Are you using the right setting block for your IGU system?
When using an insulating glass unit (IGU), compatibility between the setting block and the rest of the IGU is key. This is particularly true when an IGU uses polyisobutylene (PIB) as its primary sealant.
In 2023, the National Glass Association (NGA) and the Fenestration Glazing Industry Alliance (FGIA) published “Compatibility Testing of Insulating Glass PIB Primary Sealant with Respect to Glazing Materials.” The article highlights the need for compatibility between glazing components and the PIB sealant, stating that there are several potential compatibility issues including “loss of adhesion and/or compromised moisture barrier or gas retention properties as well as negative aesthetic effects.”
Why do I need PIB compatible setting blocks?
It is necessary that the setting block does not affect the PIB sealant. If incompatible material is used for setting blocks, it could result in softening or discoloration of the PIB. All of which points to an unwanted chemical change between the PIB and the setting block. PIB can even migrate through a secondary silicone sealant to reach the setting block, as materials diffuse and try to reach equilibrium.
The NGA/FGIA document identified and validated that the ift Rosenheim test method can be used for determining compatibility.
Why Reed Rubber setting blocks?
Materials such as neoprene setting blocks and EPDM setting blocks can often cause compatibility issues with PIB. Due to concerns with these materials, many manufacturers switched over to silicone setting blocks to avoid compatibility issues. However, silicone is expensive and can drive up costs on building projects.
At Reed, we’ve developed a setting block that is compatible with PIB but costs significantly less than silicone. We’ve tested several of our special thermoplastic blends and three passed the ift Rosenheim test method.
Testing took place over a period of five weeks. The test looked for any changes to contact surfaces, discolorations, or changes to the setting block or PIB including softening or brittleness. Our setting blocks resulted in no visual or physical changes to the PIB, nor to our setting blocks.
Not all fenestration systems require PIB-compatibility. But for customers that do require PIB-compatible setting blocks, we are delighted to offer a more cost-effective alternative to silicone setting blocks. We provide setting blocks for numerous customers that use IGU’s in their fenestration systems, saving them both money and the headache of searching for a compatible material.