound.
• UV Sensitivity: Requires protection for prolonged outdoor use.

The PU Soft Hose’s benefits make it ideal for delicate and cold-environment applications, though its pressure and abrasion limitations require careful application matching.

Maintenance or Care Guide

To maximize the PU Soft Hose’s lifespan:

• Inspection: Check monthly for abrasions, cuts, or kinks. Replace if damage exceeds 10% of wall thickness.
• Cleaning: Use mild soap and water; avoid solvents that degrade TPU.
• Pressure Monitoring: Use gauges to stay within rated limits (6–8 bar), preventing overpressure.
• Storage: Store coils flat in dry, shaded areas below 30°C to prevent deformation.
• Fitting Checks: Tighten fittings to 1.5–2 Nm every 6 months to prevent leaks.
• UV Protection: Apply UV-resistant wraps for outdoor use exceeding 6 months.

Regular maintenance ensures a service life of 7–10 years, with consistent performance in precision applications.

Conclusion

The PU Soft Hose (폴리우레탄 연질호스) is a specialized solution for pneumatic and assembly applications requiring enhanced flexibility and gentle handling. Its soft-grade TPU construction, low-temperature pliability, and lightweight design make it ideal for delicate line work, electronics manufacturing, and cold environments. While it has limitations in pressure capacity and abrasion resistance, its unique flexibility and reliability position it as a valuable asset for precision industrial systems, driving efficiency and longevity in demanding applications.