⭐ Polyester-PU vs. Polyether-PU – Which one should you choose? Polyester-PU (such as our PU Rubber 40/60/80) offers very high wear resistance and mechanical strength, ideal for dry applications such as wheels, stampings, and technical components. Polyether-PU (such as the PT Flex series) offers excellent resistance to water and hydrolysis,...
✔ Elastic, Strong, High details
✔ Amber, Fast, High pulling power
✔ Shore A 40
✔ Castings 1mm <> 60 mm.
✔ 23-27 minutes handling time
✔ Mixing ratio (Weight) 100:50
✔ Elastic, Strong, High details
✔ Pale yellow, High tear strength
✔ Shore A 60
✔ Castings 1mm <> 60 mm.
✔ 12 minutes handling time
✔ Mixing ratio (Weight) 100:50
✔ Very high stretch
✔ Elastic, Strong, High details
✔ Amber colored, Good tensile strength
✔ Shore A 20
✔ Can be cast up to max. 60 mm thickness.
✔ 28-34 minutes processing time
✔ Mixing ratio by weight: 100:50
⭐ Polyester-PU vs. Polyether-PU – Which one should you choose?
Polyester-PU (such as our PU Rubber 40/60/80) offers very high wear resistance and mechanical strength, ideal for dry applications such as wheels, stampings, and technical components. Polyether-PU (such as the PT Flex series) offers excellent resistance to water and hydrolysis, perfect for wet or dynamic applications such as pump bushings, valves, and seals.
💡 Choose Polyester-PU for wear-resistant, dry applications • Choose Polyether-PU for wet, water-loaded or flexible parts
Flexible PU rubber shore A 40–90 for molds and finished products
Discover two-component polyurethane casting rubber (RTV PU rubber ) for flexible molds and finished products. Fast curing, low viscosity , high wear resistance, and a choice of Shore A grades 40 to 90 for precisely the right flexibility. Ideal for wear-resistant molds, transport components, 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. Ensure proper training/certification before starting, in accordance with EU regulations.
Why choose PU Casting Rubber (Shore A 40–90)?
✓Highly wear-resistant: long service life in production and mold use
✓High tensile & compression strength: performs under load
✓Variable hardness: Shore A 40–90 for every application
✓Chemical resistance: resistant to oil, petrol and lubricants
✓RTV processing: curing at room temperature, quick to dismantle
Applications: molds, transport & end products
Making PU rubber mold
Wear-resistant molds for concrete, plaster and industrial use
High level of detail due to low viscosity
Transport & automotive
Forklift tires, conveyor belt parts (often with reinforcement)
Damper 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 do you choose? (40/60/75/85/90)
Shore A
Characteristic
Typical Bet
~40
Flexible, bendable
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 versatile Shore A 60 for molds and production parts. Low viscosity for fine detail and easy disassembly.
Applications: props, 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 heavy-duty rubber work and small series.
Applications: production parts, damper blocks, models
Advantages: quick disassembly, high mechanical values
PU Casting System A75 – Shore A ~75
Shore A ~75 for strong, flexible castings. Easy-to-use 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 machinability and clean ventilation.
Applications: flexible figures, detail molds
Advantages: flexible, good detail transfer
Processing tips for 2-component PU Rubber
→Work dry and clean: keep the surface and tools free of grease; avoid moisture for optimal curing.
→Precise mixing: weigh components precisely and mix homogeneously; respect pot life
Pouring& Venting: Pour gently (vacuum if necessary); use suitable release agents
→Resistance: PU is generally more wear-resistant than silicone, but more sensitive to UV/heat; choose a finish/coating if necessary
→Safety: PPE, ventilation and diisocyanate training required 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 to form a flexible rubber. Ideal for molds and finished products without an oven.
When do I choose PU rubber instead of silicone?
For wear-resistant molds and components, or where oil/petrol resistance is required. Keep in mind the UV/temperature sensitivity of PU.
Which Shore A rating do I need?
For soft molds, choose A40–A60; for stronger, wear-resistant parts, choose A75–A90. See the hardness chart above for specific applications.
Advice & Order
Are you unsure whether to choose Shore A 40, 60, 75, or 85 ? We're happy to help with selection, processing, and compatibility with your application.
High-quality flexible polyurethane rubber
Discover our professional two-component polyurethane systems for producing flexible rubber with superior properties. These PU rubbers are ideal for both molds and finished products .
NXTlvl made this flexible dragon (Dragan Duma) with PT Flex 85
