Natural PU Rod 55mm

6 month ago

18 0 

2 year

Product details

AHD sells both Polyether and Polyester sheets and rods, both belonging to the Polyurethane family. They are similar in many respects; the main difference is that one is water-resistant and the other is oil-resistant. Customers can choose based on their intended use.

Polyether Type (PU Polyether): Extremely superior. The ether bonds (C-O-C) in its molecular chain are chemically stable and not easily broken by water molecules. Therefore, it exhibits excellent stability and a long lifespan in humid, water-immersed, or hot and humid environments.

Polyester Type (PU Polyester): Less desirable. The ester bonds (-COO-) in its molecular chain are prone to hydrolysis under the influence of moisture and heat, leading to material degradation, rapid decline in physical properties, surface cracking, and even pulverization.

Ⅰ. Advantages and Characteristics of PU Plastic Rod

1. Excellent Thermal Insulation Performance: Polyurethane has one of the lowest known thermal conductivity coefficients among solid materials, only 60%~80% of that of traditional insulation materials. Its closed-cell rate is over 90%, effectively hindering air convection and heat conduction, resulting in significant insulation efficiency, making it suitable for scenarios with high energy-saving requirements.

2. Outstanding Water and Moisture Resistance: The closed-cell structure of the polyurethane core material results in extremely low water absorption (≤1%). Even in humid environments or prolonged contact with water, it maintains stable insulation performance and is not prone to mold or rot.

3. Lightweight and Easy to Process: PU is lightweight and can be easily cut, drilled, and machined.

4. High Abrasion Resistance: The abrasion resistance of polyether polyurethane (PU) stems from its unique microstructure. Hard segments form physical cross-linking points, enhancing the material's rigidity, while soft segments impart flexibility to the chain. Simultaneously, the numerous urethane bonds (-NHCOO-) and ether bonds (-O-) in the molecular chain provide excellent cohesive strength, making it less prone to peeling or breakage during friction.

5. High Elasticity: Due to the lower polarity of ether bonds and more flexible chain segments, polyether-type PU exhibits particularly outstanding resilience and resistance to compressive deformation (compression set is often <20%).

6. Tear Resistance: The tear resistance of PU is directly related to the strength of its molecular chains and interfacial bonding. In polyether-type PU, hard segment regions are tightly aggregated through hydrogen bonds, forming a "reinforcing skeleton"; after optimization of the compatibility between soft and hard segments, the interfacial bonding is strong, requiring a higher energy barrier to overcome during crack propagation (i.e., high tearing energy).

7. Weather Resistance and Chemical Resistance

Weather Resistance: The ether bonds (-O-) in polyether-type PU are more stable than the ester bonds (-COO-) in polyester-type PU, resulting in lower sensitivity to water and oxygen and significantly improved hydrolysis resistance (especially in high-temperature and high-humidity environments, where polyester-type PU is easily hydrolyzed and degraded, while polyether-type PU remains stable over a long period).

Chemical Resistance: PU has some resistance to non-polar solvents (such as gasoline and kerosene), but is more sensitive to strongly polar solvents (such as acetone and dimethylformamide). Due to the hydrophobicity of the ether bonds, polyether-type PU has better oil resistance (mineral oil, lubricating oil) than polyester-type PU and is often used in mechanical seals and oil pipe linings. In weakly acidic or alkaline environments (pH 4-9), it is not easily decomposed by short-term contact.

Ⅱ. How to make Polyether Polyurethane Rod you need

Manufacturing high-quality PU (polyether polyurethane) rods requires a focus on precise raw material proportioning, strict control of reaction conditions, optimized molding processes, and post-processing. Let's see how AHD manufactures high-quality PU rods for you.

1. Raw Material Preparation: Selecting the Right Base Components and Controlling Impurities

Carefully select core raw materials and control key aspects:

Dehydrate the polyether polyol to ≤0.05% moisture (to avoid bubble formation during the reaction);

Strictly control the NCO/OH molar ratio of isocyanate to polyol (excess NCO ensures complete reaction and avoids insufficient or excessive crosslinking).

2. Prepolymer Preparation: Precise Reaction and Stable NCO Content

Cool the dehydrated polyether polyol to 80℃, slowly add isocyanate, and react at 80℃±2℃ for 2-3 hours;

Monitor the NCO content in real time to ensure the prepolymer's end-group (-NCO) concentration meets requirements.

3. Chain Extension and Molding: Uniform Crosslinking, Avoiding Defects

Mix the prepolymer and chain extender, stir evenly, and then inject into the mold;

Use casting or compression molding, and cure at 100-120℃ for 4-6 hours to ensure full crosslinking of the molecular chains (forming a stable three-dimensional network structure);

Key Note: Avoid air ingress (vacuum degassing for at least 30 minutes can be used) to prevent bubbles or looseness in the finished product.

