Silicone Based Thermally Broken Anchor for Rain screen Wall Application

In many commercial or industrial buildings, steel or aluminum anchors are used to attach external building components (e.g. cladding) onto internal building structures (e.g. structure walls or sub-frames). These anchors pass through seams in the insulation and transfer climactic load (e.g. wind loads) from the external building component to the internal building structure. Therefore, they can act as a thermal bridge between the exterior and interior building components, which will reduce the overall building insulation performance (e.g. R value). In order to minimize the insulation performance loss caused by the metallic anchors, this study developed a unique silicone based thermally broken anchor for rain screen wall application. Silicone has been widely used in various building projects as coatings, sealants and joint components due to its high durability and good insulation performance. However, very few anchor products on the market have incorporated silicone to achieve better structural or insulation performance, as a silicone-based anchor will require not only structural and insulation performance, but also a demonstrated process feasibility to manufacture it in high volume with low cost. By carrying out performance and process validation testing, this study demonstrated that a silicone based thermally broken anchor can have enough structural capacity and acceptable manufacturability through injection molding. A lab scale hot box insulation test was first performed to compare anchors with and without silicone based thermal break. Then, an injection molding tool was developed to verify its process feasibility for high volume manufacturing. These injection molded silicone-based anchors were tested to evaluate their structural capability with and without aging. It is concluded that silicone based thermally broken anchor can provide enough structural capability and perform as a thermal break at the same time.