Polytek PT Flex 97 – Wear-Resistant Polyurethane Casting Rubber Shore A97 for Production Parts & Tooling

PT Flex 97 is a pourable two-component polyurethane rubber that cures quickly at room temperature (RTV) into a very tough, wear-resistant rubber with a hardness of Shore A 95–97. The cured material is yellow/amber and cloudy translucent, and is easy to colour with polyurethane pigments. With a pour time of 4 minutes (250 g) and a demould time of 1 hour at 25 °C, PT Flex 97 is built for fast turnaround. The mix ratio is 1:1 (A:B) by weight; final properties are reached after 7 days. PT Flex 97 is suitable for manual processing and works very well with dispensing cartridges and dispensers.

Key Benefits

• Hardness Shore A 95–97: very tough, dimensionally stable rubber for functional and loaded parts.
• Tensile strength 9–10 N/mm²: high mechanical strength for parts that must absorb forces.
• Tear strength 65–75 N/mm: high resistance to tearing and wear.
• Elongation at break 340–400%: despite its high hardness, the material stays tough and elastic.
• Linear shrinkage <0.2%: dimensionally accurate castings with detail retention.
• Pour time 4 minutes, demould after 1 hour: short cycle time for small series.

Typical Applications

• Production parts and functional parts in small series
• Tools and tooling parts that require wear resistance
• Decorative castings for design and art casting
• Coloured castings using polyurethane pigments
• Model making, props and set building, and rapid prototyping
• Metered processing with dispensing cartridges and dispensers

Processing instructions:

1. Use a non-porous, sulphur-free mould. Seal porous or sulphur-containing models, such as dried clay, with shellac or another well-sealing sealer; for models that are only porous, PVA or lacquer is sufficient.
2. Apply a release agent to sealed and unsealed moulds, preferably a release spray. Silicone moulds usually do not need a release agent. Test in advance whether mould, sealer and release agent are compatible with this polyurethane.
3. Make sure components A and B are at room temperature (20–25 °C) and that the ambient temperature stays above 16 °C throughout the process, including curing. Stir or shake both components in their packaging first.
4. Weigh the components accurately in a ratio of 1 part A to 1 part B (by weight).
5. Mix with a spatula in a clean mixing cup, carefully scraping sides and bottom. Mix by hand, as machine mixing entrains a lot of air.
6. Pour immediately after mixing, within the 4-minute pour time. Do not scrape out the mixing cup while pouring, as the edges may contain poorly mixed material.
7. Allow to cure at room temperature and demould after 1 hour at 25 °C. Final properties are reached after 7 days.
8. Clean tools before the product has cured, using ethanol as a solvent (mind the flammability).

Manufactured by Polytek® Development Corp., a US manufacturer of high-quality casting and mould-making materials for professional and industrial applications.

Important Warning: Diisocyanates and Moisture Sensitivity

Note: component B contains diisocyanates (MDI) and is classified as Danger. It may cause allergic skin and respiratory reactions and is suspected of causing cancer. Component A may cause an allergic skin reaction. Both components are very toxic to aquatic life. Work only in a well-ventilated area and wear nitrile gloves, safety glasses and protective clothing; use respiratory protection with an ABEK-P2 filter if ventilation is inadequate. Since 24 August 2023, diisocyanate training is mandatory for professional and industrial use. The product is moisture-sensitive: store in tightly closed packaging, dry and dark between 15 and 32 °C, preferably under inert gas. Shelf life is at least 6 months. Read the safety data sheets for components A and B before use.

Professional Support

PT Flex 97 is the choice for anyone who wants to cast hard, wear-resistant polyurethane parts quickly and reproducibly. Unsure whether it suits your mould or application? Run a test pour or contact Silicones and More for processing advice and help choosing the right hardness.