4. Post-treatment: Eliminating Internal Stress and Improving Performance

Demolding and Curing: After demolding, allow natural cooling to relax the molecular chains and eliminate internal stress (preventing deformation during subsequent processing);

Fine Finishing: Process the rods to precise dimensions using CNC cutting, grinding, etc.;

Key Quality Control Points

Temperature Control: Avoid exceeding 130℃ throughout the process (easily leads to yellowing or molecular chain degradation);

Impurity Avoidance: Strictly prohibit moisture, oil, and other impurities from entering the raw materials (affecting reactivity and product purity);

Performance Testing: The finished product needs to be tested for tensile strength, elongation at break, compression set, and other indicators.

AHD meticulously controls every detail to produce high-quality, affordable PU rods and provides a stable supply！Contact us for more details.

Ⅲ. Application of PU Rod

1. Automotive Industry: Sealing, Shock Absorption, and Weather-Resistant Components

Sealing Systems: Such as seals for car doors, windows, and engine compartments. Their smooth surfaces and high elasticity effectively fill gaps, preventing rainwater and dust intrusion.

Shock Absorption Components: Shock absorbers and suspension system cushions used in automobiles. Their high elasticity and low compression set effectively absorb road impacts, improving ride comfort.

Weather-Resistant Components: Such as outdoor antenna mounts and wiper brackets. Their UV and ozone resistance properties allow them to withstand long-term outdoor exposure.

2. Medical Equipment: High-Precision and Biocompatible Components

Surgical Instruments: Such as operating table cushions. Their smooth surfaces reduce friction and prevent tissue damage.

Rehabilitation Equipment: Such as wheelchair armrests and prosthetic joint components. Their high elasticity and fatigue resistance allow them to withstand repeated stress.

Medical Sealing Components: Such as IV tubing connectors and medicine bottle seals. Their hydrolysis resistance ensures that medications are not contaminated.

3. Industrial Vibration Damping: Heavy Machinery and Precision Equipment

Heavy Machinery: Vibration damping pads for excavators and cranes, with their high hardness (Shore D 50-70) and large compressive deformation, can absorb vibrations from heavy equipment.

Precision Equipment: Guide rail buffer blocks for CNC machine tools and printing presses, with their low coefficient of friction and high dimensional stability, can reduce equipment wear and improve machining accuracy.

Transportation Equipment: Vibration damping pads for truck beds and buffer sleeves for forklifts, with their impact resistance, can prevent damage from cargo collisions.

4. Outdoor Sports: Low-Temperature Toughness and High Elasticity Components

Snow Sports: Bindings for skis and buffer pads for ice skates, which maintain flexibility at -50℃ to prevent low-temperature cracking.

Outdoor Gear: Shoulder straps for hiking backpacks and ground peg cushioning covers for tents, with their high elasticity and wear resistance to adapt to complex terrain.

Sports Equipment: Gym grips and treadmill belt cushioning pads, with their fatigue resistance, can improve the exercise experience.

5. Other Industrial Sectors

Chemical Industry: Used for corrosion-resistant pump seals and pipe gaskets, whose chemical corrosion resistance (such as acids and alkalis) can withstand the erosion of chemical media;

Food Industry: Such as conveyor rollers and seals in food processing equipment, whose non-toxic and odorless properties meet food hygiene standards;

Electronic Equipment: Such as shock-absorbing brackets for computer hard drives and cushioning pads for mobile phone casings, whose high elasticity and insulation can protect precision electronic components.

Ⅳ. Precautions for Industrial Use of PU Polyether Rods

1. Temperature Control: Avoid high temperatures, utilize low-temperature advantages. As a thermosetting material, long-term use should not exceed 80℃ (decomposition above 120℃); good toughness at low temperatures (-60℃), but for extreme low temperatures (below -50℃), test for cracking first.

2. Chemical Compatibility: Utilize hydrolysis advantages, avoid oil/solvent disadvantages. Resistant to hydrolysis, weak acids and alkalis, water/seawater; avoid mineral oil, aromatic solvents (such as benzene), strong oxidants (such as concentrated sulfuric acid); use with caution in strong acids and alkalis.

3. Mechanical Load: Limit stress, prevent creep. Compression/tension ratio ≤20%, avoid overloading; for high-frequency impact, select high-hardness models (Shore D 60+), pay attention to dynamic fatigue.

4. Processing and Storage: Prevent damage and maintain quality. Use sharp tools for cutting to prevent scorching; store in a cool place, away from sunlight and scratches.

5. Compliant selection for special scenarios

6. Safety and environmental protection: No incineration (producing toxic gases), recycling or disposal in accordance with regulations.