The introduction of acoustic PVB products brought along manufacturing challenges as these new products require more attention to process quality than traditional PVB products. With the new acoustic PVB consisting of a tri-layer structure, glass manufacturers started to suffer from a new kind of lamination defect, today known as "Ice Flower" or "Snowflakes." This is a rather fascinating defect, most likely named this way because of its nature and appearance, but it is especially difficult for manufacturers experiencing it. It is a popular topic of discussion internally between glass makers and their customers. It is also complicated because it is a delayed defect that will appear typically after exposure to changing climate conditions and usually no earlier than in field, therefore creating huge external waste costs. This article reviews the appearance of this quality defect and shows how to control the lamination process to prevent it.
