PolyFoam R2 -Rigid Polyurethane Foam-

PolyFoam R2 is a two-component rigid polyurethane foam with a volumetric expansion of between 8 and 15 times its initial volume. Formulated without TDI, MOCA, heavy metals or HCFC, it is virtually odourless and offers an excellent level of surface detail. Ideal for lightweight fills, prototypes and part series when you need a rigid, precise and easy-to-use foam.

Technical specifications

What it is used for

PolyFoam R2 is designed for applications where a rigid, lightweight structure with good detail reproduction is needed. Its low free rise density and excellent fill capacity make it a go-to choice for the production of decorative parts and technical models:

• Filling hollow parts to add rigidity without excessive added weight
• Decorative objects, props and set pieces
• Lightweight mother moulds for reinforcing silicone moulds
• Series production of parts from polyurethane resin moulds
• Low-density models and prototypes
• Duplicating masters and patterns
• Internal structures for articulated figures or special effects props

How to use it

1. Prepare the mould. Make sure the mould — preferably platinum silicone or polyurethane rubber — is clean, dry and properly closed. Apply a Release agent if the mould material requires it.
2. Condition the components. Bring components A and B to working temperature (between 20–25 °C). Stir each component separately before mixing, as component A may settle.
3. Weigh or measure in a 1:1 ratio. Mix equal parts by weight or by volume. Use a precision scale or graduated containers.
4. Mix vigorously for 20–30 seconds. Scrape the sides and bottom of the container thoroughly. The mix will begin to cream almost immediately — you have approximately 30 seconds of usable working time.
5. Pour into the mould immediately. Given the very short cream time, pour as soon as the mixture is homogeneous. For closed parts, fill only the required volume by calculating the expected expansion (8–15x).
6. Close the mould and clamp it. The expansion pressure can be considerable. Use clamps, G-clamps or clamping systems to prevent the mould from opening during the process.
7. Allow to cure for 30 minutes before demoulding. At room temperature, the part reaches sufficient hardness for demoulding in 30 minutes. Full cure continues over the following hours.

Usage tips

Calculate the fill volume carefully

The foam can expand up to 15 times its initial volume. If you overfill a closed mould, the expansion pressure can damage the mould or cause leaks. As a reference, for a moulded density of 64 kg/m³ starting from a free rise density of 40 kg/m³, you will need to calculate the cavity volume and the actual expansion factor based on the mould restriction. Run tests with small amounts before producing in series.

Recommended moulds and release agents

Platinum silicone moulds are the preferred option for PolyFoam R2: in most cases they require no Release agent thanks to their non-stick nature. However, the foam is self-adhesive on many substrates (wood, cardboard, existing foam, fabrics), which is advantageous when the goal is permanent fill of a part. If you use resin or plaster moulds, always apply a Release agent in a thin, even layer to facilitate demoulding without damaging the surface.

Ambient temperature and humidity

Temperature is the factor that most affects reaction speed. Above 25 °C, cream time shortens even further and expansion is faster. Below 18 °C, cure slows down and surface problems may appear. Always work at a stable temperature between 20 and 25 °C. High humidity can introduce extra CO₂ into the mix and slightly increase surface porosity; in very humid environments, condition the mould before pouring.

Frequently asked questions