⭐ Polyester-PU vs. Polyether-PU vs. Polycarbonate-polyester-polyol-PU – Which one to choose? Polyester-PU (like our PU casting system flexible 20/40/60) offers very high abrasion resistance and mechanical strength, ideal for dry applications such as wheels, stamps, and technical parts. Polyether-PU (like the PT Flex series) has excellent resistance to water and...
Polyurethane Casting Rubber (PU Rubber) (8)
⭐ Polyester-PU vs. Polyether-PU vs. Polycarbonate-polyester-polyol-PU – Which one to choose?
Polyester-PU (like our PU casting system flexible 20/40/60) offers very high abrasion resistance and mechanical strength, ideal for dry applications such as wheels, stamps, and technical parts. Polyether-PU (like the PT Flex series) has excellent resistance to water and hydrolysis, perfect for wet or dynamic applications such as pump bushings, valves, and seals. Polycarbonate-polyester-polyol-PU (like the Flexible A75) combines the best of both worlds: the high abrasion resistance of polyester-PU and the better water resistance of polyether-PU. These are the high-end PU rubbers for demanding applications where both mechanical stress and moist conditions play a role.
💡 Choose Polyester-PU for abrasion-resistant, dry applications • Choose Polyether-PU for wet, water-exposed, or flexible parts • Choose Polycarbonate-polyester-polyol-PU for premium applications requiring high abrasion resistance and water resistance
Flexible PU rubber shore A 40–90 for molds & end products
Discover two-component polyurethane casting rubber (RTV PU rubber) for flexible molds and end products. Fast curing, low viscosity, high abrasion resistance and a choice of Shore A 40 to 90 for precisely the right flexibility. Ideal for wear-resistant molds, transport parts and functional rubber products.
⚠️ Please note (Diisocyanates & Training)
Since August 2023, polyurethane with a diisocyanate content > 0.1% may only be processed by companies whose employees have completed the required training course. Ensure proper training/certification before starting, in accordance with EU regulations.
Why choose PU Casting Rubber (Shore A 40–90)?
- ✓Very wear-resistant: long lifespan in production and mold use
- ✓High tensile & compressive strength: performs under load
- ✓Variable hardness: Shore A 40–90 for every application
- ✓Chemical resistance: resistant to oil, petrol and lubricants
- ✓RTV processing: cures at room temperature, quickly demoldable
Applications: molds, transport & end products
Making PU rubber molds
- Wear-resistant molds for concrete, plaster, and industrial use
- High detail reproduction due to low viscosity
Transport & automotive
- Forklift tires, conveyor belt parts (often reinforced)
- Damping blocks and engine mounts – oil/petrol resistant
Creative & end products
- Flexible figures, replicas, and decorative parts
- Functional parts with rubber-like performance
Which Shore A to choose? (40/60/75/85/90)
| Shore A | Property | Typical Application |
|---|---|---|
| ~40 | Flexible, pliable | Detail molds, soft parts |
| ~60 | All-round elastic | Molds with higher wear, damping |
| ~75 | Firm rubber | Smaller production parts, inserts |
| ~85–90 | Hard rubber, very wear-resistant | Industrial rubbers, technical parts |
Assortment of PU Casting Rubber (RTV Urethane Rubber)
PT Flex 60 – Shore A 60 (RTV)
Fast PU rubber with all-round Shore A 60 for molds and production parts. Low viscosity for fine details and easy demolding.
- Applications: decorative pieces, tools, models
- Advantages: fast curing, good wear resistance
PT Flex 85 – Shore A 85 (RTV)
High wear resistance and dimensional stability for demanding end products. Ideal for robust rubber work and small series.
- Applications: production parts, damping blocks, models
- Advantages: fast demolding, high mechanical values
PU Casting System A75 – Shore A ~75
Shore A ~75 for firm, flexible castings. Easy-to-process 2K system; suitable for small to medium-sized parts.
- Applications: molds, replicas, prototypes
- Advantages: ease of use, consistent results
PU Casting System A40 – Shore A ~40
Shore A ~40 for soft, detailed parts and molds. Good workability and clean de-airing.
- Applications: flexible figures, detail molds
- Advantages: pliable, good detail transfer
Processing Tips for 2-Component PU Rubber
- →Work dry & clean: degrease substrate and tools; avoid moisture for optimal curing
- →Accurate mixing: weigh components precisely and mix homogeneously; respect pot life
- →Pouring & de-airing: pour slowly (vacuum if necessary); use suitable release agents
- →Durability: PU is generally more wear-resistant than silicone, but more sensitive to UV/heat; choose finish/coating if needed
- →Safety: PPE, ventilation and diisocyanate training mandatory where applicable
FAQ - Polyurethane Casting Rubber (PU Rubber)
What is RTV polyurethane rubber?
A room temperature vulcanizing 2K PU system that cures at room temperature into flexible rubber. Ideal for molds and end products without an oven.
When do I choose PU rubber instead of silicone?
For wear-resistant molds and parts, or where oil/petrol resistance is needed. Keep in mind the UV/temperature sensitivity of PU.
Which Shore A do I need?
For soft molds, choose A40–A60; for firmer, wear-resistant parts, A75–A90. See the hardness table above for specific applications.
Advice & Ordering
Doubting between Shore A 40, 60, 75 or 85? We are happy to help with the choice, processing and compatibility with your application.
High-Quality Flexible Polyurethane Rubber
Discover our professional polyurethane 2-component systems for making flexible rubber with superior properties. These PU rubbers are ideal for both molds and end products.
NXTlvl made this flexible dragon (Dragan Duma) with PT Flex 85