What is 2-component PU foam?
Foam sealant is also called pu foam, pur or insulation foam. It is used for all kinds of applications including insulating walls, as well as sealing and filling gaps and cracks in insulation. What exactly is PU foam sealant, what types are there and how does it work? You can read all about it in this article.
- 1k or 2k pu foam
- Froth-Pak sprayable PU foam
- The difference between the three types of foam
- How does foam sealant work?
- Different nozzles
- Conditions of use
- Why maintenance is important
- How to remove PU foam
- Demonstration or advice
1k or 2k PU foam
You can buy foam sealant as one-component foam and two-component foam. The difference here is in how fast the foam cures. 1-component PU foam cures because it makes contact with moisture from the air or the substrate and is relatively slow. With 2-component PU foam, a hardener is added, which cures without the need for moisture. You will also notice this difference when cutting the foam sealant. With 2k pu foam the inside is also fully cured while with 1k pu foam the inside is still soft.
Froth-pak sprayable PU foam
A common brand of foam kit is Froth-Pak. Sprayable PU foam is available in several variants. Depending on the application, one can choose the Froth-Pak Quick Rise, Froth-Pak Slow Rise or Froth-Pak High Density. The difference between the Quick Rise and Slow Rise can already be seen from the names. The polyurethane foam of the Slow Rise rises and cures slowly, while the Quick Rise cures very quickly.
The difference between the three types of foam sealant
The Slow Rise is especially important when injecting polyurethane foam, also known as in-situ foams. This gives the foam time to reach all holes and corners before it cures. Quick Rise is often used on walls so that one can work through quickly. The High Density PU-foam has a higher density per m3 and is specially developed for applications where this density of 40 – 45 kg/m3 is required.
How does foam sealant work?
The 2k pu foam kit consists of two disposable tanks of 6kg or 20kg per component, which are pressurised, containing separately a foamer and a hardener. A hose set is connected to this, which is connected to a PU foam gun. When the tanks are opened and the sprayer is squeezed, foaming begins. No experience with sprayable PU foam? We also provide on-site explanations and demonstrations, please contact our technical specialists.
Various nozzles for sprayable PU foam
The nozzle, which is clicked onto the foam gun, has a mixing chamber. This is where the two components meet and ensure even distribution before being sprayed onto the product. When the foam and hardener are mixed, a chemical reaction occurs, causing the polyurethane foam to first increase in volume, or rise, and then cure.
Depending on the application, there are different nozzles. The cone nozzle is an all-round nozzle that ensures even distribution and is ideal for in-situ foaming. The spray nozzle, on the other hand, is suitable for spraying surfaces. When you stop foaming, the spray nozzle should be replaced after about 30 seconds because the foam then starts to harden. It is therefore important to prepare as much as possible before you start foaming.
Conditions of use 2k pu foam
Applying PU foam insulation is not difficult, but you need to take a few things into account. For optimum efficiency and best quality, it is important that the foam set is at temperature during use. A good usage temperature is between 23 and 27°C degrees. This can be done by placing the kit in a heat cabinet or with heat ribbons around it. The better the foam kit is at temperature, the higher the efficiency.
Why foam sealant maintenance is important
Maintenance is very important with PU foam insulation. Not only cleaning after use, but also regular flushing of the hose set contributes to a longer life. When this is not done, crystallisation occurs, causing the system to block. In addition, it can cause the mixing ratio to be incorrect, which also results in poor quality foam insulation.
How do you remove sprayable PU foam?
Sprayable PU foam is a dense and firm foam with a high insulation value, so you won’t get it off easily. You cannot remove foam with thinner or white spirit, but only with a special PU foam cleaner. With the foam gun, you can inject the 2k PU foam very accurately, but there is always a chance of spilling. Also your gun needs to be cleaned after use. With PU foam cleaner, you will remove foam spots not only from the gun, but also from your clothes and sheet metal.
Contact us for advice or a demonstration
Do you have questions about using 2k PU foam or need advice on your insulation project? Our specialists are at your service and take all the time to give your employees training and explanations where they can also foam themselves. Together we look at the best way to make your insulation project a success!