High-performance cast polyurethane elastomer systems for hydraulic and pneumatic seals and gaskets — rod seals, piston seals, wiper/scraper seals, O-rings and mechanical gaskets. Engineered for low compression set, high extrusion resistance under pressure (up to 35 MPa) and excellent wear life. Polyether (water-glycol) and polyester (mineral-oil) systems available; hardness and chemistry tuned to your fluid and duty.
35 MPa
Pressure / extrusion rating
< 25%
Compression set (70 °C / 22h)
A60–D75
Hardness Shore
Oil/H₂O
polyester / polyether
−40~110
Service temp °C
Key Features
Low compression set < 25% at 70 °C / 22h (ASTM D395) for reliable long-term sealing force.
High extrusion resistance Holds the seal lip under high-pressure cycling up to 35 MPa.
Hydrolysis-resistant polyether For water-glycol and water-based hydraulic fluids.
Oil-resistant polyester For mineral-oil hydraulic fluids and lubricated dynamic seals.
Superior wear life Outlasts standard EPDM / NBR at elevated temperature and pressure.
Customizable formulation Hardness, chemistry and lip profile tuned to your fluid and cylinder. OEM/ODM.
Applications
Hydraulic Rod SealsPiston & Rod SealsCast PU O-RingsV-Rings & Rotary Seals
Also used for: wiper / scraper seals, mechanical face gaskets, pneumatic actuator seals and custom dynamic sealing elements.
Technical Specifications
Property
Range
Test Method
Hardness
Shore A 60 – Shore D 75
ASTM D2240
Tensile strength
20–55 MPa
ASTM D412
Elongation at break
250–650%
ASTM D412
Compression set
< 25% (70 °C / 22h)
ASTM D395
Tear strength
60–120 kN/m
ASTM D624
Abrasion resistance
20–80 mm³
DIN 53516
Working pressure
up to 35 MPa
—
Operating temperature
−40 °C to +110 °C continuous
ISO 9142
Parameters customizable by formulation; typical values for reference, not a binding specification.
Casting Processes
Open-Mold Casting For seal rings, gaskets and machined-blank tubes.
Centrifugal Casting Void-free tubular blanks for machined seals and rings.
Vacuum Casting Precision, void-free O-rings and dynamic seal profiles.
Automated Casting Compatible with PU casting machines and automated dispensing.
Packaging, Storage & Handling
Packaging Prepolymer and curative supplied in iron drums; palletised for export. Bulk on request.
Storage Store sealed in a cool, dry, ventilated area away from moisture. Shelf-life details on request.
Handling & Safety Avoid eye/skin contact; wear safety glasses. Wash skin with soap and water; flush eyes with water and seek medical attention. Full MSDS on request.
One-Stop PU Elastomer Solution
Beyond raw materials, BlendPolyol provides matched equipment and tooling — a complete production-line partner, not just a chemical supplier:
10+ years in PU raw materials Specialised PU elastomer & polyol manufacturer serving industry worldwide.
Custom formulation Hardness, chemistry and lip profile tuned to your fluid and cylinder.
Equipment integration Casting machines, mixing systems and seal moulds as a complete solution.
Global export & fast reply Export to EU, Latin America, Asia and beyond — we respond within 24 hours.
From Sample to Bulk Order
1. Share your spec Tell us seal type, fluid, pressure and temperature — we recommend polyether or polyester.
2. Sample & validate Trial-cast seals; we fine-tune hardness, profile and chemistry resistance.
3. Scale to bulk Confirm the formula and order in bulk with flexible MOQ and tiered lead times.
Frequently Asked Questions
Polyether or polyester for my fluid?Polyether resists hydrolysis — choose it for water-glycol / water-based fluids and humid service. Polyester offers higher mechanical strength and oil resistance — choose it for mineral-oil hydraulics.
What pressure can the seals handle?Up to about 35 MPa with good extrusion resistance; for higher pressure we recommend a harder grade or anti-extrusion back-up ring.
Why PU instead of NBR/EPDM?Cast PU offers higher tear and abrasion resistance and longer life at elevated pressure and temperature, with excellent extrusion resistance.
Can the formulation be customized?Yes. Hardness, chemistry and seal profile are all customizable. OEM/ODM supported — request a TDS, MSDS and sample; we reply within 24 hours.
Need PU elastomer for seals & gaskets?
Get a tailored formulation, full TDS & MSDS, and a sample for casting validation.
✓ Polyether & polyester✓ TDS · MSDS · COA✓ Reply within 24 h
Please complete the form below and our customer support team will be in touch with you shortly. Inquiries submitted through this form will receive priority processing over emails.
