Altropol AltroFoam® SF 50 – Flexible Polyurethane Foam 50 kg/m³ for Backfilling & Industrial Parts

Premium Flexible Polyurethane Foam for Professional Backfilling and Industrial Parts

Altropol AltroFoam® SF 50 is a two-component flexible polyurethane foam with a low density that can be processed by hand or by machine. Component A (translucent) and component B (brown) are mixed 100 : 50 by weight, or 95 : 41 by volume. At approx. 500 mPa·s (25 °C) the mixture flows well and starts foaming after approx. 11 seconds. When free-risen, the volume increases about 20-fold, giving a light, flexible foam with a density of approx. 50 kg/m³. The blowing agent contains no fluorinated hydrocarbons and the foam can be used in unheated moulds. AltroFoam SF 50 is intended for component parts for industrial applications and for backfilling cavities.

Professional use: mandatory diisocyanate training

Component B of AltroFoam SF 50 contains diisocyanates. Since 24 August 2023, industrial or professional users may only process this product after completing the mandatory training on the safe use of diisocyanates (REACH Annex XVII, entry 74). Companies can register their employees via safeusediisocyanates.eu. More information can be found on our page working safely with polyurethane and diisocyanates.

Key Benefits

• Density 50 kg/m³: free-risen – a light, flexible foam for fillings where weight matters.
• Expansion approx. 20-fold: little material for a large volume – economical when filling cavities.
• Mix ratio 100 : 50 by weight: simple 2 : 1 ratio – processable by hand or by machine.
• Viscosity approx. 500 mPa·s: free-flowing mixture – fills cavities and moulds evenly.
• Start time approx. 11 seconds: fast reaction – suitable for short production cycles.
• Without fluorinated blowing agents: usable in unheated moulds – no preheating needed for free-rise foaming.

Typical Applications

• Component parts for industrial applications
• Filling cavities and backfilling
• Light, flexible fillings of objects and structures
• Flexible foam parts in unheated moulds

Processing instructions:

1. Bring the material and the workspace to at least 20 °C and work in dry conditions: the system is highly sensitive to moisture.
2. Stir component A thoroughly before use.
3. Weigh A and B accurately in a ratio of 100 : 50 by weight (95 : 41 by volume). For small quantities, use scales accurate to 0.01 gram.
4. For manual processing, first pour component A into the mixing cup, add component B and mix thoroughly straight away, preferably with a high-speed stirrer at approx. 1,000 rpm.
5. Pour the mixture into the cavity or mould immediately, as the start time is approx. 11 seconds, and let it rise freely. Preheating is not needed for this. For integral parts with a rigid skin, preheat the mould to 45 to 50 °C.
6. Close the containers tightly immediately after each use.

Points to Note

• If the mix ratio deviates by more than 3%, the stated properties will not be achieved.
• Larger quantities and higher temperatures shorten the working time considerably. Do not mix too much material at once.
• Altropol has not yet published the rise and tack-free times (preliminary data sheet). Do a small test first with a new mould or cavity.
• Do not use wooden spatulas or stirring sticks.
• Store the product in the tightly closed original container at 20 to 25 °C. The shelf life is stated on the label; the first two digits of the batch number indicate the week, the third digit the year. Use opened containers as soon as possible.

Manufactured by Altropol Kunststoff GmbH, German specialist in polyurethane and epoxy systems for mould and model making.

Professional Support

AltroFoam SF 50 is a light, flexible foam for backfilling and industrial parts. Not sure about the right mould, mixing method or quantity for your foam part? Email us at info@siliconesandmore.com and we will be happy to help.