FEROPUR E 55 PART B

Reference 421055001

€14.00
16,94 € Tax incl.

FEROPUR E 55 Part B — isocyanate hardener for rigid polyurethane resin PR-55. 1:1 mix ratio by weight/volume. Shore Hardness 75D, demould in 2 min.

Loose Components

Pack of 5 Kg.
Pack of 1 Kg.
Pack of 25 Kg.
Pack of 500gr.

FEROPUR E 55 is component B (hardener, isocyanate base) of the rigid casting polyurethane system FEROPUR PR55+E55. Combined with Part A (PR 55) in a 1:1 ratio, it delivers an ultra-fast room-temperature cure system with excellent flow and high detail reproduction fidelity.

Technical specifications

Parameter	Value
Component	Part B (isocyanate hardener)
Colour	Ivory / yellowish
Mix ratio by weight	100 A : 100 B
Mix ratio by volume	100 A : 100 B
Pot life	80 seconds
Demould time	2 minutes
Shore Hardness (full system)	75D
Cure	At room temperature

What it is used for

This rigid polyurethane system is designed for the production of parts and reproductions requiring high dimensional accuracy and fast demoulding. Its low viscosity and fast reaction speed make it especially suitable for high-volume production with a small number of moulds.

Casting parts in silicone moulds
Making models and prototypes
Production of decorative figures and sculptures
Special effects and props for film and theatre
Architectural reproductions and ornamental parts
Lightweight industrial parts requiring high hardness
Negatives and counter-moulds

How to use it

Shake component B (E 55) thoroughly before use to ensure it is perfectly homogenised.
Also prepare component A (PR 55) and homogenise it in the same way.
Weigh or measure both components in exact proportion 100 A : 100 B (by weight or by volume).
Make sure the mould is completely dry and clean. Apply a release agent if the mould is not silicone or if the part may have undercuts.
Mix both components vigorously and thoroughly for about 20–30 seconds, scraping the sides and bottom of the container.
Pour the mixture into the mould immediately. You have approximately 80 seconds of pot life — act quickly.
Wait 2 minutes before demoulding. The part will continue to fully cure at room temperature over the following hours.
If you wish to add fillers (to adjust viscosity or finish), incorporate them separately into each component before combining them, and disperse thoroughly before mixing.

Important notice — Isocyanates and moisture: Component B (E 55) contains isocyanates. It is moisture-sensitive: contact with water or humid air causes premature reaction and CO₂ bubble formation. Keep the container tightly closed when not in use. Work in low ambient humidity conditions. Wear gloves and safety glasses and ensure adequate ventilation. Consult the safety data sheet before handling.

Usage tips

Temperature and cure speed

The 80-second pot life is very short. In cold environments (below 18 °C) the system may slow slightly, giving a little more working time, but can also produce parts with greater porosity. Ideal working temperature is between 20 and 25 °C. If you need more working time for complex parts, consider pre-warming the mould or preparing the castings in two stages.

Series production

The 2-minute demould time is a real advantage for long production runs: with a single mould you can produce many parts per hour. To maximise output, prepare mixes individually and successively, not in batch. Keep components at a constant temperature and away from direct light between castings.

Using fillers and adjusting viscosity

If you need greater opacity, weight or texture, you can add mineral fillers (calcium carbonate, talc, microspheres) directly into each component separately before mixing. Disperse the filler evenly in each part before combining them. Bear in mind that adding filler increases viscosity and may slightly reduce flow in high-detail areas.

Frequently asked questions

Can I buy only Part B if I already have Part A?

Yes. FEROPUR E 55 is sold as an individual component for those who need to replenish or adjust the quantities of each part separately. Always use it with Part A (PR 55) in a 1:1 ratio. If you prefer the full kit, it is available as FEROPUR PR55+E55.

What should I do if the component has lumps or has gelled?

Gelling of component B is caused by exposure to ambient moisture. If the product has changed consistency or has lumps, it must not be used: the cure of the complete system will be compromised and the result will be porous or incomplete parts. Always keep the container tightly closed and, if possible, store it under inert gas (nitrogen) to extend its shelf life once opened.

Is a release agent needed with silicone moulds?

With tin condensation silicone moulds, FEROPUR PR55+E55 generally does not require a release agent thanks to the naturally low adhesion of silicone. However, for complex geometry moulds, parts with significant undercuts, or after many use cycles, it is recommended to apply a wax or spray release agent to extend mould life and ease demoulding.

Can this resin be pigmented?

Yes. You can add polyurethane pigments to component A before mixing. The recommended amount is low (generally below 5% of total weight) so as not to alter the mechanical properties or cure time. Avoid water-based pigments, as they would cause bubbles through reaction with the isocyanate in component B.

Why are there bubbles in my parts?

Bubbles in rigid polyurethane parts usually have two main causes: moisture in the mould or components, and turbulence during mixing. Make sure the mould is perfectly dry before casting. Mix vigorously but in a controlled manner, avoiding unnecessary air entrapment. If the problem persists, work with the components slightly warmed (25–30 °C) to reduce viscosity and help trapped air escape.

Can the cured part be machined or sanded?

Yes. Once fully cured, FEROPUR PR55+E55 has a Shore Hardness of 75D which allows machining, sanding, drilling and painting without difficulty. For the best finish, wait at least 30–60 minutes after demoulding before machining, although full cure is reached over several hours at room temperature.

Is it suitable for making technical parts such as silent blocks or engine mounts?

No. FEROPUR PR55+E55 is a rigid resin (75D) with no elastomeric properties, so it is not suitable for damping or vibration absorption applications. For silent blocks or other flexible technical parts, you need a specific polyurethane elastomer.

How long can the product be stored unopened?

Stored in its original sealed container, in a cool, dry place away from direct sunlight and heat sources, component B has a shelf life of approximately 12 months. Once opened, close the container immediately after each use and consume it as soon as possible to avoid reaction with ambient moisture.