Feropur PR55 WHITE is a two-component rigid polyurethane resin in white, formulated for casting at room temperature. With a 1:1 mix ratio by weight and a cure time of just 10 minutes, it is the ideal choice when you need to produce series parts with high detail fidelity without long waiting times between demouldings.
Technical specifications
Parameter
Value
Application type
Casting
Colour
White
Shore Hardness
75D
Mix ratio (by weight)
100A : 100B
Working time
2 minutes
Cure time
10 minutes
What it is used for
Feropur PR55 WHITE is designed for the reproduction of fine-detail parts and for series production, especially when a rigid white material is needed to facilitate finishing and subsequent painting. It is commonly used for:
Reproduction of decorative pieces and sculptures in silicone moulds
Manufacture of prototypes and scale models
Series production of figurines, ornaments and architectural elements
Replicas of objects for collecting and special effects
Lightweight technical parts requiring subsequent machining
Educational and modelling applications
How to use it
Shake component A (resin/polyol) vigorously before use to ensure proper homogenisation of the product.
Weigh the required amounts of each component in the proportion 100A : 100B by weight using a precision scale.
If you are working with fillers, incorporate them separately into each component and disperse thoroughly before mixing.
Mix both components for at least 30–60 seconds until a homogeneous, streak-free mass is obtained. You have a working time of 2 minutes, so work swiftly.
Pour the mixture into the dry mould. If the mould is not made of silicone, apply a release agent beforehand to facilitate demoulding.
Allow to cure at room temperature for 10 minutes. Once that time has elapsed, the part can be demoulded and is ready for machining or painting.
Important notice — Polyurethane resin (isocyanates): Component B contains isocyanates. Always work in a well-ventilated space and use nitrile gloves, safety goggles and, if ventilation is insufficient, a respirator with an organic vapour filter. Avoid contact with skin and eyes. Keep containers tightly closed when not in use, as component B is moisture-sensitive and may gel if exposed to air. Consult the safety data sheet before handling the product.
Usage tips
Temperature and humidity
Always work between 18 °C and 25 °C. Below this temperature the working time increases and curing is slower, but the risk of trapped bubbles also rises. At higher temperatures, the working time shortens even further. Avoid working in environments with relative humidity above 70%: the isocyanate reacts with water vapour and can generate bubbles or reduce the final properties of the part.
Series production and demoulding
Thanks to the 10-minute cure time, you can reuse the same mould very quickly. However, although the part can be demoulded at 10 minutes, final mechanical properties are reached after 24 hours. If you plan to machine, sand or bond the parts, wait that time. For long production runs in non-silicone moulds, renew the layer of paste release agent every few castings.
Use with fillers and pigments
You can adjust the viscosity and properties of the material by adding mineral fillers (talc, calcium carbonate, etc.) to each component separately before mixing them. This allows you to achieve heavier parts, different textures or to reduce the cost per part. If you need to colour the resin, use pigments specifically designed for polyurethane and add them to component A before mixing. Bear in mind that any external additive may modify the working time and cure.
Frequently asked questions
Do I need a release agent to use this resin?
It depends on the mould material. With silicone moulds it is generally not necessary, as silicone naturally acts as a non-stick surface. With moulds made of other materials (polyester, plaster, wood, metal), it is essential to apply a release agent before each casting to prevent the part from sticking and to facilitate demoulding without damaging either the part or the mould.
What happens if I mix the proportions incorrectly?
An imbalance in the Feropur PR55 WHITE mix can result in a part that does not cure fully, remains tacky or loses mechanical strength. Always use a precision scale and respect the 100A : 100B ratio by weight. Do not rely on volume measurements: the densities of both components may differ.
Can I use this resin in plaster moulds?
Yes, you can cast Feropur PR55 WHITE in plaster moulds, but you must ensure the mould is completely dry before use. Residual moisture in the plaster would react with the isocyanate and generate bubbles in the part. Apply several coats of release agent and allow each coat to dry thoroughly before the first casting.
Can it be painted or sanded once cured?
Yes. Once fully cured (24 hours), Feropur PR55 WHITE can be sanded, milled and painted without any issues. Its white base colour facilitates the application of paints and finishes, as it does not affect the tone of the final coating. For acrylic or water-based paints, light sanding beforehand improves adhesion.
How long do I have to work with the mixture before it sets?
The working time of Feropur PR55 WHITE is approximately 2 minutes from the moment you mix the two components. Within that time you must complete the mixing and pour into the mould. Do not attempt to mix large volumes if you are not experienced with fast-setting resins: work in manageable quantities and have everything ready before you begin.
Is it suitable for contact with food or skin?
No. Feropur PR55 WHITE is not certified for food contact or for prolonged use on skin. If you need a resin for food-contact applications, consult Feroca about products specifically certified for that use.
What is the difference between this resin and the clear version?
The main difference is colour. Feropur PR55 WHITE is formulated to produce opaque white parts, which facilitates subsequent painting and prevents the original part colour from "contaminating" the finish. The Feropur PR55+E55 version produces translucent or ivory-toned parts. Both have the same mechanical and processing characteristics.
Can I buy the components separately?
Yes. Feroca sells Part A (Feropur PR 55) and Part B (Feropur E 55) separately, allowing you to replenish whichever component runs out first without having to purchase a complete kit.
How much product do I need?Calculate the exact amount before buying and avoid wasting material.
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