Low Friction PU Rod for Machinery Sliding Surfaces

4 week ago

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Foshan Anheda New Material Co., Ltd

 2 month year

Product details

Low Friction PU Rod for Machinery Sliding Surfaces

Polyurethane Rod, as a typical representative of high-performance engineering material systems, derives its core value from the cross dimensional performance brought about by the molecular designability of polyurethane (PU) materials. By precisely regulating the reaction kinetics of isocyanates and polyols, PU rods have achieved a continuous performance transition from elastomers to quasi rigidity. Their density can be precisely controlled within the range of 0.9~1.5 g/cm ³, and their tensile strength covers the range of 35~90 MPa, while maintaining excellent mechanical integrity over a wide temperature range of -60 ℃ to 120 ℃. The molecular basis of this material system consists of hard segments and soft segments: the hard segments are derived from the reaction products of diisocyanates (such as MDI, TDI) and chain extenders, forming highly regular crystal structures or ordered regions, endowing the material with high strength, high rigidity, and heat stability; Soft segments rely on polyether glycol (PTMEG) or polyester glycol (PBA) to construct a flexible chain segment network, achieving high resilience and fatigue resistance through segment entropy elasticity and dynamic relaxation mechanisms. Molecular dynamics simulations show that in the load-bearing state, the soft segment of PU rod can quickly dissipate energy through conformational adjustment, while the hard segment structure forms a physical cross-linking point network, jointly constructing an "energy sponge" mechanism. Its loss factor (tan δ) can be adjusted in the range of 0.05~0.3, significantly better than traditional thermoplastic materials.

pu rod

The refined control of production processes further expands the performance boundaries of PU rods. The continuous casting process adopts two-component in-situ polymerization technology, and the equivalent ratio of isocyanate (component A) to polyol (component B) is precisely controlled within the range of 1:1 ± 0.02 through a precision metering pump. Combined with a gradient pressure control of -0.05~0MPa, a dense and bubble free structure is formed, with a density uniformity of ± 0.02 g/cm ³. The injection molding process optimizes the temperature gradient of the mold for complex cross-sectional structures (inlet 280 ℃ → outlet 80 ℃), forming a dense layer (thickness 50-200 μ m, Vickers hardness ≥ 60 Shore D) on the surface of the rod and a dual microstructure of high toughness areas in the core. The reaction injection molding (RIM) process combined with fiber reinforcement technology for special grades can prepare reinforced PU rods with a surface density greater than 99% and an internal fiber volume fraction of 30%. The bending modulus can reach 20 GPa, which is 300% higher than that of ordinary grades. The scientific combination of additive systems constitutes another key path for performance improvement - silane coupling agent modified nano alumina (particle size 20-50nm) filling can enhance wear resistance (volume wear<0.02 mm ³/(N · m)), phosphorus based flame retardant system increases LOI value from 18% to 28%, and nanocellulose whisker reinforcement endows the material with excellent dynamic dimensional stability (linear expansion coefficient ≤ 20 × 10 ⁻⁶/℃).

pu rods

Performance advantages build the core value of engineering applications

The performance advantage of PU rod comes from the synergistic optimization of its molecular structure and processing technology. Dynamic mechanical analysis (DMA) shows that its storage modulus (E ') maintains a plateau region of>1 GPa above the glass transition temperature (Tg ≈ -30 ℃ to 100 ℃), which is 5-8 times higher than that of ordinary elastomers, making it possess both the load-bearing capacity of structural materials and the impact resistance characteristics of elastomers. In an extremely cold environment of -60 ℃, PU rods still maintain an initial elastic modulus of over 80%, with an impact strength of 15 kJ/m ², which is superior to most engineering plastics. The compression performance test shows that at 25% strain, the PU rod can withstand cyclic loads greater than 100 MPa, with a hysteresis loss coefficient of less than 0.15, demonstrating excellent fatigue resistance.

The environmental resistance performance demonstrates the fine tuned art of materials science - for strong acid and alkali environments, by introducing chain extenders containing silicon and fluorine groups, a hydrophobic and oleophobic molecular barrier layer can be constructed, which enables PU rods to maintain volume stability<0.5% in the pH range of 1-14. Temperature resistance tests show that after 5000 hours of hot air circulation aging at 150 ℃, the strength retention rate is>85%, far exceeding the industry benchmark (≥ 70%). Special functional modification technology endows PU rods with more application potential: adding graphene nanosheets (content 2-5wt%) to increase the conductivity from the insulating state (>10 ¹⁵Ω· cm) to 10 ⁻ S/m, successfully applied in electromagnetic shielding conditions; Doping of photothermal conversion materials (such as MXene) enables remote temperature control function, triggering local temperature rise (Δ T>25 ℃) through near-infrared radiation for thermal management of intelligent fluid pipeline systems.

pu rod material