Polypac Polyurethane U-Cup Seals
Polyurethane U-Cup Seals by Polypac
Precision Engineering & Materials
Polypac Polyurethane U-Cup seals are formulated for superior wear resistance, elasticity and dimensional stability. Manufactured from high-performance polyurethane compounds, our U-Cups maintain sealing integrity across a wide hardness range and operating temperature window. The design concentrates sealing lip contact to reduce friction while ensuring effective fluid retention under dynamic movement.
Performance Advantages
U-Cup geometry plus polyurethane’s inherent toughness provides excellent extrusion resistance, long-term abrasion life and reliable rebound. These seals perform exceptionally in reciprocating and oscillating applications, minimizing leakage and reducing energy loss. Low friction characteristics extend actuator life and improve system efficiency while maintaining pressure capability in demanding hydraulic systems.
Applications & Industries
Polypac Polyurethane U-Cup seals are ideal for hydraulic cylinders, mobile equipment, construction machinery, agricultural systems, industrial presses and marine actuators. They are particularly well suited for heavy-duty, high-pressure environments where wear, contamination and repeated cycling challenge traditional sealing solutions.
Custom Solutions & Production Capacity
With a custom rubber ring and O-ring factory covering over 10,000 m² and 8,000 m² of production space, Polypac supports tailored U-Cup sizes, durometers and compound formulations. Since 2008 we expanded from filled PTFE products to a wide material portfolio (NBR, FKM, silicone, EPDM, FFKM) to meet special working conditions and compatibility requirements.
Quality Assurance & Testing
Our advanced production and testing equipment ensure consistent dimensional accuracy and material performance. Polypac maintains long-term collaborations with universities and research institutions for material development and rigorous lab testing, guaranteeing reliable field performance and traceable quality control.
Why Choose Polypac
Choose Polypac for award-winning technical expertise, scalable manufacturing capability and bespoke sealing solutions. Whether you need a standard polyurethane U-Cup or a tailored compound for extreme conditions, our team delivers optimized sealing performance and responsive support to reduce downtime and total cost of ownership.
Polyurethane U-Cup Display
What is the difference between NBR and FKM materials?
NBR (Nitrile/Buna-N): A general-purpose, cost-effective material with excellent resistance to petroleum-based oils and fuels. It has a standard temperature range of -30°C to +100°C (-22°F to +212°F). FKM (Fluoroelastomer/Viton®): A premium material with excellent resistance to high temperatures (up to 200°C+), chemicals, and oils. It is used in more severe environments but is more expensive than NBR.
When should I use a spring-energized seal instead of a standard elastomeric seal?
Consider a spring-energized seal (e.g., GSF, SPN types) for demanding applications involving: Extreme Temperatures (below -30°C or above +200°C) Aggressive Chemicals that elastomers can't handle Very Low Leakage or "Zero Leakage" requirements Poor Lubricity or dry running conditions The internal spring maintains constant sealing force, compensating for wear and system variables.
What is the purpose of the metal spring in a rotary shaft seal?
The garter spring in a shaft seal (e.g., FSKR, SPGO types) provides a constant radial force on the sealing lip. This ensures consistent contact with the rotating shaft, compensating for minor wear, eccentricity, and vibration to prevent lubricant leakage.
What does "AS568" mean?
AS568 is the Aerospace Standard that defines the dimensions for over 360 standard O-ring sizes. It is the most widely accepted sizing system in North America and globally. An AS568 number (e.g., AS568-214) specifies a precise inside diameter and cross-section.
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